Ultra-low shrinkage composite resins based on blended nematic liquid crystal monomers

• US 20030125435A1
• Filed: 03/07/2002
• Published: 07/03/2003
• Est. Priority Date: 03/07/2001
• Status: Active Grant

• Current Assignee: University of Texas System
• Original Assignee: University of Texas System
• Inventors: Satsangi, Neera, Norling, Barry K.
• Granted Patent: US 7,094,358 B2
• Time in Patent Office: Days
• US Class Current: 524/287
• CPC Class Codes: C08G 63/60 derived from the reaction of a mixture of hydroxy carboxylic acids, polycarboxylic acids and polyhydroxy compounds
• CPC Class Codes: C08G 63/605 the hydroxy and carboxylic groups being bound to aromatic rings
• CPC Class Codes: C09K 19/2007 the chain containing -COO- or -OCO- groups
• CPC Class Codes: C09K 2019/0448 the end chain group being a polymerizable end group, e.g. -Sp-P or acrylate

Abstract

A novel method of making liquid crystal monomers, novel monomer blends, and novel secondary monomers for use in such blends. The blends remain in a nematic state after additing inorganic filler, and exhibit low cure shrinkage.

Claims

1. A method comprising:

providing a 4-hydroxyl benzoic acid comprising a carboxyl substituent;

providing an alkylene group comprising an α

-hydroxyl group and an ω

-halide group;

condensing said 4-hydroxyl of said benzoic acid with said ω

-halide group under conditions effective to produce a hydroxyl terminated alkyloxy comprising said α

-hydroxyl group at a first terminus and said carboxyl substituent of said 4-hydroxyl benzoic acid at a second terminus.

2. The method of claim 1 wherein said ω

-halide group is an ω

-chlorine.

3. The method of claim 1 wherein said alkylene group comprises from about 2 to about 12 carbon atoms.

4. The method of any of claims 2 wherein said alkylene group comprises from about 2 to about 10 carbon atoms.

31. The method of claims 1 producing a yield of said alkanol ethereal benzoic acid of about 90% or more.

5. A method comprising:

providing a 4-hydroxyl benzoic acid comprising a carboxyl substituent;

providing an alkylene group comprising an a-hydroxyl group and an ω

-halide group;

condensing said 4-hydroxyl of said benzoic acid with said ω

-halide group under conditions effective to activate said carboxyl group and to produce a hydroxyl terminated alkyloxy comprising said α

-hydroxyl group at a first terminus and an activated carboxyl substituent of said 4-hydroxyl benzoic acid at a second terminus;

reacting a polymerizable group with said first terminus under conditions effective to produce an ethereal benzoic acid comprising said activated carboxyl substituent in a position para- to a polymerizable terminus; and

,

providing a hydroquinone comprising a bulky organic group and comprising a first hydroxyl group para- to a second hydroxyl group, at least one of said first hydroxyl group and said second hydroxyl group being an ionically activated hydroxyl group;

condensing said at least one ionically activated hydroxyl group of said hydroquinone with said activated carboxyl substituent of said ethereal benzoic acid under conditions effective to produce a compound comprising at least two aromatic rings joined by an ester linkage and comprising a polymerizable terminus and a terminus selected from the group consisting of a second polymerizable terminus and said second hydroxyl group of said hydroquinone.

6. The method of claim 5 wherein said ω

-halide group is an ω

-chlorine.

7. The method of claim 5 wherein said alkylene group comprises from about 2 to about 12 carbon atoms.

8. The method of claim 6 wherein said alkylene group comprises from about 2 to about 10 carbon atoms.

9. The method of claim 7 wherein said polymerizable group is selected from the group consisting of a nucleophile and groups comprising at least one electron deficient alkene.

10. The method of claim 7 wherein said polymerizable group is selected from the group consisting of a nucleophile and groups comprising at least one electron deficient alkene.

11. The method of claim 7 wherein said polymerizable group is selected from the group consisting of ester groups, organic acid groups, amine groups, hydroxyl groups, and sulfhydryl groups.

12. The method of claim 7 wherein said polymerizable group is an electron deficient alkene independently selected from the group consisting of substituted and unsubstituted alkenyl ester groups comprising a polymerizable unsaturated carbon—

carbon bond, wherein said alkenyl group has from about 2 to about 12 carbon atoms.

13. The method of claim 8 wherein said polymerizable group is an electron deficient alkene selected from the group consisting of alkenyl esters, acryloyl groups, and methacryloyl groups.

14. The method of claim 13 wherein said bulky organic group is adapted to generate asymmetry in packing of said nematic liquid crystal monomer and to provide sufficient steric hindrance for said nematic liquid crystal monomer to achieve a nematic state at processing conditions while suppressing crystallization of said nematic liquid crystal monomer at processing conditions.

15. The method of claim 14 wherein said processing conditions comprise a temperature of from about 20°

C. to about 40°

C.

16. The method of claim 13 wherein said bulky organic group is selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups.

17. The method of claim 13 wherein said bulky organic group is a t-butyl group.

18. A method comprising:

providing a 4-hydroxy benzoic acid comprising a carboxyl substituent;

providing an alkylene group comprising an α

-hydroxyl group and an ω

-halide group;

condensing said 4-hydroxyl substituent of said benzoic acid with said ω

-halide group under conditions effective to produce a hydroxyl terminated alkyloxy comprising said α

-hydroxyl group of said alkylene group at a first terminus and said carboxyl substituent of said benzoic acid at a second terminus;

reacting a polymerizable group with said first terminus under conditions effective to produce an ethereal benzoic acid comprising said activated carboxyl substituent in a position para- to a polymerizable terminus; and

,

providing a hydroquinone comprising a bulky organic group and comprising a first hydroxyl group para- to a second hydroxyl group, at least one of said first hydroxyl group and said second hydroxyl group being an ionically activated hydroxyl group;

condensing said at least one ionically activated hydroxyl group of said hydroquinone with said activated carboxyl substituent of said ethereal benzoic acid under conditions effective to produce a nematic liquid crystal comprising three aromatic rings joined by an ester linkage and comprising at least a first polymerizable terminus.

19. The method of claim 18 wherein said ω

-halide group is a ω

-chlorine group.

20. The method of claim 18 wherein said alkylene group comprises from about 2 to about 12 carbon atoms.

21. The method of claim 19 wherein said alkylene group comprises from about 2 to about 10 carbon atoms.

22. The method of claim 20 wherein said polymerizable group is selected from the group consisting of a nucleophile and groups comprising at least one electron deficient alkene.

23. The method of claim 20 wherein said polymerizable group is selected from the group consisting of ester groups, organic acid groups, amine groups, hydroxyl groups, and sulfhydryl groups.

24. The method of claim 20 wherein said polymerizable group is an electron deficient alkene independently selected from the group consisting of substituted and unsubstituted alkenyl ester groups comprising a polymerizable unsaturated carbon—

carbon bond, wherein said alkenyl group has from about 2 to about 12 carbon atoms.

25. The method of claim 21 wherein said polymerizable group is an electron deficient alkene selected from the group consisting of alkenyl esters, acryloyl groups, methacryloyl groups.

26. The method of claim 25 wherein said bulky organic group is adapted to generate asymmetry in packing of said nematic liquid crystal monomer and to provide sufficient steric hindrance for said nematic liquid crystal monomer to achieve a nematic state at processing conditions while suppressing crystallization of said nematic liquid crystal monomer at processing conditions.

27. The method of claim 26 wherein said processing conditions comprise a temperature of from about 20°

C. to about 40°

C.

28. The method of claim 25 wherein said bulky organic group is selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups.

29. The method of claim 25 wherein said bulky organic group is at-butyl group.

30. The method of claim 18 producing a yield of said nematic liquid crystal of about 50% or more.

32. The method of claim 18 wherein said polymerizable group is a methacryloyl group, and said method has a product yield of said nematic liquid crystal about 80% or more.

33. A resin blend comprising inorganic filler and a primary liquid crystal monomer at a ratio to a secondary monomer, said secondary monomer and said ratio being adapted to maintain said resin blend in a nematic liquid crystalline state for about 30 minutes or more after addition of an inorganic filler at a temperature of 20°

C.

34. The resin blend of claim 33 wherein said resin blend maintains said nematic liquid crystalline state for about 1 hour or more.

35. The resin blend of claim 33 wherein said resin blend maintains said nematic liquid crystalline state for about 4 hours or more.

36. The resin blend of claim 33 wherein said resin blend maintains said nematic liquid crystalline state for about 6 months or more.

37. The resin blend of claim 35 wherein said liquid crystal monomer has the following general structure:

38. The resin blend of claim 37 wherein said polymerizable groups comprise electron deficient alkenes.

39. The resin blend of claim 38 wherein R² is selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups.

40. The resin blend of claim 38 wherein R² is a t-butyl group.

43. The resin blend of claim 37 wherein A comprises from about 2 to about 10 carbon atoms.

44. The resin blend of claim 37 wherein A comprises from about 2 to about 6 carbon atoms.

42. The resin blend of claim 42 wherein R² is a t-butyl group.

41. The resin blend of claim 42 wherein R² is selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups.

46. A resin blend comprising inorganic filler and a primary liquid crystal monomer at a ratio to a secondary monomer, said ratio and said secondary monomer being adapted to maintain said resin blend in a nematic liquid crystalline state for about 30 minutes or more after addition of an inorganic filler at a temperature of 20 °

C., wherein said blend exhibits about 4 vol. % or less polymerization shrinkage.

45. The resin blend of claim 46 wherein A has 6 carbon atoms.

47. The resin blend of claim 46 wherein said blend exhibits about 2 vol. % or less polymerization shrinkage.

48. The resin blend of claim 46 wherein said blend exhibits about 1.5 vol. % or less polymerization shrinkage.

49. The resin blend of claim 46 wherein said blend maintains said nematic liquid crystalline state for about 1 hour or more.

50. The resin blend of claim 46 wherein said blend maintains said nematic liquid crystalline state for about 4 hours or more.

51. The resin blend of claim 46 wherein said blend maintains said nematic liquid crystalline state for about 6 months or more.

52. The resin blend of claim 47 wherein said blend maintains said nematic liquid crystalline state for about 4 hours or more.

53. The resin blend of claim 47 wherein said blend maintains said nematic liquid crystalline state for about 6 months or more.

54. The resin blend of claim 46 wherein said liquid crystal monomer has the following general structure:

55. The resin blend of claim 52 wherein said liquid crystal monomer has the following general structure:

56. The resin blend of claim 55 wherein said polymerizable groups are nucleophiles selected from the group consisting of ester groups, organic acid groups, amine groups, hydroxyl groups, and sulfhydryl groups.

57. The resin blend of claim 55 wherein said polymerizable groups comprise electron deficient alkenes.

58. The resin blend of claim 57 wherein said electron deficient alkenes independently are selected from the group consisting of substituted and unsubstituted alkenyl ester groups comprising a polymerizable unsaturated carbon—

carbon bond, wherein said alkenyl group has from about 2 to about 12 carbon atoms.

59. The resin blend of claim 55 wherein said polymerizable groups are acryloyl groups and methacryloyl groups.

60. The resin blend of claim 58 wherein R² is selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups.

61. The resin blend of claim 58 wherein R² is a t-butyl group.

62. The resin blend of claim 59 wherein R² is selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups.

63. The resin blend of claim 59 wherein R² is a t-butyl group.

64. The resin blend of claim 59 wherein A comprises from about 2 to about 10 carbon atoms.

65. The resin blend of claim 59 wherein A comprises from about 2 to about 6 carbon atoms.

66. The resin blend of claim 62 wherein A comprises from about 2 to about 10 carbon atoms.

67. The resin blend of claim 62 wherein A comprises from about 2 to about 6 carbon atoms.

68. The resin blend of claim 63 wherein A has 6 carbon atoms.

69. The resin blend of claims 60 wherein said secondary monomer is 2-(t-butyl), 1-[4-(6-acrytoxy-hexyl-1-oxy)-benzoyloxy], 4-[4-{6-(3-acryl oxy-propionoxy)-hexyl-1-oxy}-benzoyloxy]-benzene.

70. The resin blend of claims 68 wherein said secondary monomer is 2-(t-butyl), 1-[4-(6-acryloxy-hexyl-1-oxy)-benzoyloxy], 4-[4-{6-(3-acryl oxy-propionoxy)-hexyl-1-oxy}-benzoyloxy]-benzene.

71. The resin blend of any of claims 46 wherein said secondary monomer has the following general structure:

72. The resin blend of claim 71 wherein both of said R⁵ and R⁹ are secondary polymerizable groups.

73. The resin blend of claim 71 wherein said secondary polymerizable groups are nucleophiles selected from the group consisting of an ester group, an organic acid group, an amine group, a hydroxyl group, and a sulfhydryl group.

74. The resin blend of claim 71 wherein said secondary polymerizable groups comprise electron deficient alkenes.

75. The resin blend of claim 74 wherein said electron deficient alkenes independently are selected from the group consisting of substituted and unsubstituted alkenyl ester groups comprising a polymerizable unsaturated carbon—

carbon bond, wherein said alkenyl group has from about 2 to about 12 carbon atoms.

76. The resin blend of claim 71 wherein said secondary polymerizable groups are selected from the group consisting of acryloyl groups and methacryloyl groups.

77. The resin blend of claim 71 wherein R⁷ is selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups.

78. The resin blend of claim 71 wherein R⁷ is selected from the group consisting of t-butyl groups and phenyl groups.

79. The resin blend of claim 71 wherein X, Y and Z independently comprises from about 2 to about 10 carbon atoms.

80. The resin blend of claim 71 wherein X, Y, and Z independently comprises from about 2 to about 6 carbon atoms.

81. The resin blend of claim 71 wherein X, Y, and Z have 6 carbon atoms.

82. The resin blend of claims 66 wherein said secondary monomer is α

,ω

-bis-4-[4-{4-(ω

-R-acryloxy-alkyloxy)-benzoyloxy}-2-R⁷-phenoxy carbonyl]-phenoxy-R¹³ wherein;

said alkyls have from about 2 to about 12 carbon atoms; and

R is selected from the group consisting of H and CH₃;

R⁷ independently is selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups;

and R¹³ is selected from the group consisting of hydrogen and a methyl group.

83. The resin blend of claim 82 wherein R⁷ independently is selected from the group consisting of t-butyl groups and phenyl groups.

84. The resin blend of claim 82 wherein R⁷ is a t-butyl group.

85. The resin blend of claim 84 wherein said alkyls of said secondary monomer have from about 2 to about 10 carbon atoms.

86. The resin blend of claim 84 wherein said alkyls of said secondary monomer have from about 2 to about 6 carbon atoms.

87. The resin blend of claim 84 wherein said alkyls of said secondary monomer have 6 carbon atoms.

88. The resin blend of claim 66 wherein said secondary monomer has the following general structure:

89. The resin blend of claim 88 wherein n and m are selected from the group consisting of from about 4 to about 11.

90. The resin blend of claim 66 wherein said secondary monomer is a composition having the following general structure:

91. The resin blend of any of claims 66 wherein said secondary monomer is n-[4-({n-[(2-(R⁷)-4-{4-[n-(2-R-prop-2-noyloxy)alkyloxy]phenylcarbonyl oxy}phenyl)oxycarbonyl]alkyl}oxycarbonyl)phenoxy]alkyl 2-R-prop-2-enoate wherein:

R is selected from the group consisting of hydrogen and a methyl group; and

said alkyls have from about 2 to about 12 carbon atoms; and

R⁷ is selected from the group consisting of a t-butyl group, a phenyl group, an isopropyl group, and a secondary butyl group.

92. The resin blend of claim 91 wherein R⁷ is selected from the group consisting of a t-butyl group and a phenyl group.

93. The resin blend of claim 91 wherein R⁷ is a t-butyl group.

94. The resin blend of claim 91 wherein said alkyls of said secondary monomer have from about 2 to about 10 carbon atoms.

95. The resin blend of claim 92 wherein said alkyls of said secondary monomer have from about 2 to about 6 carbon atoms.

96. The resin blend of claim 93 wherein said alkyls of said secondary monomer have 6 carbon atoms.

97. The resin blend of claim 66 wherein said secondary monomer has the following general structure:

98. The resin blend of claim 97 wherein n and m independently are selected from the group consisting of from about 2 to about 10.

99. The resin blend of claim 97 wherein n and m independently are selected from the group consisting of from about 2 to about 6.

100. The resin blend of claim 97 wherein n and m are 6.

101. The resin blend of claim 66 wherein said secondary monomer has the following general structure:

102. The resin blend of claim 66 wherein said secondary monomer has the following general structure:

103. The resin blend of claim 66 wherein said secondary monomer is nonanedioic acid-α

,ω

-bis-(2-R⁷)-4-[4-{6-(2-R-acryloyloxy)-alkyloxy}-benzoyloxy]- phenyl ester wherein;

said alkyl has from about 2 to about 12 carbon atoms; and

R⁷ is selected from the group consisting of a t-butyl group, a phenyl group, an isopropyl group, and a secondary butyl groups; and

R is selected from the group consisting of H and CH₃.

104. The resin blend of claim 103 wherein R⁷ is selected from the group consisting of a t-butyl group and a phenyl group.

105. The resin blend of claim 103 wherein R⁷ is a t-butyl group.

106. The resin blend of claim 103 wherein said alkyl of said secondary monomer has from about 2 to about 10 carbon atoms.

107. The resin blend of claim 103 wherein said alkyl of said secondary monomer has from about 2 to about 6 carbon atoms.

108. The resin blend of claim 103 wherein said alkyl of said secondary monomer has 6 carbon atoms.

173. The composition of claim 46 comprising a dental restorative material.

174. The composition of claim 46 comprising a precursor to an optical device.

176. The composition of claims 46 comprising an adhesive.

177. Optical devices comprising a composite formed using the resin blend of claims 46.

178. A composition for making optical devices comprising the resin blend of claim 46.

179. A bone restoration comprising a composite formed from the resin blend of claim 46.

180. A dental restoration comprising a composite formed from the resin blend of claims 46.

109. A composition having the following general structure:

110. The composition of claim 109 wherein both of said R⁵ and R⁹ are polymerizable groups.

111. The composition of claims 109 wherein said polymerizable group is a nucleophile selected from the group consisting of an ester group, an organic acid group, an amine group, a hydroxyl group, and a sulfhydryl group.

112. The composition of claim 109 wherein said polymerizable group comprises an electron deficient alkene.

113. The composition of claim 112 wherein said electron deficient alkene independently is selected from the group consisting of substituted and unsubstituted alkenyl ester groups comprising a polymerizable unsaturated carbon-carbon bond, wherein said alkenyl group has from about 2 to about 12 carbon atoms.

114. The composition of claim 112 wherein said polymerizable groups are acryloyl groups and methacryloyl groups.

115. The composition of claim 109 wherein R⁷ is selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups.

116. The composition of claim 113 wherein R⁷ is selected from the group consisting of t-butyl groups and phenyl groups.

117. The composition of claim 109 wherein X, Y and Z independently comprises from about 2 to about 10 carbon atoms.

118. The composition of claim 115 wherein X, Y, and Z independently comprises from about 2 to about 6 carbon atoms.

119. The composition of claim 116 wherein X, Y, and Z have 6 carbon atoms.

120. A composition having the following general structure:

121. The composition of claim 120 wherein n and m are selected from the group consisting of from about 4 to about 11.

122. The composition α

,ω

-bis-4-[4-{4-(ω

-R-acryloxy-alkyloxy)-benzoyloxy}-2-R⁷-phenoxy carbonyl]-phenoxy-alkane wherein;

R is selected from the group consisting of H and CH₃.

said alkyls have from about 2 to about 12 carbon atoms; and

R⁷ independently is selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups.

123. The composition of claim 122 wherein R⁷ independently is selected from the group consisting of t-butyl groups and phenyl groups.

124. The composition of claim 122 wherein R⁷ is a t-butyl group.

125. The composition of claim 122 wherein said alkyls have from about 2 to about 10 carbon atoms.

126. The composition of claim 122 wherein said alkyls have from about 2 to about 6 carbon atoms.

127. The composition of claim 123 wherein said alkyls have 6 carbon atoms.

128. A composition having the following general structure:

129. The compound n-[4-({n-[(2-(R⁷)-4-{4-[n-(2-R-prop-2-noyloxy)alkyloxy]phenylcarbonyloxy}phenyl)oxycarbonyl]alkyl}oxycarbonyl)phenoxy]alkyl 2-R-prop-2-enoate wherein:

R is selected from the group consisting of H and CH₃,

said alkyls have from about 2 to about 12 carbon atoms; and

R⁷ is selected from the group consisting of a t-butyl group, a phenyl group, an isopropyl group, and a secondary butyl group.

130. The composition of claim 129 wherein R⁷ is selected from the group consisting of a t-butyl group and a phenyl group.

131. The composition of claim 129 wherein R⁷ is a t-butyl group.

132. The composition of claim 129 wherein said alkyls have from about 2 to about 10 carbon atoms.

133. The composition of claim 130 wherein said alkyls have from about 2 to about 6 carbon atoms.

134. The composition of claims 131 wherein said alkyls have 6 carbon atoms.

135. A composition having the following general structure:

136. The composition of claim 135 wherein n and m independently are selected from the group consisting of from about 2 to about 10.

137. The composition of claim 135 wherein n and m independently are selected from the group consisting of from about 2 to about 6.

138. The composition of claim 135 wherein n and m are 6.

139. A composition having the following general structure:

140. A composition having the following general structure:

141. A composition having the following general structure:

142. The composition nonanedioic acid bis-(2-R⁷-4-{4-[6-(2-R-acryloyloxy)-alkyloxy]-benzoyloxy}-phenyl) ester wherein:

R is selected from the group consisting of H and CH₃;

said alkyls have from about 2 to about 12 carbon atoms; and

R⁷ is selected from the group consisting of a t-butyl group, a phenyl group, an isopropyl group, and a secondary butyl groups.

145. The composition of claims 142 wherein said alkyl has from about 2 to about 10 carbon atoms.

143. The composition of claim 143 wherein R⁷ is selected from the group consisting of a t-butyl group and a phenyl group.

144. The composition of claim 143 wherein R⁷ is a t-butyl group.

146. The composition of claims 143 wherein said alkyl has from about 2 to about 6 carbon atoms.

147. The composition of claim 144 wherein said alkyl has 6 carbon atoms.

148. A method for making a composition comprising

providing a 4-hydroxyl benzoic acid comprising a carboxyl substituent;

providing an alkylene group comprising an α

-halide group and an ω

-halide group;

condensing said 4-hydroxyl of said benzoic acid with said ω

-halide group under first conditions effective to activate said carboxyl substituent and to produce a hydroxyl terminated alkyloxy comprising said α

-hydroxyl group at a first terminus and an activated carboxyl substituent of said 4-hydroxyl benzoic acid at a second terminus;

providing a hydroquinone comprising a bulky organic group and comprising a first hydroxyl group para- to a second hydroxyl group, at least one of said first hydroxyl group and said second hydroxyl group being an ionically activated hydroxyl group;

condensing said activated carboxyl substituent with said at least one ionically activated hydroxyl group of said hydroquinone under second conditions effective to produce α

,ω

-bis-4-[4-{4-(ω

-R-acryloxy-alkyloxy)-benzoyloxy}-2-R⁷-phenoxy carbonyl]-phenoxy-alkane.

149. A method for making a composition comprising

providing a 4-hydroxyl benzoic acid comprising a carboxyl substituent;

providing an alkylene group comprising an α

-halide group and an ω

-halide group and comprising from about 2 to about 12 carbon atoms;

condensing said 4-hydroxyl of said benzoic acid with said ω

-halide group under first conditions effective to activate said carboxyl substituent and to produce a hydroxyl terminated alkyloxy comprising said α

-hydroxyl group at a first terminus and an activated carboxyl substituent of said 4-hydroxyl benzoic acid at a second terminus;

providing a 2-(R⁷)-4-[4-(6-acryloxy-alkyloxy)-benzoyloxy]-phenol comprising a bulky organic group and an ionically activated hydroxyl group para- to said [4-(6-acryloxy-alkyloxy)-benzoyloxy] group;

condensing said activated carboxyl substituent with said ionically activated hydroxyl group under second conditions effective to produce nonanedioic acid-α

,ω

-bis-(2-R⁷)-4-[4-{ω

-(2-R-acryloyloxy)-alkyloxy}-benzoyloxy]-phenyl ester.

150. The method of claim 149 wherein said bulky organic group is selected from the group consisting of t-butyl groups, phenyl groups, isopropyl groups, and secondary butyl groups.

151. The method of claim 149 wherein said bulky organic group is selected from the group consisting of t-butyl groups and phenyl groups.

152. The method of claim 149 wherein said bulky organic group is a t-butyl group.

153. The method of claims 150 wherein said alkyl has from about 2 to about 6 carbon atoms.

154. The method of claims 151 wherein said alkyl is hexyl.

155. A method for making a composition comprising

providing a 4-hydroxyl benzoic acid comprising a carboxyl substituent;

providing an alkanoyl halide comprising an ω

-halide group and having from about 2 to about 12 carbon atoms;

condensing said 4-hydroxyl of said benzoic acid with said ω

-halide group under first conditions effective to activate said carboxyl substituent and to produce 4-(ω

-R-acryloxy-alkyloxy) benzoic acid comprising an activated carboxyl substitutent;

providing a hydroquinone comprising a bulky organic group and comprising a first hydroxyl group para- to a second hydroxyl group, at least one of said first hydroxyl group and said second hydroxyl group being an ionically activated hydroxyl group;

condensing said activated carboxyl substituent of said 4-(ω

-R-acryloxy-alkyloxy) benzoic acid with with said at least one ionically activated hydroxyl group of said hydroquinone under second conditions effective to produce 2-(R⁷)-1-[4-(ω

-R-acryloxy-alkyl-α

-oxy)-benzoyloxy], 4-(ω

-halo-α

-alkanoyloxy)-benzene.

156. The method of claim 155 wherein said alkanoyl halide comprises from about 2 to about 10 carbon atoms.

157. The method of claim 155 wherein said alkanoyl halide comprises from about 2 to about 6 carbon atoms.

158. The method of claim 155 wherein said alkanoyl halide has 6 carbon atoms.

159. The method of claim 155 wherein said ω

-halide group is chlorine.

160. The method of claim 155 wherein

said first conditions comprise the presence of an acid halogenating agent;

and,

said second conditions comprise the presence of an ionic activating agent for at least one of said first and said second hydroxyl groups.

161. A resin blend comprising a liquid crystal monomer at a 3:

2 ratio to a secondary monomer said secondary monomer being 2-(t-butyl),1-[4-(6-acryloxy-hexyl-1-oxy)-benzoyloxy], 4-[4-{6-(3-acryl oxy-propionoxy)-hexyl-1-oxy}-benzoyloxy]-benzene, said liquid crystal monomer having the following general structure;

162. A resin blend comprising an inorganic filler and a liquid crystal monomer at a ratio of 3:

2 to a secondary monomer said secondary monomer being 2-(t-butyl), 1-[4-(6-acryloxy-hexyl-1-oxy)-benzoyloxy], 4-[4-{6-(3-acryl oxy-propionoxy)-hexyl-1-oxy}-benzoyloxy]-benzene, said liquid crystal monomer having the following general structure;

163. A resin blend comprising an inorganic filler and a liquid crystal monomer at a 3:

2 ratio to a secondary monomer, said secondary monomer being 2-(t-butyl), 1-[4-(6-acryloxy-hexyl-1-oxy)-benzoyloxy], 4-[4-{6-(3-acryl oxy-propionoxy)-hexyl-1-oxy}-benzoyloxy]-benzene, said liquid crystal monomer having the following general structure;

164. A resin blend comprising an inorganic filler and a liquid crystal monomer at a ratio of 3:

2 to a secondary monomer, said secondary monomer being 2-(t-butyl), 1-[4-(6-acryloxy-hexyl-1-oxy)-benzoyloxy], 4-[4-{6-(3-acryl oxy-propionoxy)-hexyl-1-oxy}-benzoyloxy]-benzene, and said liquid crystal monomer has the following general structure;

165. A resin blend comprising an inorganic filler and a liquid crystal monomer at a ratio to a secondary monomer, said secondary monomer and said ratio being adapted to produce a nematic to isotopic transition temperature for said resin blend of about 50°

C. or more.

166. The blend of claim 165 wherein said nematic to isotopic transition temperature for said blend is about 60°

C. or more.

167. The blend of claim 165 wherein said liquid crystal monomer has the following general structure:

168. The blend of claim 167 wherein said polymerizable groups are acryloyl groups and methacryloyl groups.

169. The blend of claim 168 wherein R² is a t-butyl group.

170. The blend of claim 168 wherein A comprises from about 2 to about 6 carbon atoms.

171. The blend of claim 169 wherein A has 6 carbon atoms.

172. The blend of any of claims 167 wherein said secondary monomer is selected from the group consisting of:

2-(t-butyl), 1-[4-(6-acryloxy-hexyl-1-oxy)-benzoyloxy], 4-[4-{6-(3-acryl oxy-propionoxy)-hexyl-1-oxy}-benzoyloxy]-benzene;

compounds having the following general structure;

wherein

n is selected from the group of 0 and 1;

X and Y independently are selected from the group consisting of linear and branched alkyl groups having from about 2 to about 12 carbon atoms;

Z is selected from the group consisting of linear and branched alkyl groups having from about 2 to about 12 carbon atoms;

provided that, when n is 0, Z is further selected from the group consisting of 2-alkyl-1,4-bis[-4-(alkyl-6-yl-1-oxo)-benzoyloxy]-benzene and, when n is 1, Z is further selected from the group consisting of 4-oxoalkyl-benzoyl groups, wherein said alkyl groups independently have from about 2 to about 12 carbon atoms;

R⁷ is a bulky organic group having a bulk greater than R₁ and R₃, said bulk being adapted to provide sufficient steric hindrance for said liquid crystal monomer to achieve a nematic state at room temperature while suppressing crystallization of said blend at 20°

C.;

R⁶ and R⁸ are selected from the group consisting of hydrogen atoms and methyl groups;

R⁵ and R⁹ are polymerizable groups selected from the group consisting of nucleophiles and groups comprising an electron deficient alkene.

compounds having the following general structure;

wherein

R is selected from the group consisting of hydrogen and a methyl group; and

n and m independently are selected from the group consisting of from about 2 to about 11.

compounds having the following general structure;

2-(R⁷)-1-[4-(ω

-substituted acryloxy-alkyl-α

-oxy)-benzoyloxy], 4-[ω

-{4-(ω

′

-substituted acryloxy-alkyl-α

-oxy)-benzoyloxy}-α

-alkyloyloxy]-benzene wherein;

R is selected from the group consisting of H and CH₃;

said alkyls have from about 2 to about 12 carbon atoms; and

R7 is selected from the group consisting of a t-butyl group, a phenyl group, an isopropyl group, and a secondary butyl group.

compounds having the following general structure;

wherein

n and m independently are selected from the group consisting of from about 2 to about 12; and

R is selected from the group consisting of H and CH₃.

compounds having the following general structure;

compounds having the following general structure;

compounds having the following general structure;

2 nonanedioic acid-α

,ω

-bis-(2-R⁷)-4-[4-{6-(2-R-acryloyloxy)-alkyloxy}-benzoyloxy]-phenyl ester wherein;

R is selected from the group consisting of H and CH₃;

said alkyl has from about 2 to about 12 carbon atoms; and

R⁷ is selected from the group consisting of a t-butyl group, a phenyl group, an isopropyl group, and a secondary butyl groups.

181. A method for delaying crystallization of a primary liquid crystal monomer which otherwise crystallizes in under 30 minutes after addition of inorganic filler at a temperature of 20°

C., said method comprising providing a resin blend comprising said primary liquid crystal monomer and at least one secondary monomer, whereby upon addition of said inorganic filler to said resin blend at a temperature of 20°

C., said resin blend maintains a nematic liquid crystallin state for about 30 minutes or more and exhibits about 4 vol. % or less polymerization shrinkage.