Partially crosslinked silalactone polymers, their preparation and their use

• US 3,948,864 A
• Filed: 06/12/1974
• Issued: 04/06/1976
• Est. Priority Date: 06/13/1973
• Status: Expired due to Term

• Current Assignee: Rhone-Poulenc S.A. (Sanofi )
• Original Assignee: Rhone-Poulenc S.A. (Sanofi )
• Inventors: Bargain, Michel, Pasquini, Zeno
• Primary Examiner(s): Czaja, Donald E.
• Assistant Examiner(s): Nielsen, Earl A.
• Application Number:
  US05/478,604
• Time in Patent Office: 664 Days
• Field of Search: 260/78.3 R, 260/448.2 B, 204/159.13
• US Class Current: 528/41
• CPC Class Codes: C08G 63/6952 derived from hydroxycarboxylic acids
• CPC Class Codes: C08G 63/912 derived from hydroxycarboxylic acids

Abstract

Linear homopolymers of 3,5,5-trimethyl-1-oxa-5-sila-cyclohexan-2-one are crosslinked through the 5-methyl group, e.g. by heating with an organic peroxide, to give polymers. Films of these cross linked polymers have a critical surface tension similar to teflon and can be used for water proofing. The films also exhibit selective permeability to gases and can be used to reduce the CO₂ content of CO₂ /O₂ mixtures.

Claims

1. A 3,5,5-trimethyl-1-oxa-5-sila-cyclohexan-2-one polymer having repeat units of formula I ##EQU5## at least some of the units being crosslinked to one another.

2. A polymer according to claim 1 consisting essentially of repeat units of formula I, of formula II and of formula III ##EQU6## in which the 5-methylene --CH₂ --group(s) in unit II and unit III is directly bonded to a 5-methylene --CH₂ --group(s) in another unit II or unit III and each oxygen atom in a repeat unit is bonded to a CO group in another repeat unit.

3. A polymer according to claim 1 in which the carboxylic chain end is blocked with a blocking group for carboxylic groups and the hydroxy chain end is blocked with a blocking group for hydroxy groups.

4. A process for the preparation of a 3,5,5-trimethyl-1-oxa-5-sila-cyclohexan-2-one polymer as defined in claim 1 wherein a linear 3,5,5-trimethyl-1-oxa-5-sila-cyclohexan-2-one homopolymer is partially crosslinked.

5. A process according to claim 4 wherein the carboxylic chain end of the linear 3,5,5-trimethyl-1-oxa-5-sila-cyclohexan-2-one polymer is blocked with a blocking agent for carboxylic groups and the hydroxy chain end of the linear polymer is blocked with a blocking agent for hydroxy groups.

6. A process according to claim 4 wherein the crosslinking is effected by heating the polymer with a peroxide.

7. A process according to claim 6 wherein 1-20 mols of peroxide is used per 100 monomer units present in the linear 3,5,5-trimethyl-1-oxa-5-sila-cyclohexan-2-one polymer.

8. A process according to claim 4 wherein the crosslinking is effected by irradiating the linear polymer.

9. A membrane having selective permeability to gases comprising a crosslinked 3,5,5-trimethyl-1-oxa-5-sila-cyclohexan-2-one polymer according to claim 1.