High molecular weight poly(2,6-dimethyl-1,4-phenylene ether) and process therefor

• US 8,215,495 B2
• Filed: 08/08/2011
• Issued: 07/10/2012
• Est. Priority Date: 02/21/2008
• Status: Active Grant

• Current Assignee: SHPP Global Technologies BV
• Original Assignee: Sabic Innovative Plastics IP BV (Government of Saudi Arabia)
• Inventors: Delsman, Erik Rene, Schoenmakers, Gert-Jan
• Primary Examiner(s): Truong, Duc
• Application Number:
  US13/205,117
• Publication Number:
  US 20110288262A1
• Time in Patent Office: 337 Days
• Field of Search: 210/500.23, 528/86, 528/486, 528/492, 528/497, 528/502.D, 528/503, 524/434
• US Class Current: 210/500.23
• CPC Class Codes: C08G 65/4093 characterised by the process or apparatus used
• CPC Class Codes: C08G 65/44 by oxidation of phenols
• CPC Class Codes: C08G 65/485 Polyphenylene oxides
• CPC Class Codes: Y10T 428/2975 Tubular or cellular

Abstract

A poly(2,6-dimethyl-1,4-phenylene ether) having a high molecular weight and a reduced content of low molecular weight species can be prepared by a method that includes specific conditions for the oxidative polymerization, chelation, and isolation steps. The poly(2,6-dimethyl-1,4-phenylene ether) is particularly useful for the fabrication of fluid separation membranes.

Claims

1. A poly(2,6-dimethyl-1,4-phenylene ether) made by a method comprising

oxidatively polymerizing 2,6-dimethylphenol in toluene solvent in the presence of a catalyst comprising copper ion, N,N′

-di-tert-butylethylenediamine, dimethyl-n-butylamine, and di-n-butylamine to form a reaction mixture comprising a dissolved poly(2,6-dimethyl-1,4-phenylene ether), water, and the catalyst;

wherein the oxidative polymerizing comprises initiating oxidative polymerization in the presence of 1 to 3 weight percent of the 2,6-dimethylphenol;

wherein at least 97 weight percent of the 2,6-dimethylphenol is added to the reaction mixture after the initiation of oxidative polymerization and over the course of 55 to 65 minutes;

wherein the oxidatively polymerizing comprises adding molecular oxygen and 2,6-dimethylphenol to the reaction mixture in a mole ratio of 0.3;

1 to 0.5;

1;

wherein the oxidatively polymerizing 2,6-dimethylphenol comprises a first stage in which the reaction mixture is cooled to maintain a temperature of 20 to 30°

C., and a second stage in which the reaction mixture is heated to maintain a temperature of 30 to 40°

C.;

terminating the oxidative polymerization to form a post-termination reaction mixture;

combining a chelant comprising an alkali metal salt of nitrilotriacetic acid with the post-termination reaction mixture to form a chelation mixture comprising

an aqueous phase comprising chelated copper ion, and

an organic phase comprising the dissolved poly(2,6-dimethyl-1,4-phenylene ether);

wherein the chelation mixture excludes dihydric phenols and aromatic amines;

maintaining the chelation mixture at a temperature of 45 to 55°

C. for 40 to 70 minutes;

separating the aqueous phase and the organic phase;

wherein the separation is conducted at a temperature of 45 to 55°

C.;

isolating the poly(2,6-dimethyl-1,4-phenylene ether) from the separated organic phase;

wherein time elapsed between termination of the oxidative polymerization and isolating the poly(2,6-dimethyl-1,4-phenylene ether) is 30 to 60 minutes;

wherein the method excludes a solvent removal step between the terminating the oxidative polymerization and the isolating the poly(2,6-dimethyl-1,4-phenylene ether);

wherein the isolated poly(2,6-dimethyl-1,4-phenylene ether) has a number average molecular weight of 20,000 to 35,000 atomic mass units and 16 to 20 weight percent of molecules having a molecular weight less than 30,000 atomic mass units; and

wherein the isolated poly(2,6-dimethyl-1,4-phenylene ether) has a copper concentration of 0.5 to 5 parts per million by weight.

2. A fiber comprising the poly(2,6-dimethyl-1,4-phenylene ether) of claim 1.

3. An article comprising the poly(2,6-dimethyl-1,4-phenylene ether) of claim 1.