Effect of copolymer composition on free volume and gas permeability in poly(ethylene terephthalate)-poly(1,4 cyclohexylenedimethylene terephthalate) copolyesters

被引：67

作者：

Hill, AJ ^{[1
]}

Weinhold, S ^{[1
]}

Stack, GM ^{[1
]}

Tant, MR ^{[1
]}

机构：

[1] EASTMAN CHEM CO,RES LABS,KINGSPORT,TN 37662

来源：

EUROPEAN POLYMER JOURNAL | 1996年 / 32卷 / 07期

关键词：

D O I：

10.1016/0014-3057(95)00204-9

中图分类号：

O63 [高分子化学（高聚物）];

学科分类号：

070305 ; 080501 ; 081704 ;

摘要：

The gas permeability and free volume of a series of polyester copolymers were studied. The free volume was studied using the positron annihilation lifetime spectroscopy (PALS) technique to indicate the relative size and concentration of free volume cavities in the copolymers. The homopolymers were poly(ethylene terephthalate) (PET) and poly(1,4 cyclohexamethylene terephthalate) (PCT). The copolymers were prepared by reacting terephthalic acid with varying amounts of ethylene glycol and 1,4 cyclohexanedimethanol to produce a copolymer series containing 11.8, 30.8, 31.8, 60.9, 68.9, and 80.8 mol% PCT. The logarithm of the permeability to oxygen and carbon dioxide was found to increase linearly with vol% PCT. The mean free volume cavity size and relative concentration (as indicated by the PALS parameters tau(3) and I-3, respectively) were found to increase approximately linearly with vol% PCT. The results are modelled using the Cohen-Turnbull theory for transport in polymers and discussed in terms of various methods of calculating, from PALS data, the free volume fraction that is important to transport properties. Copyright (C) 1996 Elsevier Science Ltd

引用

页码：843 / 849

页数：7

共 27 条

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