Direct computation of the free volume fraction in amorphous polymers from positron lifetime measurements

被引：43

作者：

Bandzuch, P ^{[1
]}

Kristiak, J ^{[1
]}

Sausa, O ^{[1
]}

Zrubcová, J ^{[1
]}

机构：

[1] SASc, Inst Phys, SK-84228 Bratislava, Slovakia

来源：

PHYSICAL REVIEW B | 2000年 / 61卷 / 13期

关键词：

D O I：

10.1103/PhysRevB.61.8784

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

A model for computation of the free volume fraction from the temperature dependence of positron lifetime is presented. The model is based on the idea that the total free volume of the sample is expanding in the same rate as the volume of holes seen by positrons. Then, having the values of thermal expansion coefficients of bulk and free volume, it is possible to compute the temperature dependence of fraction of free volume f(T) and the thermal expansion coefficient of occupied volume alpha(0). It is also possible to compute the Vogel temperature T-0, WLF coefficient c(2g), and the ratio C-lg/B, where c(lg) is the WLF coefficient and B is the Doolittle constant. The paper also presents computed values of abovementioned parameters for six different polymers. Tn the case of poly(isobutylene) and cia-trans 1,4 poly(butadiene) the results are compared with that obtained from viscosity eta(T) and temperature shift parameter a(T)(T) measurements.

引用

页码：8784 / 8792

页数：9

共 24 条

[1]

Batschinski AJ, 1913, Z PHYS CHEM-STOCH VE, V84, P643

[2]

BECK DL, 1963, SPE TRANS, V3, P279

[3]

Bekkedahl N, 1934, BUR STAND J RES, V13, P411

[4] MOLECULAR TRANSPORT IN LIQUIDS AND GLASSES [J].