摘要:

AbstractThe thermally stimulated current (TSC) technique has been used to perform a detailed study of the complex relaxation modes observed in poly‐L‐proline II. Each mechanism has been resolved into elementary processes, each well described by using the assumption of a single relaxation time following an Arrhenius equation. This resolution allows us to predict the complex dielectric constant for temperatures between 77 and 400°K and frequencies between 10−6and 104Hz. In the range where experimental results are available, the predicted energy losses are in very good agreement with those measured by DC transient experiments, the pendulum technique without contacting electrodes, and the AC bridge. We discuss the probable origin of the various relaxation modes. The relaxation observed at the highest temperature may be attributed to electrons trapped at the boundaries between paracrystalline and crystalline regions. From the changes in the relaxations caused by bound water, we conclude that there are two types of water interacting with the macromolecular substrate. With increasing water content, the relaxation modes observed may first be due to water tightly bound between two carbonyl groups of adjacent chains and second, to increased stiffness of the poly‐L‐proline chain from more mo

ISSN:0098-1273    

DOI:10.1002/pol.1977.180150311

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY

摘要:

AbstractKinetic studies are reported for the light scattering and elasticity of thermally reversible gels of cellulose acetate in benzyl alcohol over a range of temperature and polymer concentration. The small‐angle light scattering data are found to be described by exponential correlation functions, and it is concluded that the scattering has its origin in the nonrandom character of the crosslinking in the gels studied. The elasticity is discussed in terms of the density of crosslinks in the gels. Thus, the kinetics studied by light scattering and elasticity measurements are independently related to temperature and polymer concentratio

ISSN:0098-1273    

DOI:10.1002/pol.1977.180150312

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY

ISSN:0098-1273    

DOI:10.1002/pol.1977.180150313

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY

ISSN:0098-1273    

DOI:10.1002/pol.1977.180150314

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY

ISSN:0098-1273    

DOI:10.1002/pol.1977.180150315

出版商:John Wiley&Sons, Inc.    

年代:1977

数据来源: WILEY