AGING PHENOMENA IN BACTERIAL POLY[(R)-3-HYDROXYBUTYRATE] .1. A STUDY ON THE MOBILITY IN POLY[(R)-3-HYDROXYBUTYRATE] POWDERS BY MONITORING THE RADICAL DECAY WITH TEMPERATURE AFTER GAMMA-RADIOLYSIS AT 77-K

POLYMER

卷:33

Note

DEKONING, GJM ; LEMSTRA, PJ ; HILL, DJT ; CARSWELL, TG ; ODONNELL, JH

关键词: POLY[(R)-3-HYDROXYBUTYRATE];    PHB;    PHYSICAL AGING;    GAMMA-IRRADIATION;    ESR;    SEGMENTAL MOBILITY;   

DOI  :  10.1016/0032-3861(92)90250-Z

来源: Elsevier

【 摘 要 】

Poly[(R)-3-hydroxybutyrate] (PHB), a bacterial polyester, is subject to a detrimental ageing process, which hampers its application possibilities. This ageing phenomenon is usually studied using moulded specimens, and was found to be related to a loss in segmental mobility. The presence of additives and orientation in moulded PHB samples might influence this ageing process. As a reference for our ageing studies, we therefore conducted a study on the ageing effects in virgin PHB powder. For this purpose a method is required to measure the mobility in a powder without the employment of heat or mechanical strain, since these are known to induce deageing. This paper describes a suitable technique based on the principle that the variation of the radical concentration with temperature after gamma-irradiation at 77 K provides a measure of the changes in the segmental mobility of the polymer chains.

【 授权许可】

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