Phenolphthalein-modified polyarylene ether nitrile copolymers were synthesized by nucleophilic substitution reaction of 2,6-difluorobenzonitrile (DFBN) with varying molar ratios of phenolphthalein (PP) and hydroquinone (HQ). The copolymers were chemically and physically characterized to have good thermal and mechanical properties. PP content of the copolymers has influence on glass transition temperature (Tg) as well as decomposition temperature (Tid). Coats–Redfern method was applied to study the thermal decomposition kinetics of the copolymers to predict the lifespan under thermal aging process of the copolymers, the results show that the lifespan increases with increasing PP content. © 2005 Elsevier B.V. All rights reserved.

Degradable polyesteramide fibres were processed by melt-spinning. Tensile properties of as-spun and hot-drawn fibres were also investigated. After drawing, the overall crystallinity and the melting temperature of the copolymer increased. As a result, the tensile strength of the fibre increased, and the elongation at break decreased. The morphology of the surface and fracture cross section were studied by SEM. During alkaline degradation, the tensile strength and the elongation at break both decreased.

Titania-containing Polyarylene ether nitriles (PEN) hybrid films have been successfully fabricated via in-situ sol-gel process, nanosized TiO2 particles are found well dispersed within the polymer matrix. The dielectric properties of the films were measured to find that dielectric constant as well as dielectric loss of the hybrid films increased linearly with the increasing TiO2 content without sacrificing dielectric breakdown strength compared to that of the pristine polymer. Increased gel temperature reduced dielectric loss efficiently but has little influence on dielectric constant.

A new type of biodegradable polyesteramide P(LA/AU) based on lactic acid and aminoundecanoic acid was synthesized by the melt polycondensation method. The copolymers obtained were characterized by FTIR. 1H-NMR. DSC. and XRD。 The in vitro degradation behavior of the copolymers was strdied using weighing. H-NMR, FTIR. DSC, and SEM. With the increase in aminoundecanoic acid units, the milting temperature and units, the melting temperature and crystallinity increased, but the water absorption and degradation rate decreased accordingly. During degradation in vitro, the ester mority decreased due to ester cleavage along the macromolecular main chain. As degradation proceeded, the melting temperature and crystallinity increased at first, then started to decrease because the crystalline phase was destroyed.

Hydrolytically degradable PET/PEG block copolymer was synthesized by the macromolecular transesterification method from PET and PEG. Non-isothermal crystallization behavior of the copolymers was investigated by differential scanning calorimetry (DSC). Water absorption and in vitro degradation behaviour of these copolymers were studied in detail. When hydrophilic PEG was incorporated into the PET chain, water absorption increased. With the increase in PEG concentration, the degradation rate increased accordingly. PEG molecular weight has different effects on PET/PEG copolymers’ degradation rate. © 2003 Elsevier Ltd. All rights reserved.