The effects of catalyst on the molecular weight, chemical structure, and yellowness of isosorbide-based polycarbonate (ISB-PC) in the melt-transesterification and polycondensation stages were investigated. Results showed that the high steric hindrance and intramolecular hydrogen bonding of the endohydroxyl group (endo−OH) of ISB enabled its reactivity to be lower than that of the exohydroxyl group (exo−OH). We also found that the reactivity of endo− OH with diphenyl carbonate can be preferentially activated by strong electrophilic catalysts, and that the configuration of the ISB-PC chain strongly depended on the reactivity balance between endo−OH and exo−OH. Various catalysts with different coordinate capacities, acidity coefficients, and radius of metal ion were further tested. Catalysts with a calcium or zinc ion showed a higher reactivity of endo−OH than exo−OH, resulting in a high glass-transition temperature of ISB-PCs. Results suggested as well that the thermal stability of ISB-PC may be correlated to the amount of OH groups at the chain ends, whereas its yellowness mainly arose from 1,4-sorbitan due to the hydrolysis of ISB.

In this study, poly (lactic acid) (PLA) blended with various rubber components, i.e., poly (ethylene‐glycidyl methacrylate) (EGMA), maleic anhydride grafted poly(styrene‐ethylene/butylene‐styrene) triblock elastomer (m‐SEBS), and poly(ethylene‐co‐octene) (EOR), was investigated. It was observed that EGMA is highly compatible due to its reaction with PLA. m‐SEBS is less compatible with PLA and EOR is incompatible with PLA. Electron microscopy (SEM and TEM) revealed that a fine co‐continuous microlayer structure is formed in the injection‐molded PLA/EGMA blends. This leads to polymer blends with high toughness and very low linear thermal expansion both in the flow direction and in the transverse direction. The microlayer thickness of rubber in PLA blends was found to play key roles in reducing the linear thermal expansion and achieving high toughness of the blends. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Isosorbide polycarbonate (ISB-PC) was prepared by melt transesterification and polycondensation reaction by employing ISB and diphenyl carbonate (DPC) as monomers.

No abstract

No abstract

No abstract

Short-fiber-reinforced rubber composites (SFRCs) with hydrogenated acrylonitrile butadiene rubber (HNBR) as the matrix and fibrillar silicate (FS) nanofibers and short aramid microfibers (DCAFs) as the fillers were developed, and their tensile properties, compression moduli, and mechanical anisotropies were investigated. The results indicated that the properties of the HNBR/DCAF/ FS composites were determined by the loadings of the FS nanofibers and DCAF microfibers. A small amount of the microfibers combined with an appropriate amount of the nanofibers resulted in synergetic reinforcement and imparted to the SFRCs significantly improved mechanical properties without substantially compromising the rubbery characteristics.

No abstract