Heat resistance of biobased materials, evaluation and effect of processing techniques and additives

Abstract

The paper describes the effect of different manipulations (addition of fiber, nanoclay, nucleating agents and chain extender, blending, annealing, use of a higher mold temperature and stereocomplexation) on the heat resistance of poly(lactic acid) (PLA) and poly(hydroxybutyrate) (PHB). Therefore, the differential scanning calorimetry profiles, the vicat softening temperatures and the degradation temperatures were measured and compared to standard PLA, PHB, and polypropylene (PP) as reference materials. Furthermore, a comparison between VST and HDT as parameters for heat resistance was made by examining the deformation during contact with hot water. Stereocomplexation and the use of a higher mold temperature seemed the best techniques to obtain PLA‐based materials with good heat resistance, while other manipulations had little to no effect on the processed biopolymer. The addition of chain extender to PLA and PHB had no effect on processed polymers, but it did improve the thermal degradation of PLA during processing. Furthermore, hot fill tests showed that higher VST values were more reliable as a heat resistant parameter than HDT values for these kinds of application. The VST values of PHB were similar to PP, suggesting that PHB also provides opportunities as a packaging material for food products that undergo a heat treatment. POLYM. ENG. SCI., 58:513–520, 2018. © 2017 Society of Plastics Engineers

A novel hollow microsphere acting on crystallization, mechanical, and thermal performance of poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate)

“…In this work, DM was used as NAs of P34HB, and the crystallization behavior was studied in detail via differential scanning calorimetry (DSC) and wide angle X‐ray diffraction (WAXD). Improved thermal resistances were evaluated by Vicat softening point 18,19 . The processing behaviors were simulated from torque change.…”

Sustainable Materials with Enhanced Mechanical Properties Based on Industrial Polyhydroxyalkanoates Reinforced with Organomodified Sepiolite and Montmorillonite

“…Commercial PHAs purchased for plastic parts production are usually blended with other copolyesters and contain small amounts of plasticisers and metal elements, such as Na + , Ca 2+ and Mg 2+ . These additives have an effect on the crystallisation, thermal stability [25], mechanical properties [26] and biodegradability of the commercial materials. However, this behaviour is not always functional enough for many industrial applications, and the use of other additives or fillers such as fibres [27,28,29] or nanoparticles [30,31] is needed.…”

Crystallization Morphology Regulation on Enhancing Heat Resistance of Polylactic Acid

“…Polylactic acid (PLA) has attracted considerable research interest owing to its good biocompatibility and biodegradability [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. However, its disadvantages, such as poor heat-deflection temperature (HDT: 50 °C for neat PLA) and slow crystallization rate, limit its application [ 8 , 9 , 10 , 11 , 12 , 13 ]. HDT is a crucial physical quantity used to characterize the heat resistance of polymeric materials [ 14 , 15 ].…”