Crystallization Morphology Regulation on Enhancing Heat Resistance of Polylactic Acid

Abstract

To expand the use of polylactic acid (PLA) in high-temperature environments, crystallization morphology regulation was studied to enhance the heat resistance of PLA. PLA crystallinity was controlled using heat treatment and nucleating agent (zinc phenylphosphonate, brand TMC). The heat deflection temperatures of PLAs with same crystallinities considerably varied using different treatments. The crystallization morphology of PLA (4032D) and PLA/TMC composites was studied using X-ray diffraction (XRD) and polarized optical microscopy. XRD test results show that TMC can improve the crystallization rate and heat treatment can enhance the crystallinity and thickness of PLA, suggesting that the crystallization morphology improved after heat treatment. Nucleating agents can increase the crystallinity of PLA but cannot improve its crystallization morphology. The findings indicate that at the same crystallinity, PLAs exhibit improved crystallization morphology and high heat resistance; these results can provide guidance for improving the heat resistance of PLAs and facilitate the design of new nucleating agents.

Polymer Crystallization on One-Dimensional Templates: From a Hybrid Shish-Kebab-like Structure to Material Properties

“…Self-assembling NAs have also been used to accelerate the crystallization kinetics and tune the crystalline morphology of PLLA and PLLA/PDLA blends. Until now, several kinds of self-assembling NAs have been reported to accelerate the crystallization of PLLA and PLLA/PDLA blends, which includes amide compounds (e.g., EBH, TMC-328, , BTCA, OXA1, and OXA2), hydrazide compounds (e.g., TMC-300, TMC-306, OMBH, and TMBH), and organic salt compounds (e.g., TMC-210). As a typical example, the crystal morphology of PLLA/TMC-328 blends with different contents of TMC-328 was investigated by Fu et al, which sequentially shows macroscopic cone-like, needle-like structures, and finally a typical SK-like superstructure with the increase of NAs content.…”

Modification of Poly(lactic acid) by the Plasticization for Application in the Packaging Industry

“…Poly(lactic acid) (PLA), belonging to the group of biodegradable polymers obtained from biomass, is currently of great interest in the packaging industry [16][17][18][19]. PLA has good mechanical properties compared to traditional polymers [20][21][22][23][24].…”

Tailoring the performance of poly(lactic acid)‐based reactive blends: The effect of vinyl acetate and dicumyl peroxide content

“…The HDT, VST, and Shore D hardness results of the studied materials are illustrated in Figure 13a–c, respectively. PLA has the disadvantage of low thermomechanical stability, 70,71 with an HDT of around 53.7°C and a VST of 57°C. After the addition of EVA to the PLA matrix, in the case of a material with elastomeric characteristics, there was a slight decay in the HDT and VST of the materials.…”

“…[67][68][69] The HDT, VST, and Shore D hardness results of the studied materials are illustrated in Figure 13a-c, respectively. PLA has the disadvantage of low thermomechanical stability, 70,71 with an HDT of around 53.7 C and a VST of 57 C. After the addition of EVA to the PLA matrix, in the case of a material with elastomeric characteristics, there was a slight decay in the HDT and VST of the materials. For blends crosslinked with DCP, there is a decrease in HDT, both for PLA/EVA blends and for PLA with the addition of DCP, remaining around 51-53 C. For the VST, for the dynamically vulcanized systems, compared with the binary blends and the pure PLA, there was maintenance, taking into account the experimental error (standard deviation).…”