Preparation of Polymer Microparticles Through Non-aqueous Suspension Polycondensations: Part VI—Analyses of Chemical and Enzymatic Degradation of Poly(Butylene Succinate) (PBS)
“…In general, the degradation of the composites in the enzyme buffer can include two forms: enzymatic hydrolysis and hydrolysis. Generally, when the two degradation methods work together, the weight loss in the composites increases [ 32 ]. The highest degradation efficiency of the EMS/PBS composite was 75%, which indicated that the esterification effect of MS was poor, and the compatibility with PBS was poor.…”
Three types of starch with different amylose content were esterified and blended with polybutylene succinate (PBS) to obtain esterified manioc starch/PBS (EMS/PBS), esterified corn starch/PBS (ECS/PBS), and esterified waxy corn starch/PBS (EWS/PBS) composites. The EMS/PBS and ECS/PBS composites with high amylose content displayed typical V-type crystal structures. The original crystals of EWS, which had low amylose content, were disrupted during the esterification process. EWS exhibited the strongest interaction with PBS and the most favorable interface compatibility. The pyrolysis temperature was in order of EMS/PBS < ECS/PBS < EWS/PBS. The elongation at break of the three blends was higher than that of pure PBS. The esterification and plasticization of the EWS/PBS composite were the most comprehensive. The EWS/PBS composite showed the lowest storage modulus (G’) and complex viscosity (η*). The interfacial bonding force of the composite materials increased with more amylopectin, decreasing intermolecular forces and destroying crystal structures, which decreased G’ and η* and increased toughness. The EWS/PBS composite, with the least amylose content, had the best hydrophobicity and degradation performance.
“…In general, the degradation of the composites in the enzyme buffer can include two forms: enzymatic hydrolysis and hydrolysis. Generally, when the two degradation methods work together, the weight loss in the composites increases [ 32 ]. The highest degradation efficiency of the EMS/PBS composite was 75%, which indicated that the esterification effect of MS was poor, and the compatibility with PBS was poor.…”
Three types of starch with different amylose content were esterified and blended with polybutylene succinate (PBS) to obtain esterified manioc starch/PBS (EMS/PBS), esterified corn starch/PBS (ECS/PBS), and esterified waxy corn starch/PBS (EWS/PBS) composites. The EMS/PBS and ECS/PBS composites with high amylose content displayed typical V-type crystal structures. The original crystals of EWS, which had low amylose content, were disrupted during the esterification process. EWS exhibited the strongest interaction with PBS and the most favorable interface compatibility. The pyrolysis temperature was in order of EMS/PBS < ECS/PBS < EWS/PBS. The elongation at break of the three blends was higher than that of pure PBS. The esterification and plasticization of the EWS/PBS composite were the most comprehensive. The EWS/PBS composite showed the lowest storage modulus (G’) and complex viscosity (η*). The interfacial bonding force of the composite materials increased with more amylopectin, decreasing intermolecular forces and destroying crystal structures, which decreased G’ and η* and increased toughness. The EWS/PBS composite, with the least amylose content, had the best hydrophobicity and degradation performance.
The production of polymer particles through suspension polymerization still attracts the attention of academia and industry, resulting in many papers and patents published every year about this theme. Suspension polymerization processes are extensively used because of their many competitive advantages, including the easy separation of the polymer particles, easy removal of the heat of reaction, easy temperature control, and low levels of impurities and additives in the final polymer resin. For this reason, such processes are suitable for production of polymer resins intended for many distinct applications, including biotechnological, medical, and dental applications. In this context, the main objective of the article is to discuss the fundamental aspects of suspension polymerization processes, focusing on the effects of the main process variables on the performance of suspension polymerizations and highlighting new suspension technologies, such as suspension polycondensations, controlled suspension reactions, and continuous operations.
Polybutylene succinate (PBS) and other succinic (co)polyesters are biodegradable polymers with favorable mechanical and thermal properties that find use in many applications. Due to environmental concerns, polymers based on succinic acid (SA) have been gaining attention, as SA can be produced through biotechnological processes. Thus, this review aims to highlight the synthesis and characteristics of PBS and other succinic copolyesters, with emphasis in the works employing metallic catalysts and enzymes. In addition, the modification of the macromolecular structure by copolymerization or postpolymerization is also discussed. Currently, metallic catalysts are normally used in the synthesis of these materials, under conditions of high temperatures, which can favor the occurrence of thermal degradation, increasing the dispersion of chain length distributions. Moreover, the incrustation of metallic catalysts in polymeric materials makes their application in biomedical products difficult, due to toxicity requirements. In this context, enzymatic catalysis is gaining ground, offering milder synthesis temperatures, high selectivity, and uniformity of synthesized products. This biotechnological route can substitute oligomerization processes with metallic catalysis in future industrial processes, producing materials free from metallic contamination. In addition to production by catalytic routes, trends for future applications of succinic (co)polyesters are presented, with emphasis on the value‐added materials sectors.
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