Properties of aliphatic polyesters withn-paraffinic side branches

Abstract

Effect of ethyl and n-octyl branches on the properties of poly(ethylene adipate) (PEA) and poly(butylene succinate) (PBS) were investigated. Glass transition and melting temperature, crystallinity, melt viscosity, and spherulite growth rate were decreased with an increase in the degree of the chain branches. Introduction of ethyl branches as well as n-octyl branches into PEA did not improve the tensile strength and modulus, while it reduced elongation and tear strength significantly. The presence of glycerol units less than 0.05 mol/mol of diacid units in PEA as well as in PSB also brought about damaging effects on the properties. Additional amount of glycerol units in the polyesters resulted in the formation of gel. However, addition of n-octyl branches improved elongation and tear strength of PBS considerably without a notable decrease of tensile strength and modulus.

Chain extension and biodegradation of poly(butylene succinate) with maleic acid units

“…PBS usually exhibits its crystallization peak at 5.8°C on the second-scan DSC thermogram. 8 However, low molecular weight PBS crystallizes rapidly so that PBS, whose M w was 4.36 ϫ 10 4 , crystallized to a certain extent during the DSC cooling stage. As a result, the crystallization peak at 5.8°C for PBS is not seen in Figure 2(a).…”

A Green Route for the Preparation of Aliphatic Polyesters via Lipase‐catalyzed Prepolymerization and Low‐temperature Postpolymerization

“…PLA, already commercially available (e.g., NatureWorks), is produced from renewable resources such as corn or sugar beets, it presents mechanical strength, transparency, compostability, and biocompatibility, while its high glass transition point, low crystallization rate, and ductility comprise its main drawbacks 1, 2. On the other hand, biodegradable aliphatic polyesters from diacids and diols, i.e., poly(alkylene dicarboxylate)s, are produced mainly from petroleum‐based monomers, and a limiting factor for their broad use is the low melting temperatures due to the poor intermolecular interactions 3–7. Fossil PBS and its copolyesters with ethylene glycol and adipic acid present a melting point above 100 °C and therefore have been already commercialized (e.g., Bionolle from Showa Highpolymer),5 while the current large development of biobased succinic acid and its derivatives will promote the production of half and of 100% green PBS in the next years.…”

“…Bulk polymerization is usually applied for the preparation of poly(alkylene dicarboxylate)s, following esterification and transesterification routes and using highly effective chemical catalysts, e.g., zinc acetate, dibutyl tin oxide, antimony trioxide,6, 7 titanium tetrabutoxide,3, 4, 6, 7, 12, 13 titanium tetraisopropoxide,12 and tetrabutyl titanate 14. In Table 1, indicative polymerization conditions of recent literature are presented for the chemically‐catalyzed preparation of aliphatic polyesters (PE X .…”

Influence of the nature of the chain breaker on the thermal stability of phthalic anhydride-based polyesters

“…Dicarboxylic acids most used in the synthesis of unsaturated polyesters are adipic acid, azelaic acid, phthalic anhydride, terephthalic acid, isophthalic acid, maleic anhydride, or mixtures thereof, etc., and a glycol, or various combinations of polyhydric alcohols such as monoethylene glycol, propylene glycol, butanediol, trimethylolpropane [6][7][8][9][10]. These variations in structure are designed to improve the quality of the final product and certain mechanical properties and resistance.…”