Enhancing the drawability of a polyester by copolymerization with a second type of crystallizable block

Abstract

A polyester-amide segmented block copolymer with short monodisperse amide segments was synthesized along with its neat polyester counterpart. The copolymer, containing 10 wt % amide, displayed a T g and T m for the polyester phase as well as a high T m corresponding to the polyamide. The high-melting amide segments enhanced the dimensional stability of the copolymer and also considerably increased the crystallization rate of the polyester segments. As compared to the neat polyester, the polyester-amide block copolymer could be drawn at higher temperatures and to higher draw ratios. The maximum draw ratio for this copolymer was obtained just a few degrees below the melting temperature of the polyester segments, and as a result of these higher draw ratios, the fracture stresses were higher. In conclusion, a short monodisperse amide segment in a polyester-amide block copolymer increased the crystallization rate of the polyester, enhanced the dimensional stability, allowed a higher maximum draw ratio, and raised the fracture strength.

Amide-containing segmented copolymers

“…Anionic ring-opening polymerization of CLA and PCLO initiated with solid CLA-MgBr yielded ductile films with reduced tensile properties compared to PEA copolymers produced from CLA and CLO alone [100]. Others have reported PEA segmented copolymers possessing a poly(ester) T g , as well as T m 's of the crystalline polyester and amide-containing HS, suggesting a complex three phase morphology [95]. However, some PEA copolymers that contain non-uniform HS lengths displayed two melting transitions attributed to crystals containing a single ester amide group and those containing 2 or more ester amide groups [90].…”

Ideal Molecular Weight Distributions of Multiblock Copolymers Prepared via RAFT Polymerization

“…[11][12][13] Multiblock copolymers with crystallizable segments are the basis of novel semicrystalline materials with promising applications. 14 For many applications, and especially for studying their defined properties, it is generally desired that the multiblock copolymers possess a narrow, well-defined distribution of blocks.…”

“…Multiblock copolymers have gained attention for their ability to form ordered structures when they consist of chemically distinct segments with sufficient length. − Their most important applications include the use as bulk materials that belong to the class of thermoplastic elastomers, which material properties rest on the effect of microphase separation, , as compatibilizers , for blends of immiscible homopolymers, and as pressure-sensitive adhesives. , There are examples of multiblock copolymers that are known to form responsive polymeric hydrogels, smart materials that have potential applications in drug delivery, tissue engineering, and as chemical and biological sensors. − Multiblock copolymers with crystallizable segments are the basis of novel semicrystalline materials with promising applications . For many applications, and especially for studying their defined properties, it is generally desired that the multiblock copolymers possess a narrow, well-defined distribution of blocks.…”

Semi-Aromatic Polyether Amide Thermoplastic Elastomer: Nucleophilic Substitution Polymerization and Properties

“…Besides, in order to enhance some aspects of performance like mechanical property, thermal property, and so on, the elastomers with more kinds of blocks were investigated gradually and systematically. Gaymans 27 prepared a polyester-amide-segmented block copolymer with short monodisperse amide segments and its neat polyester counterpart. The high-melting amide segments enhanced the dimensional stability of the copolymer and also considerably increased the crystallization rate of the polyester segments.…”