Morphology of Novel PEAs Containing Two Consecutive Amide Bonds Randomly Distributed Along the Polyester Backbone

Abstract

The morphology of a series of novel segmented PEAs with varying amide content was studied by a combination of DSC, SFM and proton solid state NMR. Semicrystalline polymers organised in a lamellar morphology were obtained for all amide contents. The results of different NMR experiments revealed that a three phase system composed of a rigid phase, an interface and a mobile amorphous phase is the most appropriate model to describe the morphology of these materials. The amount, the chain dynamics and the domain size of each phase were estimated and correlated with the amount of the amide fraction. Such morphological investigations help to understand the macroscopic properties of segmented PEAs for their applications as biomaterials.magnified image

Polyamides – Still Strong After Seventy Years

“…Since the objective of including polyamide is to take advantage of its strongly bonded crystals it would seem that the long amide sequence is preferred. Subsequently, Garg et al [219] reported on the morphology of the copolymer with two-amide sequences. Thermoplastic elastomers are a class of block copolymers in which periodic crystallizable ''hard'' segments are interspersed with ''soft'' segments, each of the latter consisting of a long block of non-crystallizing polymer.…”

Crystallization Behavior of Reactive Blends between PBS and PA6IcoT

“…14−16 The melting and crystallization temperatures were also reported as part of the thermal properties. 17,18 To the best of our knowledge, there is a lack of crystallization studies on PEAs based on crystalline aliphatic polyesters and amorphous aromatic polyamides.…”

“…The polyester and polyamide used in their work were poly­(hexamethylene terephthalate) and poly­(hexamethylene terephthalamide), respectively, both of which have poor biodegradability. Furthermore, DSC data, from which distinct melting and crystallization temperatures were observed for polyesters and polyamides, were used to confirm the blocky microstructure. − The melting and crystallization temperatures were also reported as part of the thermal properties. , To the best of our knowledge, there is a lack of crystallization studies on PEAs based on crystalline aliphatic polyesters and amorphous aromatic polyamides.…”