Poly(lactic acid) and poly(ε-caprolactone) belong to a family of aliphatic polyesters and have been explored in various applications due to their biodegradable and biocompatible nature. Both PCL and PLA are known to be hydrophobic materials and are immiscible in nature. Blending of PCL and PLA often leads to the macro-phase separation which may significantly alter the properties of the resulting material. In order to reduce the phase separation, several attempts have been made including the formation of block copolymers. Additionally, the architecture of the block copolymer is found to affect the properties of the resulting materials. In line to this, the current work aims at synthesizing block copolymers based on PCL and PLA by changing the molecular architecture. A series of block copolymers are synthesized with different architecture i.e. AB, ABC and BAB type wherein block A, B and C correspond to poly(L-lactic acid), poly(ε-caprolactone) and poly(D-lactic acid) respectively. The molecular weight of the individual blocks is targeted and confirmed by <sup>1</sup>H-NMR spectroscopy. The synthesized copolymers are subjected to thermal, mechanical and crystallization studies in order to determine the effect of polymer architecture on various properties. Differential scanning calorimetry (DSC) thermograms suggest the variations in the glass transition, crystallization and melting behaviour of all the synthesized copolymers. Small angle X-ray scattering provides an information about the lamellar thickness, repeating period of lamellar stacking and lamellar orientation for the synthesized polymers. Additionally, the effect of molecular architecture is evident on the nucleation density and the growth rate of spherulites. Further, the mechanical properties such as tensile strength, elongation, modulus and toughness and found affected by the molecular orientation. Thus, the results indicate that the molecular architecture play an important role in controlling the properties of the block polymer.<br/>

Multicomponent block copolymers consisting of soft and hard segments: Effect of copolymer architecture on the thermal, mechanical, and crystallization properties

2019 Spring National Meeting

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.