Liquid PEG₄‐PLLA copolymers: Effect of chirality and molecular weight on mechanical properties

Abstract

The mechanical properties of polylactic acid (PLA), largely determined by its molecular weight and tacticity, can be modified by copolymerization and multi-armed structure, among other things. A series of liquid PEG 4 -PLA copolymers bearing various PDLLA or PLLA of increasing molecular weights was synthesized and characterized.The glass transition temperature and viscosity gradually increased with the molecular weight and the optical purity of the copolymer's PLA segment. The release profiles of two model drugs, bupivacaine HCl and bovine serum albumin were comparable, and controlled by the molecular weight and dissolution of the polymeric carrier. These findings can help in the development of new applications in biomedicine in which viscosity plays a significant role.

Design and Evaluation of Dissolvable Microneedles for Treating Atopic Dermatitis

“…About 70% of the drug was released within 1 h, followed by a more sustained release pattern for up to 4 h. A total of 94% of the drug was released after 5 h (Figure 3B). The relatively fast release of Dex from the MNs can be explained, in part, by the solubility of the hydrophilic 1:2 PVA/PVP composition [43]. The hygroscopic nature of both polymers also contributes to the fast release profile.…”

Effect of viscosity and thermal properties on mechanical properties of PLA materials

“…Viscosity of polymers, as well as the glass transition temperature, is generally growing up with the molecular weight and the optical purity of segment [1,2]. Under a constant vibration pressure amplitude, viscosity deteriorating with the vibration frequency and or at a higher temperature [3][4][5].…”

“…The mechanical properties are revealed by the molecular weight and chirality [1]. The strength was proved to be enlarged with the development of the glass transition temperature [18].…”