Poly(glycerol sebacate)-Based Polyester–Polyether Copolymers and Their Semi-Interpenetrated Networks with Thermoplastic Poly(ester–ether) Elastomers: Preparation and Properties

Abstract

Poly(glycerol sebacate) (PGS), produced from renewable monomers such as sebacic acid and glycerol, has been explored extensively for various biomedical applications. However, relatively less attention has been paid to explore PGS as sustainable materials in applications such as elastomers and rigid plastics, primarily because of serious deficiencies in physical properties of PGS. Here, we present two new approaches for enhancing the properties of PGS; (i) synthesizing block copolymers of PGS with poly(tetramethylene oxide)glycol (PTMO) and (ii) preparing a blend of PGS-b-PTMO with a poly(ester–ether) thermoplastic elastomer. The consequence of molar ratio (hard and soft segments) and Mn of soft segment on tensile properties of the material was investigated. The PGS-b-PTMO with 25:75 mole ratios of hard and soft segments and having a medium Mn soft segment (5350 g mol–1) exhibits an appreciable increase in percentage of elongation that is from 32% for PGS to 737%. Blends of PGS-b-PTMO and a thermoplastic polyester elastomer, Hytrel 3078, form a semi-interpenetrated polymer network, which exhibits increased tensile strength to 2.11 MPa and percentage of elongation to 2574. An elongation of such magnitude is unprecedented in the literature for predominantly aliphatic polyesters and demonstrates that the simple polyester can be tailored for superior performance.

Control the Mechanical Properties and Degradation of Poly(Glycerol Sebacate) by Substitution of the Hydroxyl Groups with Palmitates

“…The mechanical properties of the PGS alone and other PGS derivatives can also be tuned by changing the curing time and crosslinking densities. [ 27,32,37 ] For example, a shorter crosslinking time typically forms less crosslinks and leads to a lower modulus and a longer elongation as we reported previously. [ 32 ] However, less crosslinks would typically result in a quicker degradation of the elastomer, which is not desired for our applications in small arteries.…”

“…To date, many methodologies have been reported to modulate the physicochemical and biological properties of the PGS and introduce other functions for biomedical applications. [ 25–31 ] Examples include acrylation, tyramine‐functionalization, urethane crosslinking, copolymerization with other monomers and blends with other materials, among others. [ 25,32–36 ] These methods have their own features, but are difficult to simultaneously achieve the above three goals for our applications in small arteries.…”

“…[ 39 ] Like the PGS, the resultant PPGS elastomers would therefore possess good biocompatibility and bioresorbability upon degradation because glycerol and palmitate are endogenous molecules and sebacate can be metabolized for energy. Different with the PGS alone and other PGS derivatives, [ 27,37 ] we expect the palmitate functionalization of the PGS would impart new properties and performance for tissue engineering applications.…”

Citrate Crosslinked Poly(Glycerol Sebacate) with Tunable Elastomeric Properties

“…[ 1–5 ] For example, altering parameters such as molar ratio of monomers and curing temperature, substitution of hydroxyls with other molecules, or copolymerization with other monomers can manipulate the hydrophilicity, elasticity, mechanical properties, and degradation for a given application. [ 1,6–11 ] This has led to its wide applications in tissue engineering, such as cardiac patches, articular cartilage scaffolds, synthetic vascular grafts, and nerve conduits. [ 2,12–17 ] However, thermal crosslinking of the prepolymer requires harsh curing conditions, typically ranging from 120 to 150 °C for 24–144 h. [ 1,6,7,18 ] Such thermal crosslink is time and energy consuming.…”

Enhanced Mechanical Properties of PET‐Based Thermoplastic Elastomers: Brittle–Ductile Transition via Micro Cross‐linking Technology

“…These attractive materials have been widely applied in the fields of coatings, textiles, rubbers, automobile, medical machines, spinning tires, etc . Most of them are block copolymers consisting of soft segments and hard segments synthesized by solution or anionic polymerization such as poly(styrene‐ b ‐butadiene‐ b ‐styrene) (SBS), poly(diol citrate) and poly(glycerol sebacate) (PGS) . Unlike these polymerization strategies, however, melt polymerization offers the following benefits: good quality, high efficiency, little pollution and low cost, and is a better route for the industrial fabrication of TPEs …”