Multiblock Thermoplastic Elastomers Derived from Biodiesel, Poly(propylene glycol), and l-Lactide

Abstract

A series of [poly­(l-lactide)–poly­(dimer acid methyl ester-alt-poly­(propylene glycol))–poly­(l-lactide)] n (PLLA–PDP–PLLA) n multiblock copolymers was synthesized in a three-step procedure: PLLA–PDP–PLLA (LDPL) triblock copolymers were synthesized using ring-opening polymerization of l-lactide with PDP macroinitiators, which was prepared via step-growth melt polycondensation based on biodiesel and macro-diol, followed by chain extension of the LDPL triblock with 4,4′-methylenebis­(phenyl isocyanate). Molecular characterization revealed that the synthetic procedures yielded the desired triblock and multiblock copolymers (f PLLA = 0.22–0.27). The relationship between thermal behavior and morphology indicated microphase separation into two domains in both the triblocks and multiblocks. Compared to previously reported triblocks with a high molar mass and PLLA hard blocks with inaccessible order–disorder transition temperature (T ODT) values, the multiblock architectures in this study were found to become disordered at much lower temperatures (T ODT = 82–128 °C). To prepare (LDPL) n multiblocks, coupling low-molar-mass LDPL triblocks without free-standing thin films led to dramatically enhanced tensile properties. The self-adhesive performance of the pressure-sensitive adhesive (PSA) system including the multiblocks was evaluated, showing a peel strength of 3.1 N cm–1, a probe tack of 1.9 N, and static shear strength of >50 000 min, which are values comparable to those of current PSAs. These biodiesel-based thermoplastic elastomers hold promise for sustainability and high value-added economy.

Carbohydrates as Hard Segments for Sustainable Elastomers: Carbohydrates Direct the Self-Assembly and Mechanical Properties of Fully Bio-Based Block Copolymers

“…Overall, we wish to demonstrate that oligo/polysaccharides can be good candidates as the bio-based hard segments of sustainable elastomers. Although bio-based polymers, such as polylactide, − poly­(γ-methyl-α-methylene-γ-butyrolactone), rosin-based polymers, and poly­(itaconimide) have been reported as the hard segments of fully bio-based elastomers, our study could represent the first example of using oligo/polysaccharides in designing such materials.…”

Tannic acid: A sustainable crosslinking agent for high glass transition epoxy materials

“…Researchers have found ways to sustainably source a variety of thermoplastics including polyhydroxyalkanoate, polylactic acid, poly(butylene succinate), poly(trimethylene terephthalate), polyethylene, polypropylene, polyethylene terephthalate, and others . There has even been a significant amount of work in the area of thermoplastic elastomers including triblock copolymers consisting of bio‐derived poly(lactide) sourced from corn and sugar beets reacted with a variety of end groups including poly(menthide) synthesized from (−)‐menthol found in mint leaves, as well as bio‐sourced poly(ethylene glycol), poly(isoprene), and poly(ricinoleic acid) …”

Fabrication of Millable Polyurethane Elastomer/Eucommia Ulmoides Rubber Composites with Superior Sound Absorption Performance

“…It can be seen in Table 3 that the hardness and stress at definite elongation (100% and 300%) of various MPU/EUG composites increased gradually with the increase of EUG content. This was mainly due to the fact that EUG can crystallize at room temperature and thus displayed high modulus, which improved the hardness of various MPU/EUG composites and enhanced their ability to resist external deformation [ 17 , 46 , 47 ]. Additionally, with an increase in the content of MPU, the tensile strength of various MPU/EUG composites decreased first and then increased slightly.…”