Sustainable Thermoplastic Elastomers Derived from Lignin Bio‐Oils via an ABA Triblock Copolymer Strategy

Abstract

A lignin‐derived polyacrylate, namely, poly(guaiacyl acrylate) (PGA), is evaluated as an end block in linear ABA triblock copolymer‐based sustainable thermoplastic elastomers. Triblock copolymers containing a rubbery poly(methyl acrylate) (PMA) midblock and glassy PGA end blocks are prepared via Cu(0)‐mediated living radical polymerization or single electron transfer living radical polymerization. A suite of triblock copolymers with different block ratios and a constant end block molecular weight is prepared. Even a low‐end block content (<5% mole ratio) can significantly increase the material's mechanical strength (3–7 folds) and long elongation at break. The enhanced mechanical properties are attributed to microphase separation morphologies evidenced by calorimetric and scattering analyses. These elastomers also exhibit enhanced thermal stability compared with that of their parent homopolymers.

Recent advances on the structure–properties relationship of multiblock copolymers

“…64,65 On top of this, MBCs progressively become eco-friendly, incorporating biodegradable HSs, 66,67 without significant loss of mechanical properties. 68 This great variety comes from continuous progress in chemistry, making it possible to modify on-demand the number of segments, their length and the polymers architecture, 69 resulting in a wide range of accessible microstructures. Beyond their applications as bulk materials, it is worth noting that their association with an appropriate solvent can result in astonishing self-assembled structures serving as drug delivers, 70 chameleon-like skin, 15 or spatio-temporal reversible networks.…”

“…Besides, TPEs are frequently used as bitumen modifiers, 53,54 adhesives, 55,56 energy dissipators, 57 reinforcing fibers, 58 ground coverings, polyelectrolytes, 42,59 compatibilizers, 60 strain sensors, 61,62 antibacterial coatings 63 and particularly in the car industry as dashboard elements or other automotive parts 64,65 . On top of this, MBCs progressively become eco‐friendly, incorporating biodegradable HSs, 66,67 without significant loss of mechanical properties 68 . This great variety comes from continuous progress in chemistry, making it possible to modify on‐demand the number of segments, their length and the polymers architecture, 69 resulting in a wide range of accessible microstructures.…”

Closed-loop recycling of lignin-based sustainable polymers with an all-hydrocarbon backbone

“…[4][5][6][7][8][9][10] These labile chemical bonds could also lead to undesirable mechanical performance reduction and depressed thermal stability compared with polyolefins. 11 In the age of controlled polymerization, nature-derived molecular biomass has been customized into versatile renewable monomers and building blocks through macromolecular engineering, [12][13][14][15][16][17][18][19] including living polymerization and postmodification strategies (e.g., anionic polymerization, 20 atom transfer radical polymerization (ATRP), 21,22 single electron transfer living radical polymerization (SET-LRP), [23][24][25] reversible addition-fragmentation chain transfer (RAFT) polymerization, [26][27][28][29] ring-opening polymerization, [30][31][32] and click chemistry 33,34 ) as synthesis tools. The inert carboncarbon bonds on their backbone make sustainable polymers strong and tough to compete with the performance of commodity polymers, such as polyolefins manufactured from petroleum chemicals.…”

Sustainable Multiblock Copolymer Elastomers Derived from Lignin with Tunable Performance toward Strong Adhesives and UV-Shielding Materials

“…To overcome this challenge, sustainable polymers derived from renewable resources have attracted great attention because of their huge potential to replace nonrenewable fossil-based incumbent polymers. − As the second most abundant natural biomass after cellulose, lignin has been frequently used as functional bioresource fillers to fabricate green composite materials with enhanced properties. − Alternatively, lignin can be utilized as the raw material to produce biobased aromatic-containing platform compounds, such as vanillin, syringol, guaiacol, eugenol, and syringic acids, offering new avenues for the preparation of lignin-based sustainable polymer materials . Due to the existence of a bulky aromatic ring side group, lignin-based methacrylate or acrylate monomers are ideal rigid segments to prepare the glassy blocks in elastomers . Recently, Zhang and co-workers synthesized well-defined lignin-based triblock copolymers as high-temperature TPEs via one-step block copolymerization, these elastomers were highly transparent and could be further applied in optical and temperature-resistant devices .…”