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This focused review is an overview of recent research on bio-based polymers produced by the controlled/living polymerization of naturally occurring or derived renewable monomers, such as terpenes, phenylpropanoids and itaconic derivatives. The judicious choice of initiating system, such as controlled/living cationic or radical polymerization, which was borrowed from conventional petrochemical monomers, not only allowed the polymerization to proceed efficiently but also produced well-defined bio-based polymers with high performance from these renewable monomers.
Poly(amino acids) and polypeptides have the potential to contribute significantly to a biomass-based and sustainable society, due to their biomass origin, functionality, and unique physical properties. The recent progress of chemo-enzymatic syntheses of polypeptides as well as studies on peptides and silks as functional and structural materials is reviewed.
Schematic illustration of the structural change of catalyst ink under drying process. For catalyst ink dried to a concentration ratio of four, both the carbon agglomerates size and the Nafion shell thickness become smaller.
We examined the crystallization behavior of poly(ɛ-caprolactone) (PCL) chains in binary blends of PCL-block-polyethylene copolymers and PCL homopolymers using synchrotron SAXS/WAXD. When PCL homopolymers were localized between PCL blocks in lamellar microdomains (dry brush), the crystallinity of PCL chains showed a composition-dependent increase, suggesting the formation of separate PCL lamellar crystals. When PCL homopolymers were uniformly mixed with PCL blocks (wet brush), the time evolution of crystallinity was identical to that of PCL blocks, indicating the formation of a mixed crystal of PCL blocks and PCL homopolymers.
Drag force on micron-sized particles in an aqueous medium was determined and compared with that predicted by the Stokes’ law. Effect of a number of parameters such as surface morphology of particles, particle size, and so on on the drag force acting on the microparticles in an aqueous medium was systematically investigated. Surface morphology was found to strongly affect the drag force working on the microparticles. In addition surface charge, roughness, and physical nature of microparticles were also found involved in the alteration of the drag force.
An amphiphilic liquid-crystalline block copolymer consisting of hydrophilic poly(4-vinylpyridine) (P4VP) and hydrophobic polymethacrylate with liquid-crystalline stilbene mesogens in the side chain (PMA(Stb)) was synthesized using reversible addition–fragmentation chain-transfer (RAFT) polymerization. The GISAXS and TEM measurements show that perpendicularly aligned P4VP cylinders are spontaneously formed in the PMA(Stb) matrix with a smectic layer of the liquid crystal through microphase separation.
Poly(methyl methacrylate) (PMMA) in a miscible blend with polycarbonate (PC) is segregated on the high temperature side in the temperature gradient beyond the glass transition temperature of PC.
An effective method for the synthesis of the rotaxane cross-linked polymers (RCPs) was developed using a metal-containing supramolecular cross-linker (MSC). Radical polymerization of several vinyl monomers and bulky end-capped comonomer afforded RCPs in high yields. The obtained RCPs exhibited thermal properties corresponding to their respective polymer skeletons. Swelling ratio gradually increased with the decreasing amount of the steric comonomer units, indicating that the sliding ability of the movable cross-linker is strongly related to the swelling ability.
