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The origin of the reaction rate acceleration in the microwave-assisted synthesis of poly(butylene succinate) (PBS) was investigated by measuring the rate of removal of the water by-product from the reaction solution under equivalent reaction conditions using both microwave and conventional heating methods. Microwave heating selectively activated and removed the water from the reaction solution more rapidly and to a greater extent than oil bath heating. These results indicate that the principal effect of microwave irradiation in the synthesis of PBS was the accelerated removal of the water by-product.
MMA-BnMA copolymers with various monomer sequences (blocky, random, alternating tendency) were prepared by partial modifications of atactic poly(BnMA) or by direct copolymerization of MMA and BnMA. 13C NMR spectra of the copolymers were subjected to principal component analysis, one of the standard procedures of multivariate analysis. The analysis showed clearly the formation of highly blocky copolymers by hydrogenolysis as well as the formation of copolymers with somewhat alternating tendency by the acidic debenzylation, saponification, and transesterification at late processes of the reactions.
The effects of long-term storage of poly(3-hydroxbutyrate-co-3-hydroxyvalerate) were evaluated over a range of temperatures. As the storage temperatures were increased towards 100 °C, secondary crystallisation resulted increasing the melting point, Tg, modulus and strength. At 125 and 150 °C secondary crystallisation and degradation occurred simultaneously; the effects of degradation masked by secondary crystallisation. The significant observation is that the degradation process remains active at storage temperatures well below the melting point and long-term stability of P(3HB-co-3HV) is not only affected by secondary crystallisation, but also sub-melting point degradation.
The interphase structure of isotactic poly(methyl methacrylate) (it-PMMA)/aluminananoparticle mixtures obtained from tetrahydrofuran (THF) solution was discussed. The it-PMMA in the mixtures forms two amorphous phases (crystallizable and incrystallizable phases) depending on casting conditions from THF. The polymer interphase on Al2O3 particles changes into a crystallizable structure with a trans-gauche rich conformation and amorphous. The interphase shows a lower Tg than the melt-cast one and is easy to crystallize at low temperature. The novel structure was formed by the conformation freezing of the polymer at Al2O3 surface.
Random copolymers (P(M100-m/T
m
)) composed of 2-methacryloyloxyethyl phosphorylcholine, which suppresses protein fouling, and 3-(triethoxysilyl)propyl methacrylate, which can react covalently to the glass surface, were prepared via photoinitiated radical polymerization. Coating of the glass with P(M100-m/T
m
) was confirmed by red fluorescence from Rhodamine 6G. The protein antifouling properties of the P(M100-m/T
m
) coating on glass were confirmed using fluorescence-labeled proteins.
The introduction of structural defects into ordered mesoporous carbons is demonstrated based on block copolymer-templating and high-temperature carbonization of N-containing polymers. N-atom removal during high-temperature heat treatment induces structural defect formation, and the use of soft-templating yields dense mesostructures tough enough to maintain ordering upon defect introduction.Please change the graphical abstract to the revised one sent by email separately.
Water-in-oil (W/O) gel-emulsions consisting of water and a monomer were successfully prepared using N-3-hydroxypropylcarbonyl-L-isoleucyl-aminooctadecane as a gelator. Low-temperature polymerization of the gel-emulsions with a redox initiator was performed to obtain the corresponding porous polymers. Polymerization of gel-emulsions containing bifunctional monomers gave crosslinked porous polymers, which were found to be mechanically robust and solvent resistant. The adsorption capacities of the polymers toward several liquids were assessed and rationalized in terms of the surface microstructures of the polymers. The time courses of the adsorptions were investigated, revealing a two-step adsorption process comprising rapid permeation into the cavities of the porous polymers followed by a slow swelling step.
