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We developed advanced cellulose-based resin composites consisting of cardanol-bonded cellulose diacetate (CDA), polyester resins and glass fiber, which have high impact strength and bending strength suitable for durable products. By testing the addition of various polyester resins to the PAA-bonded CDA, we found that poly(butylene succinate adipate) (PBSA), which has flexibility and high compatibility with the PAA-bonded CDA, greatly increased its impact strength. Furthermore, adding glass fiber to the PAA-bonded CDA composites with PBSA enhanced its bending strength and impact strength.
Effect of viscosity ratio of the outer/inner solutions on the morphology of core–shell fibers was studied by altering the concentrations of two polymer solutions, poly(methyl methacrylate) and poly(acrylonitrile), as a role model. Nonuniform core–shell structures were observed at low viscosity ratio of PAN/PMMA. By increasing the viscosity ratio of PAN/PMMA, the total diameter and the wall thickness were increased, while the core diameter seems to be gradually decreased. Rheology aspects and suitable ranges of viscosity ratios were discussed and suggested in this work.
The Michael addition of N-heterocyclic carbenes (NHCs) to the unsaturated polyesters, polymaleates and a polyfumarate, produced the polymers bearing the NHCs as side chains in good-to-high yields. The glass transition temperatures of the obtained polymers were widely tunable and increased linearly with the increasing NHC content. The stiff and bulky structures of the NHCs can reduce the mobility of the polymer main chain. The simultaneous Michael addition and transfer hydrogenation of the unsaturated polyesters have also been performed by the reaction with an NHC in the presence of water.
Photo-crosslinkable groups were introduced to β-cyclodextrin (β-CyD) by the reaction of β-cyclodextrins with isophorone diisocyanate and 2-hydroxyethyl acrylate to produce polysubstituted photo-crosslinkable β-CyD (PSβCyD). To yield PSβCyD of a spherical shape, a suspension consisting of PSβCyD and aqueous sodium alginate solution was added dropwise into an aqueous calcium chloride solution. Then, the PSβCyD macromonomer was photo-crosslinked with ultraviolet radiation to obtain β-CyD polymer beads.
The 1,1,3,3,5,5,7,7-octamethyltetrasiloxane-containing gelator, (R, R)-g/Si, was synthesized by a hydrosilylation with a gelation-driving segment based on trans-(1R, 2R)- 1,2-diaminocyclohexane. Gelation abilities were investigated in the mixed solvents of HDEH, liquid paraffin, and D5. (R, R)-g/Si could form stable and transparent gels due to the flexible octamethyltetrasiloxane segment.
Poly(L-lactide-co-glycolide)-b-poly(ɛ-caprolactone) multiblock copolymers (PLGA-PCL MBCs) were synthesized by the self-polycondensation of PLGA-PCL diblock copolymers (PLGA-PCL DBCs) in the presence of condensation agents. The phase-segregated PLGA domains acted as hard domains, improving the tensile properties. The hydrolytic degradation of PLGA-PCL MBC films in phosphate-buffered saline (PBS: pH=7.4) proceeded much faster than that of poly(L-lactide) (PLLA)-PCL MBC.
New organically bridged trialkoxysilanes containing 1,2,3-triazole moieties were synthesized. They were polymerized by sol–gel reactions, giving bridged silica membranes. Water separation properties of the membrane were investigated using a 2000 p.p.m. NaCl aqueous solution, as being 3.7–5.4 × 10−13 m3/m2·Pa· s of water permeance and 95–96% of NaCl rejection. Separation of neutral solutes such as 2-propanol, glucose and maltose from water by the membrane was also examined. The cutoff molecular weight (solute molecular weight on 90% rejection) was estimated to be 165.
The small-angle X-ray scattering intensity from the coexisting concentrated phase was measured in a phase-separated aqueous solution of the thermosensitive block copolymer poly(2-isopropyl-2-oxazoline)-b-poly(2-ethyl-2-oxazoline) under amphiphilic conditions (50 °C). The concentrated phase was disordered with no sign of micro phase separation. In addition, the scattering from individual copolymer chains and their aggregates existing in the concentrated phase hardly contributed to the total scattering intensity of the phase-separated colloidal solution of the block copolymer.
We synthesized difunctional and trifunctional vinyloxiranes and investigated the synthesis of networked polymers via the radical ring-opening homopolymerization or copolymerization of these monomers. The obtained networked polymers contained vinyl ether structures in the main chain, as confirmed by infrared analysis. In addition, we investigated the radical ring-opening copolymerization of monofunctional vinyloxirane or adamantane-substituted vinylcyclopropane. Networked polymers with various crosslinking densities were obtained, and the heat resistance and volume change of these polymers were evaluated before and after curing.
Stereocomplexes of polylactide with both terminals conjugated to bio-based aromatic compounds, with benzyl alcohol (b1) as an initiator and 3,4-diacetoxycinnamic acid (DACA) as a protection group, were easily formed via inkjet printing techniques based on even layer-by-layer assembly (DACA-SCb1-LbL) and solution mixing (DACA-SCb1-mix). The thermal properties of the stereocomplexes were superior to those of the original PLAs. Inkjet printing is a powerful method of forming functional, thermally stable PLA stereocomplexes with both terminals conjugated.
Schematic representation depicts the synthesis, microstructure and EMI shielding properties of functional cotton and nylon fabrics based on polyaniline nanofibers.
