Research articles

Well-defined aniline-chain-end-functionalized regioregular poly(3–hexylthiophene)s (P3HT-NH₂) have been synthesized on the basis of Grignard metathesis polymerization. The selectivity of monofunctionalization and the high degree of amine functionality (85–92%) were confirmed by MALDI-TOF mass spectroscopy. A block copolymer through ionic interaction was successfully synthesized simply by blending P3HT-NH₂ with carboxy chain-end-functionalized polystyrene. Thermal and optical properties of the block copolymer are investigated by DSC, TGA and UV-vis spectroscopy. The self-assembly behavior of the polymer was observed by AFM showing nanofibril structures with 12–15 nm width.

Three C₂₁-based reactive polyamides with various amine values as epoxy-curing agents were synthesized from tung oil and different polyamines. It was found that the cured materials were superior to those cured by widely used C₃₆-based polyamides with regard to mechanical properties. The glass transition temperatures of three cured C₂₁-based polyamides were found to be higher than that of C₃₆-based polyamides. The curing kinetics were studied and nonisothermal DSC curves show a good agreement with theoretically calculated ones.

Transparent and homogeneous hybrids were synthesized from poly(methyl methacrylate) (PMMA) and aqueous dispersed zirconium oxide nanocrystals (ZrO₂-NCs) with a coupling agent, 3-(methacryloxy)propyltrimethoxysilane (MPTS). The covalent bonding between PMMA- and MPTS-modified ZrO₂ nanocrystals is crucial to obtain nanoscale dispersed hybrid materials. The hybrid films retained good optical transparency compared with that of PMMA/ZrO₂ blend composites and will be promisingly applied for optical functional materials and coatings.

Direct condensation polymerization of N-alkylated aminobenzoic acid was carried out using hexachloroethane, triphenylphosphine and pyridine as condensation reagents. Pale-yellow, fibrous polymers (PABA_n, where n is the number of carbon atoms of the side chain) were obtained in 46–87% yields with an inherent viscosity of 0.30–1.18 per 100ml g⁻¹ (sulfuric acid, 30 °C). DSC analysis and powder X-ray scattering of polymer samples indicated that PABA_n with Me, Pr, Bu, Pe and Ste as side chains were crystalline polymers. X-ray scattering profiles indicated that PABA_n with n=0, 3, 4 and 5 crystallized in an orthorhombic lattice, whereas PABA₁ crystallized in a monoclinic lattice. PABA₁₇ crystallized with hexagonal packing at the long side chain with an interplanar spacing of 4.2Å.