Resin transfer molding (RTM) has the potential to manufacture high quality, geometrically complex composite parts. Benzoxazine is a new kind of high performance composite matrix. It can be polymerized with a ring-opening reaction without releasing volatiles. In this article, a novel RTM resin made from aromatic diamine, phenol and formaldehyde is reported. The viscosity and curing behavior of the RTM resin as well as the properties of the cured neat resin and fiber reinforced composite were investigated. The resin has a viscosity lower than 0.5 Pa ⅐ s after 4 hr at 100°C, and can be cured at 180°C. The tensile strength, modulus, and elongation of the cast resin are 94 MPa, 4.6 GPa, and 2.2%, respectively. The flexural strength and modulus of the cast resin are 160 MPa and 4.9 GPa. The flexural strength and modulus of its glass fiber laminate are 662 MPa and 30 GPa. It is very easy to control the viscosity and curing rate of the RTM resin through the addition of reactive dilute agents and catalysts according to the requirement of RTM processing. POLYM. COMPOS., 26:563-571, 2005.

Novel polyimides with side chains containing various methylene spacers and biphenyl end groups were prepared. They were characterized by the inherent viscosity, mechanical properties, and solubility and by Fourier transform infrared, 1 H-nuclear magnetic resonance, Xray diffraction, differential scanning calorimetry, and thermogravimetric analysis. All the polyimides with biphenyl side groups could be formed into tough films. WAXD showed that all the films were apparently amorphous. By incorporating side chains, the solubility was greatly enhanced and all the polyimides with side chains showed good solubility in polar aprotic solvents, while the high moduli and strength of typical polyimides were maintained and even improved. However, the heat-resistant properties such as the thermal stability and glass transition temperature were generally decreased.

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