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Interpenetrating polymer networks (IPNs) based on blocked polyurethane (BPU)/phenolic (PF) were prepared using simultaneous polymerization method. The IPN was prepared from BPU prepolymer with m-xylylenediamine as the chain extender and PF prepolymer using p-toluene sulfonic acid as a catalyst. From Fourier transform infrared spectra analysis, it was found that the major reactions in the BPU/PF IPN system are the polymerization of BPU/MXDA and the self-polymerization of PF. It was confirmed from scanning electron micrography that the BPU/PF IPN compatibility of the networks was improved, and the system was heterogeneous and more than one phase existed in the IPN. The tensile properties, flexural properties, impact, and hardness of the prepared IPN were studied. To obtain the best mechanical properties of IPN materials, the filler added in IPN materials has to be investigated. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers

The mechanical properties of blocked polyurethane(PU)/epoxy interpenetrating polymer networks (IPNs) were studied by means of their static and damping properties. The studies of static mechanical properties of IPNs are based on tensile properties, flexural properties, hardness, and impact method. Results show that the tensile strength, flexural strength, tensile modulus, flexural modulus, and hardness of IPNs decreased with increase in blocked PU content. The impact strength of IPNs increased with increase in blocked PU content. It shows that the tensile strength, flexural strength, tensile modulus, and flexural modulus of IPNs increased with filler (CaCO3) content to a maximum value at 5, 10, 20, and 25 phr, respectively, and then decreased. The higher the filler content, the greater the hardness of IPNs and the lower the notched Izod impact strength of IPNs. The glass transition temperatures (Tg) of IPNs were shifted inwardly compared with those of blocked PU and epoxy, which indicated that the blocked PU/epoxy IPNs showed excellent compatibility. Meanwhile, the Tg was shifted to a higher temperature with increasing filler (CaCO3) content. The dynamic storage modulus (E′) of IPNs increased with increase in epoxy and filler content. The higher the blocked PU content, the greater the swelling ratio of IPNs and the lower the density of IPNs. The higher the filler (CaCO3) content, the greater the density of IPNs, and the lower the swelling ratio of IPNs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1826–1832, 2006

This work presents a process developed to manufacture glass fiber-reinforced vinyl ester (VE)/nano-Al2O3 matrix composites by pultrusion method. The matrix prepolymer for pultrusion in this study was prepared from blends of VE, initiator (t-butyl perbenzoate), and nano-Al2O3. The process feasibility and kinetic analysis of the unidirectional glass fiber-reinforced VE/nano-Al2O3 matrix composites by pultrusion have been investigated. From the investigations of the long pot life of VE/nano-Al2O3 matrix, the high reactivity of VE/nano-Al2O3 matrix, and excellent fiber wet-out of VE/nano-Al2O3 matrix and glass fiber, it was found that the VE/nano-Al2O3 matrix showed excellent process feasibility for pultrusion. A kinetic autocatalytic model, dα/dt = A exp(−E/RT)αm(1 − α)n, was proposed to describe the curing behavior of glass fiber-reinforced VE/nano-Al2O3 matrix composites. Kinetic parameters for the model were obtained from dynamic differential scanning calorimetry scans using a multiple regression technique. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012