Interpenetrating polymer networks based on polyol modified castor oil polyurethane and polymethyl methacrylate

The two component reinforced elastomeric interpenetrating polymer networks (IPNs) composed of glycerol modified castor oil polyurethane (CG-PU) and polymethylmethacrylate (PMMA) were synthesized. The effects of polyol modification, change in NCO/OH ratio and polyurethane/PMMA composition on the mechanical, chemical and thermal properties of the IPNs were studied. It was found that among the three IPNs synthesized from (1) unmodified castor oil PU (2) glycerol modified castor oil PU (3) glycerol modified mixture of castor and linseed oil PU and PMMA, glycerol modified PU IPNs (CG-IPN) exhibited better tensile strength and chemical resistance. The detail study of CG-IPNs revealed that tensile strength and hardness increased while elongation decreased with the increase in NCO/OH ratio. However, an exactly reverse trend was observed with the increase in PU composition in PU/PMMA IPNs. The chemical resistance and thermal resistance of the IPNs were unaffected by the change in NCO/OH ratio and PU/PMMA composition. (C) 1998 Elsevier Science Ltd. All rights reserved.