| Abstract: | The physical and mechanical properties of interpenetrating polymer networks (IPNs) and semi-I IPNs of the castor oil polyester network and poly(methyl methacrylate) were investigated. In the semi-I IPNs, the second component was a copolymer of poly(methyl methacrylate) and polystyrene (PS) or poly(methyl methacrylate) and poly(n-butyl acrylate) (PnBA). The dynamic mechanical properties indicated the semi-I IPNs to be more compatible than the IPNs. The degree of molecular mixing was higher than that for IPNs. The impact strength showed a gradual increase with the increase in the percentage of PS or PnBA in the copolymer. The effect of the copolymerization of the second component on transparency was investigated. The transparency of the semi-I IPNs increased with the increasing composition of PnBA, but reduced with the increasing composition of PS. These results are discussed in light of existing theories. |
