• Clean Technology
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• v.14 no.1
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• pp.29-34
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• 2008

Copolymerizations of propylene oxide (PO) and phthalic anhydride (PA) have been performed in the presence of double metal cyanide (DMC) catalyst as a means of incorporating ester groups in the polyol backbone. DMC catalyst was effective for the copolymerization and the reactivity ratios measured by modified Kelen-$T{\ddot{u}}d{\ddot{o}}s$ equation were $r_1(PA)\;=\;0$, and $r^2(PO)\;=\;0.248$. Four different Polyol samples containing 1.0, 2.1, 7.52, and 11.42 mol% of PA unit were utilized for the synthesis of thermoplastic polyurethanes of their hard segments of 19 wt%. As the incorporated amount of PA increases, the elongation of the resulting polyurethane decreases and the tensile strength and the tensile modulus increase. The modulation of the incorporated amount of PA into polyol backbone was proven to be a feasible way to tune the physical properties of polyurethanes.