| 摘要 |
PURPOSE:To provide a composition having excellent heat resistance, injection moldability, cold resistance and mechanical performance by compounding a specific thermoplastic polyurethane with a small amount of a thermoplastic graft polymer. CONSTITUTION:The thermoplastic polyurethane composition comprises 92-99wt.% of a thermoplastic polyurethane and 8-1wt.% of a thermoplastic graft polymer, the polyurethane being prepared from (A) a polyesterdiol and/or a polycarbonatediol containing groups of formula I and II and/or III as essential structural units and having an average mol.wt. of 1500-3500, (B) a diisocyanate and (C) a chain-elongating agent so that the sum of the weights of the components B and C is 23-56% based on the sum of the weights o the components A, B and C, the graft polymer being prepared by graft-polymerizing an aromatic vinyl compound and a cyanized vinyl compound to an elastomer. The sum of the mol fractions of the groups of formulas II and III is >=10% based on the sum of the mol fractions of the groups of formulas I, II and III, and the sum of the mol fractions of the groups of formulas I and II is >=50% based on the sum of the mol fractions of the structural units originated from the diols. |
