| 摘要 |
Filled, thermoplastic polyolefin (TPO) compositions having a total energy absorption during impact at −3O° C. of at least 20 ft-lb-f as measured by an Instrumented Dart Impact Test (ASTM D3763) at 6.7 m/s and a peak tangent flexural modulus of >2100 MPa (305,000 psi as measured by ASTM D-790, the composition comprising based on the total weight of the TPO composition; A) 36-56 wt % of a crystalline polypropylene having a MFR of at least 1 and a melting point of at least 160° C. as measured by DSC; and B) 64-44 wt % of an elastomer/filler composition comprising (1) an EAO elastomer having a (1) Tg of less than −50° C. as measured by DSC, (b) tan delta between >2 and 3 as measured at 0.1 rad/s and 190° C. with an Advanced Rheometrie Expansion Systems rheometer. and (c) HDT greater than or equal to the peak melting temperature of the elastomer as measured by DSC, and (2) a platy filler, e.g., talc, the elastomer and filler present at a weight ratio of elastomer to filler of 3:2 to 2:1; the crystalline polypropylene and elastomer present at a weight ratio of polypropylene to elastomer of less than 2.
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