In 1,3:2,4-bis-O-(p-methylbenzylidene)-D-sorbitol(PDTS)/molten i-PP systems,the self-assembling ramified fibrils of PDTS are formed at T_(fg,c)higher than T_c during the cooling process.They function as the nucleators for the nu-cleation of molten i-PP.The ramified fibrils have the following characteristics:i)hexagonal crystal with the lattice cell a=b=30.2,c=4.4 A,and gamma=120 deg,ii)mass fractal structure with large specific surface area,and iii)random orientation.Thus the following properties are induced for the i-PP:i)excellent transparency so that the lamellae build a sheaf-like crystalline superstructure with a small apex angle,ii)iso-directional and improved mechanical properties,and iii)shortened molding time.
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