Structures and properties of injection moldings of crystallization nucleator‐added polypropylenes. II. Distribution of higher‐order structures

Flexural test specimens were injection‐molded from polypropylenes added with 0.5 wt % calcium carbonate, talc, p‐tert‐dibutyl‐benzoic acid monohydroxy aluminum, or p‐dimethyl‐benzylidene sorbitol under cylinder temperatures of 200–320°C. Distributions in the flow direction of higher‐order structures such as a*‐axis‐oriented component fraction [A*] and crystalline orientation functions and distributions in the thickness direction of higher‐order structures such as crystallinity, β‐crystal content, the degree of b‐axis orientation to the thickness direction, [A*], and crystalline orientation functions were studied. These higher‐order structures are inhomogeneous in the flow and thickness directions, which strongly influences the product properties such as mechanical and thermal properties.