Thermal Behavior, Structure and Morphology of Propene/Higher 1-Olefin Copolymers

Dependence of phase transitions on composition in isotactic poly(propylene-co-1-pentene-co-1-hexene) terpolymers

“…Comonomers like 1-pentene or 1-hexene are not usual in the synthesis of commercial copolymers but could generate attractive materials if the appropriate balance of characteristics is achieved. Moreover, an additional crystalline lattice has been reported to be developed [9][10][11][12][13][14][15][16][17][18][19][20] in these copolymers with relatively high amounts in 1-hexene and/or 1-pentene. This polymorph was labeled as trigonal d form and it was exclusively obtained at contents above around 14 mol%, while variable proportions of d crystals with the monoclinic a modication were found in the comonomer range from around 10 to 13 mol%.…”

“…There is not in literature a complete evaluation of phase transitions for either those propylene based copolymers with 1pentene or 1-hexene or their terpolymers, although several analyses at room temperature of crystal morphology, stretched bers and mechanical properties as well as melting and crystallization behavior at a specic scanning rate have been performed. 9,11,17,19,20 Accordingly, due to their fundamental academic interest and their empirical importance, this work is now focused on learning about the dependence of phase transitions that take place in these terpolymers as function of global comonomers content, comonomers ratios, and crystallization and recrystallization conditions as well. The eventual competition between polymorphs will be established and compared with that existing in the corresponding poly(propylene-co-1pentene) and poly(propylene-co-1-hexene) copolymers.…”

Mesophase features in isotactic poly(propylene‐co‐1‐heptene) copolymers

“…This attention to i‐ PP copolymers led also to the discovery of a new trigonal polymorph, obtained in copolymers at high contents (more than around 10 mol%) of 1‐pentene or 1‐hexene or in terpolymers of both co‐units . Very few investigations, however, have been dedicated to propylene‐ co ‐1‐heptene (cPHp) copolymers and those published are mostly focused on several characteristics of copolymerization kinetics and of the resulting microstructure . We have recently published a paper concerning the details of the synthesis and molecular characterization of several cPHp copolymers in a broad range of compositions, together with preliminary results on several aspects of some structural and mechanical features.…”

Comparative investigation on crystallization conditions dependence of polymorphs composition for β‐nucleated propylene/ethylene copolymer and propylene homopolymer

“…Random copolymer of propylene with low content ethylene is one of the successful examples. A small amount of randomly inserted ethylene could be regarded as chemical defects along the iPP chains, which induces a better transparency and higher impact strength compared with PPH 3–7. As a semicrystalline polymeric material, these improved final properties of PPR are strongly depended upon its crystallization characteristics, which is closely related to the process conditions and intrinsic macromolecular structures 4, 5…”

“…A small amount of randomly inserted ethylene could be regarded as chemical defects along the iPP chains, which induces a better transparency and higher impact strength compared with PPH. [3][4][5][6][7] As a semicrystalline polymeric material, these improved final properties of PPR are strongly depended upon its crystallization characteristics, which is closely related to the process conditions and intrinsic macromolecular structures. 4,5 As widely acknowledged, iPP is a typical polymorphic material with several crystalline forms, such as a, b, and c form, as well as a intermediate order mesomorphic phase.…”