Processing‐structure‐mechanical property relationships of semicrystalline polyolefin‐based block copolymers

Abstract

ABSTRACT:The incremental plastic deformation of the crystals of block copolymers made of semicrystalline polypropylene endblocks and amorphous ethylene-r-propylene midblocks occurring during step cycle tensile tests has dramatic effects on the stress-strain curves. This can be understood from the evolution of the morphology and of the microstructure of the crystalline blocks revealed by X-ray scattering experiments.

A model for failure in thermoplastic elastomers based on Eyring kinetics and network connectivity

“…Under stress the morphology changes differently for soft grades (mainly composed of SBs) and hard grades (mainly composed of HBs). Direct experimental observations [9,15,[17][18][19][20][28][29][30][31] show that soft TPE materials break their network of HB crystals and develop a characteristic fibrillar structure when stretched beyond 100%-200% strain. In such a structure, to a lesser extent found in harder TPEs, crystalline domains formed by HBs tend to align in planes perpendicular to the strain direction, whereas SBs, bridging different crystalline domains, are progressively stretched.…”

Critical formation conditions for β-form hybrid shish-kebab and its structural analysis

“…[1][2][3][4][5][6] Since polymer crystallization is a kinetically controlled process, variations in stress and temperature and the presence of additives all have a signicant inuence on the nal crystalline structure. [1][2][3][4][5][6] Since polymer crystallization is a kinetically controlled process, variations in stress and temperature and the presence of additives all have a signicant inuence on the nal crystalline structure.…”

Structure and Properties of Low-Isotacticity Polypropylene Elastomeric Fibers Prepared by Sheath-Core Bicomponent Spinning

“…Development of metallocene catalyst provided the technologies for designing new types of polymers such as those with narrow molecular weight and composition distributions, controlled stereo regularity [1][2] , copolymerization [3][4][5][6][7] etc. Especially, development of polymers with elastomeric characteristics is widely investigated recently [8][9][10][11][12][13]. Elastomeric fibers and elastomeric non-woven fabrics produced from such polyolefin elastomers can be applied widely for the production of diapers, sanitary goods, hygiene products, and materials for medical uses.…”