Strong Memory Effect of Metastable β Form Trans‐1,4‐Polyisoprene above Equilibrium Melting Temperature

• DOI: 10.1002/macp.201700235
• Publication Date: 2017-07-04T15:09:05Z
• Authors: Jie Lu; Haoran Yang; Youxin Ji; Xiangyang Li; Yankun Lv; Fengmei Su; Liangbin Li
• Keywords: Metastability; Tacticity; Spherulite (polymer physics); Crystal (programming language); Atmospheric temperature range

Abstract The memory effect of metastable β form crystals trans ‐1,4‐polyisoprene (TPI) is investigated with its thermodynamically stable α‐TPI as reference. Unexpectedly, β‐TPI exhibits a stronger over α‐TPI. temperature can be 20 °C higher than equilibrium melting point (78 °C), while has lost below the (87 °C). Moreover, ordered structures in memorized melt accelerate spherulite growth, and growth rate depends on time, similar to previous mesomorphic isotactic polypropylene studies, implying phase may have universal effects: wide range, crystal nucleation accelerating. from weak entropic difference isotropic melt, which cannot overcome barrier entanglements phase, leading slow relaxation. This discovery regulate crystalline morphologies polymers by controlling locations different crystals.