Structure of solution-grown trans-1,4-polyisoprene crystals: 4. Effect of concentration on crystal form and melting temperature

✍ Scribed by Yoriko Inomata; Seiichi Kawahara; Yasuyuki Tanaka; Ploenpit Boochathum

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 403 KB
• Volume: 37
• Category: Article
• ISSN: 0032-3861
• DOI: 10.1016/s0032-3861(96)00416-8

✦ Synopsis

The crystallization of synthetic trans-1,4-polyisoprene (TPI) was carried out in 0.05 to 20.0% (wt/vol) hexane, octane and amyl acetate solutions and the melting temperature, T,, of the resulting crystals was measured by differential scanning calorimetry (d.s.c.). The crystal form and T, of the crystals were independent of the concentration of the solutions. On crystallization at low temperatures, TPI crystals appeared before the TPI solutions reached the desired crystallization temperature, T,, and the T,,, was independent of the T,. This phenomenon was quantitatively analysed with respect to the conversion temperature and the crystallization conditions. In contrast, at high temperatures, TPI crystals were observed after the TPI solutions reached a given T,, and the T, was dependent on the T,.