Acta Phys. -Chim. Sin. ›› 2012, Vol. 28 ›› Issue (02): 494-498.doi: 10.3866/PKU.WHXB201111233

• PHYSICAL CHEMISTRY OF MATERIALS • Previous Articles    

An Optical Microscopy Study on the Solvent-Induced Crystalline Morphology of Ladder Polyphenylsilsesquioxane

LI Pei-Fang1, YAN Shou-Ke2, REN Zhong-Jie2   

  1. 1. College of Physics and Electronic Information, Inner Mongolia University for the Nationalities, Tongliao 028043, Inner Mongolia, P. R. China;
    2. State Key Laboratory of Chemical Resource Engineering, School of Material Science and Engineering, Beijing University of Chemical Technology, Beijing 100029, P. R. China
  • Received:2011-10-11 Revised:2011-11-09 Published:2012-01-11
  • Contact: REN Zhong-Jie E-mail:renzj@mail.buct.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (21104002,11164020).

Abstract: Spherulites of rigid chain ladder polyphenylsilsesquioxane (PPSQ) were produced through solvent-induced crystallization. The influences of solution concentration, solvent evaporation time, and temperature on the spherulitic morphology of PPSQ were studied by optical microscopy. Diluting the solution was found to have the same effect as elevating the crystallization temperature. The size of the spherulites increases with either decreasing concentration or increasing temperature. This is caused by the enhanced solubility of PPSQ in xylene under such conditions. Extending the solvent evaporation time while leaving the other conditions unchanged also leads to the formation of larger spherulites. The invariance of spherulitic structure upon sample rotation suggests that the spherulites possess a uniform crystallographic orientation. The negative optical characteristics of spherulites indicates that the PPSQ molecular chains are oriented in the tangential direction of the spherulite. Considering the high rigidity of the molecules, an organization model of PPSQ spherulite is proposed.

Key words: Polyphenylsilsesquioxane, Crystallization, Solvent induction, Spherulite, Rigid chain

MSC2000: 

  • O641