Chinese Journal of Applied Chemistry ›› 2018, Vol. 35 ›› Issue (9): 1148-1154.DOI: 10.11944/j.issn.1000-0518.2018.09.180217

• Full Papers • Previous Articles    

Effect of Molecular Cross-linking Degrees on the Morphology and Tribological Properties of 1,4-Phenylene Diisocyanate-Based Polyurethane Elastomers

TIAN Yumengab,LI Xueminab,LI Xiaoxiaoad,HUAN Yana,YE Fengc*,YANG Xiaoniuac   

  1. aPolymer Composites Engineering Laboratory,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China
    bUniversity of Science and Technology of China,Hefei 230026,China
    cState Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences,Changchun 130022,China
    dUniversity of Chinese Academy of Sciences,Beijing 100049,China
  • Received:2018-06-20 Accepted:2018-06-26 Published:2018-09-01 Online:2018-08-06
  • Contact: YE Feng
  • Supported by:
    Supported by the Key Deployment Project of Scientific and Technological Innovation of the Chinese Academy of Sciences(No.KGFZD-135-18-011-02), the High-tech Industrialization Special Fund Project for Science and Technology Cooperation of Jilin Province and Chinese Academy of Sciences(No.2017SYHZ0019), the Changchun Science and Technology Project(No.16ss17), the Jilin Province Science and Technology Development Project(No. 20160204031G X)

Abstract:

The friction properties of polyurethane elastomers are of great significance in areas such as marine, automotive, and biomedical applications. However, the fine design of friction properties of such materials through chemical modification strategies still has urgent needs in research and application prospects. In this work, p-phenylene diisocyanate(PPDI) and polytetramethylene ether glycol(PTMG) were used, and the PPDI-based polyurethane elastomers with different degrees of cross-linking were synthesized through varing the molar ratio of two chain extenders of 1,4-butanediol and trimethylolpropane. Results of the Fourier transform attenuated total reflection spectra(FTIR-ATR), wide-angle X-ray diffraction(WAXD) and differential scanning calorimetry(DSC) indicate that the crystallinity of both hard segment and soft segment in polyurethane elastomer is inhibited with the increase of cross-linking degree. Meanwhile, the results of mechanical test show that the elastic modulus of the material decreases, while the friction coefficient of PPDI-based polyurethane elastomer increases. In addition, the hysteresis loop curve shows that the change in the degree of cross-linking also affects the damping properties of the PPDI-based polyurethane elastomer, and the difference in the damping of the polyurethane elastomer is also reflected in the dependence of the friction performance on the rate. This work therefore proposes that by using different degrees of crossl-inking, the crystallinity of hard and soft segments in PPDI-based polyurethane can be changed, which leads to the difference in the elastic and the loss modulus of the material, and the friction properties can thus be controlled, which provides a simple-to-achieve and effective way for the regulation of frictional properties of PPDI-based polyurethane elastomers.

Key words: polyurethane elastomers, degree of cross-linking, tribology, micro-phase separation, elastic modulus