Get access

Effect of silk fiber to the mechanical and thermal properties of its biodegradable composites

Authors

  • Mei-Po Ho,

    1. Centre of Excellence in Engineered Fiber Composites, Faculty of Engineering and Surveying, University of Southern Queensland, Toowoomba, Queensland, Australia
    Search for more papers by this author
  • Hao Wang,

    1. Centre of Excellence in Engineered Fiber Composites, Faculty of Engineering and Surveying, University of Southern Queensland, Toowoomba, Queensland, Australia
    Search for more papers by this author
  • Kin-Tak Lau,

    Corresponding author
    1. Centre of Excellence in Engineered Fiber Composites, Faculty of Engineering and Surveying, University of Southern Queensland, Toowoomba, Queensland, Australia
    2. Department of Mechanical Engineering, The Hong Kong Polytechnic University, Kowloon, Hong Kong, SAR, China
    • Centre of Excellence in Engineered Fiber Composites, Faculty of Engineering and Surveying, University of Southern Queensland, Toowoomba, Queensland, Australia
    Search for more papers by this author
  • Jinsong Leng

    1. Center for Smart Materials and Structures, School of Aeronautics, Harbin Institute of Technology, China
    Search for more papers by this author

Abstract

In recent years, natural fiber-reinforced biodegradable thermoplastics are being recognized as an emerging new environmentally friendly material for industrial, commercial, and biomedical applications. Among different types of natural fibers, silk fiber is a common type of animal-based fiber, has been used for biomedical engineering and surgical operation applications for many years because of its biocompatible and bioresorbable properties. On the basis of our previous study, a novel biodegradable biocomposite for biomedical applications was developed by mixing chopped silk fiber and polylactic acid (PLA) through the injection molding process. This article is aimed at studying the dynamic mechanical and thermal properties of the composite in relation to its biodegradation effect. At the beginning, it was found that the initial storage modulus of a silk fiber/PLA composite increased while its glass transition temperature decreased as compared with a pristine PLA sample. Besides, the coefficient of linear thermal expansions (CLTE) of the composite was reduced by 28%. This phenomenon was attributed to the fiber–matrix interaction that restricted the mobility of polymer chains adhered to the fiber surface, and consequently reduced the Tg and CLTE. It was found that the degraded composite exhibited lower initial storage modulus, loss modulus and tan delta (tan δ) but the Tg was higher than the silk fiber/PLA composite. This result was mainly due to the increase of crystallinity of the composite during its degradation process. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Ancillary