Topographical changes in polyester after chemical, physical and enzymatic hydrolysis

Abstract

Polyester was treated with alkali, VUV excimer, and a hydrolytic enzyme. The effect of each treatment on the physicochemical properties of polyester (PET) was studied and compared by qualitative and quantitative methods. Scanning electron microscopy and atomic force microscopy analysis show that alkali treatment causes severe fiber degradation with formation of pits on the fabric surface. In contrast, excimer treatment results in uniform pitting at nanometer level, which is restricted to the surface. In case of enzyme-treated samples, non-uniform roughness was observed due to deposition of residual protein formed due to enzyme hydrolysis. K/S value and moisture regain value of excimer-treated samples were found to be higher than alkali- or enzyme-treated PET. Out of the three methods, excimer treatment appears to be the best method for PET modification with maximum number of polar groups being created on hydrolysis with marginal loss in strength and weight.

Keywords:

• polyester
• surface functionalization
• topographical analysis
• enzyme treatment

Acknowledgement

We would like to thank Department of Biotechnology, Ministry of Textiles for providing us the financial support to carry out the analytical tests. We would also like to acknowledge the inputs provided by Prof. M.N. Gupta, Department of Chemistry, Indian Institute of Technology, Delhi for enzymatic treatment.