Eco-friendly surface modification on polyester fabrics by esterase treatment

Significance Statement

PET (polyethylene terephthalate) fiber is the most widely used synthetic fiber which accounts for nearly 80% of total synthetic fiber output. However, it is hydrophobic with low moisture permeation and stain removing ability, causing poor wear comfort. Alkali deweighting is the most commonly used method for PET modification in industry because of its low cost. However, the wastewater and heavy chemicals in the effluent cause enormous damage to the environment.

A new enzyme pretreatment technology for PET modification was developed, which is clean, economic, efficient and feasible in mild processing conditions (60 oC, pH 6.5). Cutinase is an {Alpha}/{Beta} hydrolase with high activity and low specificity for the degradation of polyester. The results confirmed that a large amount of carboxyl and hydroxyl groups were generated on the surface of polyester fibers after being hydrolyzed by cutinase. This process could be accelerated by increasing the cutinase concentration. The wettability of the fabric increased significantly with a better capillary effect (11.4 cm), a shorter wicking time (1.0 s) and a higher moisture regain (0.49%). In addition, the oily stain removability and resistance was greatly enhanced because of the improved hydrophilicity. This technology also has advantages in mechanical property maintenance, which relate to good wear durability. Cutinase treatment led to a smaller weight loss, better whiteness in appearance and better fiber integrity vs. a traditional alkali treatment. The crystallinity, surface topography (smoothness) and mechanical strength of cutinase treated fabric kept almost unchanged, while the alkali modified fabric became rougher and weaker. The crystallinity of the latter one decreased from 45.1% to 40.8% and the burst strength decreased from 800 N to nearly 600 N.

In conclusion, the cutinase pretreatment technology provides a great opportunity for the industry to produce hydrophilic polyester fabrics with improved wear comfort, better stain removal, but without significant damages to the mechanical performance of fabrics. It is an environment-friendly approach with a great potential to have a promising development prospects in industry.

 

 

Eco-friendly surface modification on polyester fabrics by esterase treatment

Applied Surface Science, Volume 295, 15 March 2014, Pages 150-157. 

Jindan Wu, Guoqiang Cai, Jinqiang Liu, Huayun Ge, Jiping Wang.

MOE Key Laboratory of Advanced Textile Materials & Manufacturing Technology, National Base for International Cooperation in Science & Technology of Textiles and Daily Chemistry, MOE Engineering Research Center for Eco-Dyeing and Finishing of Textiles, Zhejiang Sci-Tech University, Hangzhou, Zhejiang 310018, China

Abstract

Currently, traditional alkali deweighting technology is widely used to improve the hydrophilicity of polyester fabrics. However, the wastewater and heavy chemicals in the effluent cause enormous damage to the environment. Esterase treatment, which is feasible in mild conditions with high selectivity, can provide a clean and efficient way for polyester modification. Under the optimum conditions, the polyester fabric hydrolysis process of esterase had a linear kinetics. X-ray photoelectron spectrometry (XPS) results showed that hydroxyl and carboxyl groups were produced only on the surface of modified fiber without changing the chemical composition of the bulk. These fibers exhibited much improved fabric wicking, as well as greatly improved oily stain removal performance. Compared to the harsh alkali hydrolysis, the enzyme treatment led to smaller weight loss and better fiber integrity. The esterase treatment technology is promising to produce higher-quality polyester textiles with an environmental friendly approach.

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