Project title: Artificial Leathers

 

Project group members:

Pornwasu Pongtheerawan

Arada Sungkanit

Tanpitcha Phongchaipaiboon

Suratpittaya School

 

            To solve a number of problems (such as high cost, short lifetime usage and fragility) currently associated with the use of real or artificial leathers in Thai industries, we have planned to inexpensively develop artificial leathers from cellulose produced by Acetobactor xylinum, using wastes from pineapple and rambutan as main culture materials. In this project, we proposed to conduct six related experiments; 1) Finding an optimal formula of culture media and optimal time for media sterilization; 2) Finding optimum time for biological production of cellulose from A. xylinum; 3) Finding the optimum method and time for drying the cellulose parchments and to study characteristics of dry cellulose parchments (thickness of the dry parchments and the resistant strength); 4) Evaluation of the quality (such as tensile strength and water absorption) of the cellulose parchments cross-linked with rambutan husk extracts compared with that of the uncross-linked parchments; 5) Comparison of tensile strengths and price of the cellulose-based artificial leathers with the commercialized leathers; and 6) Production of shadow puppets, hats, handbags, and other products from the dried, cross-linked cellulose.  The results showed that the suitable liquid culture was the mixture of 500 ml of pineapple husks extract and 500 ml of coconut juices with 1.5 ml of acetic acid, 5 g of ammonium sulfate and 25 g of cane sugar. This mixture gave the thickest cellulose gel whit smooth skin compared to Cellulose obtained from culture with other formula. The culture medium needed to be boiled for at least 30 minutes for sterilization. The cellulose gels of usuable sizes were produced in 7 days of culture at room temperature. The gel parchments needed to be heated at 80°C for 30 hours and were tanned naturally using rambutan husks extract to increase their mechanical strength. Their average tensile modulus was at 32.03 MPa, Which is (≈ 64.46%) higher than the untanned parchment. The tanned parchment is slightly less strong (approximately 14% lower tensile modulus). Than genuine leather, while cost 70% less, than that of the genuine leather. Results from these experiments will be useful to local shadow puppets manufacturers and other leather users. In addition to their environmentally friendly property, this cellulose-based leather can potentially be further developed into various kinds of leather-substitute products such as souvenir bags and hats.