Chitosan based green polymers

• Main Author: Chong, Wei Kai
• Other Authors: Hu Xiao
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Materials
• Online Access: https://hdl.handle.net/10356/138890
• Institution: Nanyang Technological University

Chitosan are natural biodegradable polymers extracted from the hard-outer skeleton of shellfish. It has a flocculant property that can be used for wastewater treatment. Such particle fillers are of considerable interest to engineering and polymer industries. Over the years, industries have been making use of such fillers with polymer matrix to develop efficient products known as chitosan cryogels, CS to improve the olden technology. Cryogels which have highly interconnected and porous structure, enables high water absorbing capacity with fast swelling behaviour. Furthermore, it is reusable by squeezing out the absorbed water from the cryogels. However, very limited work has been done on the effect with additional of different crosslinkers (poly (ethylene glycol) diacrylate, PEGDA and glutaraldehyde) and without crosslinkers would affect the mechanical robustness of CS to its water treatment properties. Against this background, the present research work has been undertaken to synthesize CS by cryo-polymerizing using different molecular weight, MW chitosan and to determine the effect on its mechanical behaviour. It was found out that CS with ultra-high MW chitosan, UHMW can be further analyse with crosslinking process and mechanical and dye absorption analysis of 5ppm methyl orange. Different weight percentage, wt% variables such as PEGDA concentration (1.23wt%, 2.44wt%, 9.09wt% and 16.67wt%), glutaraldehyde concentration (5wt% and 10wt%) and UHMW CS without crosslinkers were used to compare the characteristics performance. The effects of each variable on the performance of the cryogel were evaluated in terms of swelling ratio SR, compression test, chemical bonding, dye absorption test and morphology study. It was then found out that CS with 10wt% glutaraldehyde was very effective in dye absorption of 97.24% and was further analysed for dye absorption using different dyes (brilliant, methylene and rhodamine) with 5ppm and 10ppm concentration. This report also compares the SEM images and mechanical properties between different CS.