Chitin and waste shrimp shells liquefaction and liquefied products/polyvinyl alcohol blend membranes

Ball-milled chitin was liquefied with an optimal yield of 92% under sulfuric acid in diethylene glycol (DEG) at 160 degrees C for 120 min. The resulting liquid mixture was roughly separated into two portions: the real products of the reaction (liquefied ball-milled chitin, LBMC) and the remaining unreacted DEG. LBMC was further mingled with polyvinyl alcohol (PVA) to prepare LBMC/PVA blend membranes. To promote the direct utilization of shellfishery waste, raw shrimp shells were used to replace chitin for the liquefaction and membrane preparation operations. Liquefied ball-milled shrimp shells (LBMS) and the corresponding LBMS/PVA blend membranes were obtained. After adding LBMC or LBMS, the mechanical, thermal, water content and antibacterial performance of blend membranes were significantly improved compared to pure PVA membrane. Surprisingly, all the measured properties of LBMC/PVA and LBMS/PVA blend membranes were comparable, and even some properties of the latter were slightly superior than those of the former.