Poly(lactic acid)/Biodegradable Polymer Blend for The Preparation of Flat-Sheet Membrane

Abstract

Biodegradable polymers have been more attractive for membrane materials, especially poly(lactic acid) (PLA) because they degrade in natural environment after use. In this study, the membranes were developed from a polymer blend of PLA and other biodegradable polymers, such as poly(butylene succinate) (PBS), poly(butylene adipate-co-terphthalate) (PBAT) and Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). The membranes were formed via nonsolvent induced phase separation process using n-methyl-2-pyrrolidone (NMP) as a solvent and water as a nonsolvent. The pure water flux and BSA rejection were tested to determine the filtration performance of membranes. The microstructures and tensile strength of membranes were characterized by field emission scanning electron microscope (FE-SEM) and universal testing machine (UTM), respectively. All of membranes appeared finger-like and sponge-like structures in cross-section, and porous structure on surface. PLA/PHBV blend membranes had pure water flux and BSA rejection as high as PLA/PBS and PLA/PBAT blend membranes. The pure water flux and BSA rejection of the blend ratio (PLA/PHBV/NMP) of 15:1:84 were 65 l/m2•h and 79%, respectively.

Advances in biopolymer-based membrane preparation and applications

“…PHBV has recently been used in combination with PLA to form novel blended membranes 118,119 . By mixing these two polymers, the resulting membranes had improved strength and ductility compared to pure PHBV membranes 120 .…”

“…At the same time the natural degradation time could be decreased, which in some applications might be too long for membranes made only with PHBV. Keawsupsak et al 119 prepared biodegradable membranes for water treatment using PLA blended with PBS, PBAT or PHBV via non-solvent induced phase separation using NMP as a solvent and water as a non-solvent.…”

Microfiltration and Ultrafiltration Membranes for Water Purification

“…PHB is the most common PHA produced by fermentation by bacteria like Alcaligenes, Azobacter, Bacillus and Pseudomonas [47]. PLA and PHBV have been combined in a recently developed procedure to synthesize novel blended membranes [57,58]. The membranes synthesized by the mixture of PLA and PHBV had increased strength and ductility when compared to membranes synthesized from only PHBV.…”

“…Biodegradable membrane for the purpose of water treatment was synthesized by Keawsupsak et al [58] by blending PLA with PBAT, PHBV or PBS via non solvent (water) induced phase separation. PHB has restrictive use as a polymer owing to its high crystallinity and brittleness.…”