GPTMS-Montmorillonite-filled biopolymer chitosan membrane with improved compatibility, physicochemical, and thermal stability properties

Abstract

The chitosan/organo-montmorillonite (Ch/O-MMT) membrane was fabricated and tested. Surface modification of O-MMT particles using 3-glicydoxy propyl trimethoxysilane (GPTMS) to enhance its compatibility with chitosan is presented. The resulting composite membrane was characterized by using SEM, AFM, and FTIR to observe the morphological and functional group structure. The crystallinity, thermal stability, and mechanical strength was analyzed by XRD, TGA, and tensile test.The results suggested that the modification of MMT using GPTMS could increase the compatibility of O-MMT with chitosan membrane, thus producing a good composite membrane with well-dispersed MMT filler within the chitosan polymer matrices. Based on the FTIR analysis, the presence of GPTMS could improve the interaction between chitosan and O-MMT material, thus forming more hydrogen bonding with chitosan membrane than Ch/MMT membrane. The TGA curve analysis showed that the addition of inorganic filler into chitosan organic matrices was able to increase the thermal stability of Ch/MMT and Ch/O-MMT composite membrane, suggested to mechanical strength analysis. The improvement in thermal stability was due to the absence of hydrogen bonding formations between chitosan polymer and O-MMT filler. In addition, greater hydrogen bonding formation would lead to the tighter packing of Ch/O-MMT composite membrane, resulting in higher bonding strength and higher thermal resistance. All of the characterization results confirmed that the Ch/O-MMT composite membrane has better physicochemical properties than Ch/MMT composite membrane.