Preparation of poly (n-butyl acrylate-co-methyl methacrylate) particles encapsulated with chitosan

Abstract

This research studied the preparation of copolymers containing soft and hard monomers, n-butyl acrylate (n-BA) and methyl methacrylate (MMA), respectively. The effect of monomer ratio, molecular weight, and concentration of chitosan on colloidal and film properties of the copolymer particles was investigated. The result showed that the percentage of monomer conversion was achieved at high conversion (approximately 85-90%). TEM micrographs of the copolymer particles and the copolymer particles encapsulated with chitosan showed that the particles obtained were spherical. The chitosan layer seemed to gain more thickness according to the molecular weight and concentration of chitosan. Measurements of particles size and surface charge of the copolymer encapsulated with chitosan indicated that the large size of particles were formed and positive charge was present on the particle surface when the chitosan was added. The chemical structure of the copolymer particles encapsulated with chitosan was characterized by ¹H-NMR in which % grafting of copolymers depended on the concentration and molecular weights of chitosan. The viscosity and surface tension of the encapsulated particles were increased when the chitosan content was increased from 0.5-1.5 %w/v. As the chitosan concentration was increased, the AFM micrographs exhibited that the roughness of copolymers was decreased. The result of bending test revealed the flexibility of the coating obtained from the encapsulated particles.