Formulation and characterization of bilayer films based on Brea gum and Pectin

Abstract The formulation of bilayer films is a strategy aimed at combining the advantages and properties of different film-forming materials. Bilayer films based on pectin and brea gum were formulated and their functional properties studied and compared with those presented by single layer films of each component. The micrographs and surface properties confirmed that the bilayer films can maintain their identity and prevent delamination. The mechanical properties of the films depended on the characteristics of the polymers and their interactions, and the bilayer films showed prevalence of the brea gum properties. The brea gum films showed high solubility that influenced the bilayer film solubility. The water vapour permeability of the bilayer films was dependent on the material that was exposed to the side where desorption occurred. The bilayer films presented lower water vapour permeability than the brea gum films but higher than that of pectin films of similar thicknesses. The differential properties of each layer of bilayer films make them potentially interesting for controlled drug release.摘要 本研究提出的双层膜（bilayer films）制备策略，旨在整合不同成膜材料的优势与性能。本研究制备了基于果胶（pectin）与松脂胶（brea gum）的双层膜，对其功能特性开展研究，并与各组分的单层膜性能进行对比。显微图像与表面性能分析结果证实，该双层膜可保持各自结构特性，且能有效防止分层现象。薄膜的力学性能取决于聚合物自身特性及其相互作用，且双层膜更凸显松脂胶的性能特征。松脂胶膜具有较高的溶解性，该特性会对双层膜的溶解性产生影响。双层膜的水蒸气透过率（water vapour permeability）取决于其朝向解吸发生一侧的材料组成。相较于同厚度的松脂胶膜，双层膜的水蒸气透过率更低，但高于同厚度的果胶膜。双层膜各层的差异化特性使其在控释给药（controlled drug release）领域具备潜在应用价值。