Department of Materials Engineering, University of São Paulo, 13566-590 São Carlos, SP, Brazil.
Biomacromolecules. 2011 Apr 11;12(4):907-14. doi: 10.1021/bm101227q. Epub 2011 Mar 1.
Ternary compatible blends of chitosan, poly(vinyl alcohol), and poly(lactic acid) were prepared by an oil-in-water (O/W) emulsion process. Solutions of chitosan in aqueous acetic acid, poly(vinyl alcohol) (PVA) in water, and poly(lactic acid) (PLA) in chloroform were blended with a high-shear mixer. PVA was used as an emulsifier to stabilize the emulsion and to reduce the interfacial tension between the solid polymers in the blends produced. It proved to work very well because the emulsions were stable for periods of days or weeks and compatible blends were obtained when PVA was added. This effect was attributed to a synergistic effect of PVA and chitosan because the binary blends PVA/PLA and chitosan/PLA were completely incompatible. The blends were characterized by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermal mechanical analysis (TMA), stress-strain tests, and Fourier transform infrared spectroscopy (FTIR). The results indicated that despite the fact that the system contained distinct phases some degree of molecular miscibility occurred when the three components were present in the blend.
壳聚糖、聚乙烯醇和聚乳酸的三元共混物通过油包水（O/W）乳液工艺制备。壳聚糖在醋酸水溶液、聚乙烯醇（PVA）在水中和聚乳酸（PLA）在氯仿中的溶液在高剪切混合器中混合。PVA 用作乳化剂来稳定乳液并降低共混物中固体聚合物之间的界面张力。事实证明它的效果非常好，因为乳液可以稳定数天或数周，并且当添加 PVA 时可以获得相容的共混物。这种效果归因于 PVA 和壳聚糖的协同效应，因为二元共混物 PVA/PLA 和壳聚糖/PLA 完全不相容。通过扫描电子显微镜（SEM）、差示扫描量热法（DSC）、热机械分析（TMA）、拉伸试验和傅里叶变换红外光谱（FTIR）对共混物进行了表征。结果表明，尽管该体系含有明显的不同相，但当三种成分存在于共混物中时，仍会发生一定程度的分子混溶性。
