低温碱脲溶解制备再生纤维素复合膜及其应用

Preparation and properties of regenerated cellulose composite membrane by dissolution in alkali/urea system at low temperature

采用低温碱脲体系溶解棉浆纤维素,并复配以纯丙或苯丙乳液,利用乙醇再生制备纤维素复合水凝胶,再热压诱导高分子聚集态结构转变,构建复合改性纤维素膜材料。结果表明,树脂复配制得的纤维素复合膜比纯纤维素膜在尺寸稳定性、拉伸性能、表面疏水性、溶胀性等方面均有所改善。当树脂复配率为10%时,复合膜的拉伸性能最好,且纯丙改性比苯丙改性的效果更优,纯丙改性纤维素膜的断裂强力较纯纤维素膜的提升94.4%,断裂伸长率提高33.7%。改性纤维素膜的表面疏水性能随树脂复配率增大而增强,溶胀率随复配率提高而降低,其中纯丙改性膜的性能改善幅度比苯丙改性膜更高。当纯丙树脂复配率为50%时,所成膜材料的表面水滴接触角达79.3°,水溶胀率降至40.8%。无论改性与否纤维素膜的表观物理结构均较为紧密,其中10%纯丙改性复合膜的表面更为光滑、致密。

The cotton pulp cellulose is dissolved in alkaline/urea system at low-temperature and mixed with pure acrylic or styrene acrylic emulsion.The cellulose composite hydrogels are prepared by ethanol regeneration,and then the polymer aggregation structure is transformed by hot pressing to form com?posite modified cellulose membrane materials.The results show that the size stability,tensile property,surface hydrophobicity and swelling property of the composite film are improved.When the composite ratio of resin is 10%,the tensile property of composite membrane is the best,and the effect of pure acrylic modification is better than that of styrene acrylic modification.The breaking strength and elonga?tion at break of pure acrylic modified cellulose membrane are increased by 94.4%and 33.7%respective?ly.The surface hydrophobicity of the modified cellulose membrane increases with the increase of the resin compounding ratio,and the swelling ratio decreases with the increase of the compounding ratio.The performance improvement of the pure acrylic modified membrane is higher than that of the styrene acrylic modified membrane.When the compounding ratio of the pure acrylic resin is 50%,the contact an?gle of the water drop on the surface of the film material reaches 79.3%,and the swelling ratio of the wa?ter decreases to 40.8%.Whether the cellulose membrane is modified or not,its apparent physical struc?ture is relatively close,and the surface of composite membrane modified by 10%pure acrylic is more smooth and compact.