英语翻译摘 要PVA薄膜是一种用途广泛的水溶性高分子材料,具有良好的透明性和韧性,阻隔性和保香性能极佳,是一种很有发展前

英语翻译
摘 要
PVA薄膜是一种用途广泛的水溶性高分子材料,具有良好的透明性和韧性,阻隔性和保香性能极佳,是一种很有发展前景的绿色包装材料,但由于PVA分子中含有大量的羟基,易与水分子中的羟基形成氢键,导致耐水性能很差,应用受到了很大的限制.本课题分析了目前改进聚乙烯醇耐水性研究成果中的优缺点,选用了尿素和硼酸做为改性剂提高聚乙烯醇的耐水性,实验中分别使用了不同量的尿素和硼酸对聚乙烯醇进行改性,用测试薄膜溶解率和溶胀率的方法,确定了耐水性最佳的共混膜中尿素和硼酸的用量,然后通过对比的方法分析了尿素和硼酸对聚乙烯醇的改性效果,得出了尿素对聚乙烯醇薄膜耐水性的改性效果优于硼酸的结论,分别对尿素改性聚乙烯醇耐水性薄膜和硼酸改性聚乙烯醇耐水性薄膜进行力学性能的测试,分析测试结果,得出改性剂用量对改性薄膜力学性能（拉伸性能、断裂伸长率、撕裂度）的影响.
关键词：PVA；耐水性；尿素；硼酸

Abstract：
PVA film is widely used as a kind of water soluble polymer material, transparent and has good toughness, resistance and excellent performance of the sweet, is a kind of green packaging material is very promising, but due to the PVA molecule contains a large number of hydroxyl, easy to form hydrogen bond with the hydroxyl radical in the water molecules, resulting in water resistance is poor, limits the application of. This paper analyzes the shortcoming of water resistance of PVA research results, using urea and boric acid to improve the water resistance of polyvinyl alcohol modifier, experiments are used in modification of polyvinyl alcohol with different amount of urea and boric acid, by the measurement of thin film dissolution rate and swelling ratio, urea and boric acid water the best of the blend film dosage were determined, and then through the method of comparison analysis of the modification effect of urea and boric acid on the polyvinyl alcohol, the urea on the modification effect is better than that of boric acid polyvinyl alcohol film water resistance of urea modified theory, water resistance of PVA film and mechanical properties of Modified PVA boric acid water film test, analysis of test results, the amount of the modifier modified film mechanical properties (tensile strength, elongation at break, tear strength) effect.
Keywords: PVA; water resistance; urea; boric acid