气相二氧化硅改性不饱和聚酯树脂研究

发布时间：2018-10-29 20:48

【摘要】：复合材料中,不饱和聚酯树脂(UPR)是使用量最大的树脂品种之一,在结构、防腐、绝缘材料等领域有广泛的应用。但通用的不饱和聚酯树脂仍存在一些不足,如固化后硬而脆,韧性差,强度低等,故其应用场合受到极大的限制,因此,对不饱和聚酯树脂进行改性具有重要意义。通常,改性后不饱和聚酯树脂的触变性高低对其施工具有重要影响,获得优异触变性的不饱和聚酯树脂一直是其改性的热点。气相二氧化硅具有纳米颗粒尺度和丰富的表面羟基,是高分子材料优选的补强剂和触变剂。本论文采用气相二氧化硅改性不饱和聚酯树脂,通过配方及工艺优化,对比国产与进口气相二氧化硅之间差异,制备出满足客户使用要求的新型不饱和聚酯。论文首先研究了多种型号气相二氧化硅的物化性质,包括填充密度、比表面积、离散度、粒子形态、红外光谱等,在此基础上,研究气相二氧化硅型号及含量、分散速度、分散时间、苯乙烯单体含量对不饱和聚酯树脂触变性及树脂浇铸体力学性能的影响。结果表明,随着气相二氧化硅用量的增加,不饱和聚酯树脂触变性显著增加,不同型号气相二氧化硅对不饱和聚酯树脂触变性影响强弱顺序为:N-20HL-200MHL-200A-200HL-150;作为不饱和聚酯树脂的交联剂与稀释剂,苯乙烯不仅可降低体系的粘度,还能改善体系的触变性,随着苯乙烯用量的增加,不饱和聚酯树脂的触变性明显增大。不饱和聚酯树脂的拉伸强度和弹性模量随着气相二氧化硅用量、分散时间、分散速度的增加而增大,断裂伸长率则正好相反,不同型号气相二氧化硅对不饱和聚酯树脂的增强效果大小顺序为:N-20HL-200MHL-200A-200HL-150;随着苯乙烯含量的增加,不饱和聚酯树脂的拉伸强度和断裂伸长率先快速增加,当含量超过32.5%时,拉伸强度逐渐下降,断裂伸长率则缓慢上升;拉伸断面的SEM分析发现,气相二氧化硅颗粒粒径较小,且在树脂基体中分散较为均匀,断面呈现韧性断裂。
[Abstract]:Unsaturated polyester resin (UPR) is one of the most widely used resins in composite materials. It is widely used in the fields of structure, anticorrosion, insulation and so on. But the general unsaturated polyester resin still has some shortcomings, such as hard and brittle after curing, poor toughness, low strength, so its application is greatly limited. Therefore, it is of great significance to modify unsaturated polyester resin. Generally, the thixotropy of the modified unsaturated polyester resin has an important effect on its construction, and obtaining excellent thixotropic unsaturated polyester resin has always been the focus of its modification. Gas phase silica is a kind of reinforcing agent and thixotropic agent for polymer materials because of its nanometer particle size and abundant surface hydroxyl groups. In this paper, the unsaturated polyester resin modified by gas phase silica was used. By optimizing the formula and process, a new type of unsaturated polyester was prepared by comparing the difference between domestic and imported gas phase silica. Firstly, the physical and chemical properties of various types of gas phase silica are studied, including filling density, specific surface area, dispersion, particle morphology, infrared spectrum and so on. The influence of dispersing time, styrene monomer content on thixotropy of unsaturated polyester resin and mechanical properties of resin casting. The results show that the thixotropy of unsaturated polyester resin increases with the increase of the amount of gas phase silica. The order of thixotropy of unsaturated polyester resin with different types of gas phase silica is N-20HL-200MHL-200A-200HL-150; As the crosslinking agent and diluent of unsaturated polyester resin, styrene can not only reduce the viscosity of the system, but also improve the thixotropy of the system. With the increase of the amount of styrene, the thixotropy of unsaturated polyester resin increases obviously. The tensile strength and elastic modulus of unsaturated polyester resin increase with the increase of the amount of gas phase silica, dispersing time and dispersing speed, but the elongation at break is just the opposite. The order of reinforcing effect of different types of gas phase silica on unsaturated polyester resin is N-20HL-200MHL-200A-200HL-150; With the increase of styrene content, the tensile strength and elongation at break of unsaturated polyester resin first increase rapidly. When the content exceeds 32.5, the tensile strength decreases gradually, and the elongation at break increases slowly. The SEM analysis of tensile fracture shows that the particle size of gas phase silica is small and dispersed uniformly in the resin matrix, and the fracture of the section is ductile.
【学位授予单位】：华南理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ323.4;TQ127.2

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