原位聚合预浸料制备研究毕业论文
2021-04-21 23:03:03
摘 要
预浸料成型工艺是一种十分重要的复合材料生产工艺。传统的环氧树脂用于预浸料成型时,由于其固化温度较高,而且耗时长,耗能大,所以成型工艺效率比较低。如果使用热塑性树脂例如酚氧树脂快速成型,由于其分子量非常大,所以对纤维的浸润效果较差,不易形成良好的界面结合。因此,研究制备具有良好界面结合性能且能够快速冲压成型的预浸料具有格外重要的意义。
本文通过一些梯度比例的两种一元胺,即糠胺(2-呋喃甲胺)与苯胺,分别对E-51环氧树脂原位聚合扩链,形成具有较高分子量的线型酚氧树脂预浸料,并成型为复合材料,分别以差式扫描量热法(DSC)、动态热机械分析(DMA)、拉伸性能测试、弯曲性能测试研究两种不同扩链体系以及扩链比(环氧树脂与一元胺的摩尔比)对原位聚合温度,成型温度,玻璃化转变温度及力学性能等的影响。研究结果如下:
通过对糠胺、苯胺分别对E-51环氧树脂扩链的反应进行理论计算,研究了产物分子量与配方的理论关系,发现聚合产物分子量随胺比例的上升而先提高后降低,且变化率也先提高后降低。
通过DSC扫描研究了聚合反应的反应温度,并设计了温度控制方案。糠胺/E-51体系设置常温反应4h,100℃下反应2h;苯胺/E-51体系设置120℃下反应4h,175℃反应2h。
通过DSC与DMA分别研究了聚合产物的玻璃化转变温度,即原位聚合预浸料的二次加工温度。当配方中一元胺的比例增加时,聚合物的玻璃化转变温度先增加后降低,糠胺体系100:24,苯胺体系100:26两组配方分别具有最高的玻璃化转变温度。糠胺/E-51体系聚合产物酚氧树脂的玻璃化转变过程发生在30-60℃之间,而苯胺/E-51体系聚合产物的玻璃化转变过程发生在65-105℃之间,相对较高。苯胺与环氧树脂原位聚合制备的复合材料使用温度较高,应用范围可能更广。
通过DMA研究了各组配方制备复合材料的储能模量。其中糠胺体系100:20、苯胺体系100:26的配方分别具有最高的储能模量。
通过拉伸与弯曲试验研究了各组配方制备复合材料板材的力学性能,糠胺体系100:24、苯胺体系100:26两组配方分别具有最高的拉伸强度与模量、弯曲强度与模量,糠胺100:24组接近,而苯胺100:26组高于直接以酚氧树脂溶液法制备预浸料生产的复合材料板材的力学性能。在加入一元胺的量逐渐增加的过程中,复合材料的力学性能整体上出现先提高后降低的趋势,与理论计算分子量的结果相符。
关键词: 预浸料;原位聚合;酚氧树脂;热机械性能
Abstract
Prepreg molding is a very important production process of composite materials. The most frequently-used epoxy resin has high curing temperature, long reaction time, high energy consumption and low efficiency of forming process when it’s used in prepreg molding. If we use thermoplastic resin such as phenoxy resin instead of epoxy resin in punch forming to improve the efficiency of forming process, it’s still a problem that it is really hard for thermoplastic resin to soap in fibers and form a good interface combination.Therefore, it is of great significance to study the prepreg with good interface bonding performance and the ability of rapid punch forming.
In this article, we use some gradient ratio of two kinds of monoamin, namely the chaff amine (2 - furan methylamine) and aniline, to compound high molecular weight linear phenoxy resin material and form composite materials by polymerization of E - 51 epoxy resin chain extender in situ, respectively by Differential Scanning Calorimetry (DSC), Dynamic thermal Mechanical analysis (DMA) and tensile properties test, bending performance test study of two different extender chain system as well as chain extender than (the molar ratio of epoxy resin and monoamin) on in situ polymerization temperature, mold temperature and glass transition temperature and mechanical properties of impact. The results of the study are as following:
We studied the relationship between the product molecular weight and the formula of theory. We found that the product molecular weight as the rise of the proportion of monoamin and reduce after improve the first, and the lower rate increase after the first.
The reaction temperature of polymerization was studied by DSC scanning and the temperature control scheme was designed.Chaff amine/E - 51 system set at room temperature, 4 h reaction, reaction 2 h under 100 ℃.Aniline/E - 51 system set up the reaction of 4 h under 120 ℃, 175 ℃ reaction 2 h.
By DSC and DMA, the glass transition temperature of polymerized products, i.e. the secondary processing temperature of in-situ polymerized preleaching materials, was studied respectively. As the proportion of formula monoamin increase polymer glass transition temperature increases after the first reduce, chaff amine system 100:24, aniline system, 100:26 formula, respectively, the two groups have the highest glass transition temperature.Chaff amine/E - 51 system oxygen product of phenol resin glass transition process occurs between 30 to 60 ℃, and aniline polymerization product/E - 51 system of glass transition occurs between 65-105 ℃, relatively high.The composite materials prepared by in-situ polymerization of aniline and epoxy resin have higher temperature and wider application.
The energy storage modulus of composite materials prepared by various formulations was studied by DMA. The formula of chaff amine system 100:20 and aniline system 100:26 have the highest energy storage modulus respectively.
Each formula is studied through tensile and bending test preparation, the mechanical properties of composite sheet, chaff amine system 100:24 and aniline system, 100:26 formula, respectively, the two groups have the highest tensile strength and modulus, bending strength and modulus, chaff amine 100:24 groups close to, and aniline, 100:26 group is higher than directly to phenoxy resin solution prepared in material production, the mechanical properties of the composite sheet.In the process of increasing the amount of monoamin, the mechanical properties of composite materials as a whole tend to increase first and then decrease, which is consistent with the results of theoretical calculation of molecular weight.
Key Words: Prepreg; in situ polymerization; Phenoxy resin; Thermal mechanical properties
目录
第1章 绪论 1
1.1 引言 1
1.2 树脂基复合材料简介 1
1.3 预浸料成型工艺 2
1.3.1 溶液法 2
1.3.2 热熔法 3
1.3.3 胶膜法 3
1.4 酚氧树脂简介 3
1.5 原位聚合反应 5
1.6 研究目标与研究思路 7
第2章 实验与测试方法 8
2.1 前言 8
2.2 实验部分 8
2.2.1 实验药品 8
2.2.2 实验仪器 9
2.2.3 原位聚合酚氧树脂预浸料的制备 9
2.3 测试与表征 10
第3章 结果与讨论 11
3.1 产物分子量计算 11
3.2 DSC测试 12
3.2.1 聚合反应DSC曲线 12
3.2.2 DSC测量Tg 13
3.3 DMA测试 14
3.4 机械性能测试 15
第4章 结 论 17
参考文献 18
致谢 20
第1章 绪论
1.1 引言
人类进步的历史与人类对材料的应用历史有着密切的联系,随着时代的飞速发展,在许多高新技术领域,甚至是人们的生活中,一些原有的材料渐渐地开始不能满足人们日益增长的需求,所以人们研究了将两种或两种以上的材料用某种工艺方式混合到一起,制备出新的复合材料。复合材料的出现和迅速发展是材料设计方面的一个巨大突破。预浸料成型则是复合材料成型的一种应用非常广泛,十分重要的成型工艺。
预浸料是用树脂基体在严格控制的条件下浸渍连续纤维或编织物,再经过一定的处理过程制备的一种储存备用的半成品,是制造复合材料的中间材料。截至本世纪初,超过70%的复合材料制品都是通过预浸料工艺成型制备的。随着对复合材料高性能的需求与日俱增,各界学者对快速固化,长储存期,高性能预浸料的开发与应用也日渐广泛。复合材料预浸料及成型是未来复合材料领域的一个重要的发展方向,能满足高效率成型的预浸料是研究重点。