机织层压类柔性复合材料界面粘接性能的研究

发布时间：2018-03-24 19:39

  本文选题：柔性复合材料　切入点：剥离强度　出处：《东华大学》2009年硕士论文

【摘要】： 以机织物为增强体的柔性复合材料具有较高的强度、模量及尺寸稳定性,在近几年里有了广阔的发展空间和应用前景,不仅广泛应用于汽车蓬盖,广告灯箱布,充气筏等领域,而且开始应用于环保的科技产品。 在实际使用过程中,我国柔性复合材料普遍存在界面剥离强度差的现象,尤其是层压和压延类产品,随着使用时间的推移经常会出现界面粘合不佳,甚至会出现增强基布与基体相分离的情况,致使产品力学性能降低,易吸湿,严重影响了其使用寿命,也制约了我国柔性复合材料在国际舞台的发展。因此,如何提高柔性复合材料界面的粘接强度即抗剥离性能,是值得关注和思考的一个紧迫问题。 本课题以涤纶平纹机织布为增强体,利用热熔层压将其与聚氯乙烯(PVC)薄膜复合,借鉴现有的界面粘合理论,根据影响界面粘接强度的三要素:润湿性、反应性、界面残余内应力,来研究如何提高涤纶增强基布与聚氯乙烯薄膜之间的界面粘接强度即抗剥离性能,最后本课题还研究了湿热老化对界面粘接性能的影响。 首先,针对涤纶增强基布表面的弱界面层和浸润性,研究不同前处理方法对柔性复合材料界面粘接性能的影响。研究表明:由于表面油剂杂质的去除,及表面粗糙程度增加,前处理不但提高了柔性复合材料界面剥离强度,而且提高了其拉伸强度,但劣化了其撕裂性能。 对于以机织物为增强体的柔性复合材料,底涂工艺粘合剂的使用必不可少。结合数学方法,对底涂工艺中增粘助剂做了较为详尽的实验分析,并对底涂工艺进行了优化设计。研究表明:增粘助剂用量、底涂层的烘培温度、烘培时间对界面剥离强度都有不同程度的影响,影响程度从大到小为:增粘助剂用量＞烘培时间＞烘培温度。通过正交试验法,得到最佳组合方案为:增粘助剂用量2.0%,烘培时间40s,烘培温度140℃。 从减小界面残余内应力为出发点,在底涂工艺中加入改性碳酸钙来降低膨胀系数。利用硬脂酸对碳酸钙进行超声波改性,通过吸油值,沉降指数,活化指数,接触角来考察改性效果,最终确定硬脂酸改性的最佳用量为2.0%。改性碳酸钙不但能够增强其界面剥离强度,而且具有“增韧补强”的效果。 最后研究了不同的介质溶液及热空气老化对柔性复合材料界面粘接性能的影响。研究表明:高温能够加速柔性复合材料在不同介质中的老化,并且介质的种类和属性也能影响其界面的粘接强度。不同温度的热空气老化对界面粘接效果也有不同程度的影响。 本文所做的工作及得到的一些结论有助于柔性复合材料界面性能的研究,并对实际生产具有一定的参考价值。
[Abstract]:Flexible composites with woven fabrics as reinforcements have high strength, modulus and dimensional stability, and have a wide development space and application prospects in recent years. They are not only widely used in automobile canopy, advertising lamp-box cloth, inflatable raft and other fields. And began to apply to environmental protection technology products. In the process of practical use, the phenomenon of poor interfacial peeling strength is common in flexible composites in China, especially for laminated and calendered products. With the development of service time, the interface adhesion is often poor. There will even be the separation of the reinforced substrates from the matrix, which will result in the decrease of the mechanical properties of the products, the easy moisture absorption, the serious influence on their service life, and the restriction of the development of the flexible composites in China on the international stage. It is an urgent problem that how to improve the adhesion strength of the interface of flexible composites, that is, the anti-peeling property. In this paper, polyester plain looms are used as reinforcements, which are combined with polyvinyl chloride (PVC) PVC films by hot melt lamination, and the three factors that affect the interfacial bonding strength: wettability and reactivity are used for reference. The interfacial residual stress was used to study how to improve the interfacial adhesion strength between polyester reinforced fabric and PVC film. Finally, the effect of wet-heat aging on the interfacial adhesion property was also studied. Firstly, in view of the weak interfacial layer and wettability on the surface of polyester reinforced substrate, the effect of different pretreatment methods on the interface adhesion properties of flexible composites is studied. The results show that due to the removal of surface oil impurities and the increase of surface roughness, The pretreatment not only improves the interface peeling strength, but also improves the tensile strength of the flexible composite, but it degrades its tear strength. For flexible composites with woven fabric as reinforcements, the use of adhesive in bottom coating process is essential. In combination with mathematical method, a detailed experimental analysis is made on the tackifying agent in the bottom coating process. The optimum design of the bottom coating process was carried out. The results showed that the amount of tackifying agent, the baking temperature and the drying time of the bottom coating had different effects on the peeling strength of the interface. The influence degree from big to small is as follows: dosage of tackifying agent > baking time > drying temperature. By orthogonal test, the optimum combination scheme is: dosage of viscosity promoter 2.0, baking time 40 s, baking temperature 140 鈩，

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