超临界二氧化碳辅助阻燃聚合物加工及结构与性能关系研究

发布时间：2018-05-30 15:10

本文选题：超临界二氧化碳 + 膨胀型阻燃剂　；参考：《中北大学》2017年硕士论文

【摘要】：聚合物材料具有轻质、易于加工、价格低廉、综合性能优越等优点,广泛应用于汽车、建筑、包装、航天、军事等各个领域。然而,由于大多聚合物材料存在易燃性的问题,不仅限制其使用范围,而且由此引发的火灾会给人类社会带来重大的人员伤亡和经济损失等问题。此外,随着当今阻燃领域相应法规法令日渐苛刻及环保意识的加强,加强对聚合物的绿色高效阻燃研究尤为重要。超临界二氧化碳(scCO_2)具有绿色环保、来源广泛、价格便宜、易于回收等优点,广泛应用于食品、医药和化工等领域。当scCO_2溶解在聚合物基体中时,能够起增塑作用,增大聚合物的自由体积、大分子链活动能力、传质速率和降低熔体粘度等作用。然而,直到现在,scCO_2技术鲜有被提及用于阻燃领域。本论文旨在进一步扩大scCO_2技术的应用,研究scCO_2技术在改善阻燃剂在基体中分散状况的可行性,进而提高阻燃聚合物的阻燃效率,并探究cCO_2辅助阻燃剂分散的机理。本文的主要研究内容如下:(1)首先,本文采用scCO_2作为加工介质,研究膨胀型阻燃剂(IFR)在聚丙烯(PP)基体中的分散情况及其阻燃效率。其中,IFR由聚磷酸铵与季戊四醇构成,且重量比为3:1。研究结果表明:应用scCO_2技术能够有效改善IFR在PP中分散情况,通过调控scCO_2的含量能够实现在添加较低含量的IFR即可达到较高含量的IFR的阻燃效果,扩展了提高阻燃聚合物阻燃效率的方法。(2)其次,本文为了揭示scCO_2技术在辅助IFR在PP基体中分散的作用及提高复合材料阻燃效率的作用机理,研究了温度及压力对膨胀型阻燃聚丙烯加工及性能的影响。通过调节温度、压力等条件,研究了阻燃发泡PP复合材料的合适发泡条件,及不同条件下相应阻燃PP复合材料的分散状况及性能。研究结果表明:在合适发泡温度内,降低温度和增大压力有助于提高PP/IFR复合材料的膨胀倍率;采用scCO_2技术能够进一步优化IFR在PP基体中的分散,能够有效改善残炭质量和抑烟效果等,从而进一步提高了阻燃剂的阻燃效率。(3)最后,为了进一步扩展scCO_2技术在其它阻燃体系中的应用,采用CO_2作为发泡剂,通过大分子溴系阻燃剂(FR-122P)与溴化环氧树脂(2200HM)协效阻燃,研究了复合阻燃剂对聚苯乙烯(PS)和发泡PS复合材料的阻燃改性。研究结果表明:当FR-122P与2200HM重量比为4:1、且添加量为25wt%时,复合材料的极限氧指数可达25.8,并可通过UL-94V-0等级;当复合阻燃剂的添加量为40wt%时,可得到膨胀倍率较高、泡孔密度较大、泡孔尺寸较小的发泡PS复合材料,且可通过泡沫水平燃烧的HF-2等级。
[Abstract]:Polymer materials are widely used in automobile, construction, packaging, aerospace, military and other fields because of their advantages such as light weight, easy processing, low price, superior comprehensive performance and so on. However, due to the flammability of most polymer materials, not only the scope of their use is limited, but also the resulting fire will bring serious casualties and economic losses to human society. In addition, with the increasingly harsh laws and regulations in the field of flame retardancy and the strengthening of environmental awareness, it is particularly important to strengthen the study of green and efficient flame retardation of polymers. Supercritical carbon dioxide (SCCO _ 2) is widely used in food, medicine and chemical industry. When scCO_2 is dissolved in polymer matrix, it plays a role in plasticizing, increasing the free volume of polymer, the ability of macromolecular chain activity, mass transfer rate and reducing melt viscosity. Until now, however, scCO2 technology has rarely been mentioned in the flame retardant field. The purpose of this thesis is to further expand the application of scCO_2 technology, to study the feasibility of scCO_2 technology in improving the dispersion of flame retardants in matrix, and to improve the flame retardant efficiency of flame retardant polymers, and to explore the mechanism of dispersing flame retardants assisted by cCO_2. The main contents of this paper are as follows: firstly, the dispersion and flame retardant efficiency of intumescent flame retardant (scCO_2) in PP matrix were studied by using scCO_2 as processing medium. The IFR is composed of ammonium polyphosphate and pentaerythritol, and the weight ratio is 3: 1. The results showed that the dispersion of IFR in PP could be effectively improved by using scCO_2 technology, and the flame retardant effect of higher content of IFR could be achieved by controlling the content of scCO_2 by adding lower content of IFR. Secondly, in order to reveal the role of scCO_2 technology in assisting the dispersion of IFR in PP matrix and the mechanism of improving the flame retardant efficiency of composites, the method of increasing the flame retardant efficiency of flame retardant polymer is expanded. The effects of temperature and pressure on the processing and properties of intumescent flame retardant polypropylene were studied. By adjusting the temperature and pressure, the suitable foaming conditions of flame retardant foamed PP composites were studied, and the dispersion and properties of the corresponding flame retardant PP composites under different conditions were studied. The results show that the expansion rate of PP/IFR composites can be improved by lowering the temperature and increasing the pressure at the appropriate foaming temperature, and the dispersion of IFR in PP matrix can be further optimized by using scCO_2 technology. It can effectively improve the quality of carbon residuals and smoke suppression effect, thus further improving the flame retardant efficiency of flame retardant. Finally, in order to further expand the application of scCO_2 technology in other flame retardant systems, CO_2 is used as foaming agent. The flame retardant modification of polystyrene (PS) and foamed PS composites was studied by the synergistic flame retardation of macromolecular bromine flame retardant (FR-122P) and brominated epoxy resin (2200HM). The results show that when the weight ratio of FR-122P to 2200HM is 4: 1 and the addition amount is 25wt%, the limit oxygen index of the composite material can reach 25.8 and pass through the UL-94V-0 grade, and when the content of the composite flame retardant is 40wt%, the expansion ratio is higher and the pore density is larger. Foamed PS composites with smaller foam size and HF-2 grade that can be burned horizontally through foam.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TQ314.248

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