童鞋论文网专业提供代写本科论文、代写硕士论文、代写职称论文、代写毕业论文、论文发表等服务,上万成功案例,欢迎咨询。 网站地图  |  加入收藏  |  设为首页
童鞋论文网
热门搜索
行政 教育 营销 法律 经济 护理 心理 会计 文学 工商 计算机 旅游
站内搜索:
童鞋论文网
 当前位置:童鞋论文网 > 硕士论文 > 文章正文
 
β-环糊精包合物的制备及其在环氧树脂阻燃中的应用
论文作者:童鞋论文网  论文来源:www.txlunwenw.com  发布时间:2019/9/3 9:46:49  

摘要:环氧树脂(EP)是一种耐腐蚀性强,电绝缘性能突出和粘接性能卓越的热固性聚合物,在航天航空,胶黏剂,涂料,电子电器,交通运输等领域被广泛应用。然而,纯EP材料的易燃性大大限制了其应用范围。因此,对EP进行阻燃改性具有重要意义。生物质炭源β-环糊精(β-CD)具有低廉的价格,可再生的性能,优良的成炭性能,其具有独特的分子空腔,能够容纳尺寸匹配的客体分子形成包合物。为了解决传统不可再生成炭剂的日益匮乏和当前阻燃EP的阻燃效率低和热稳定性下降等问题,本论文选择β-CD为成炭剂,制备了β-CD包合物,通过固化工艺将其添加到EP中制备EP复合材料,研究EP/β-CD包合物复合材料的热稳定性和阻燃性能,并探讨β-CD包合物的阻燃机理,主要研究工作如下:

(1)采用饱和水溶液法,以β-CD为主体,间苯二酚双(二苯基)磷酸酯(RDP)为客体,成功制备β-CD与RDP的包合物(β-CD@RDP)。将β-CD@RDP添加到EP基体中制备EP复合材料。热失重测试(TGA)结果表明,β-CD@RDP能够有效提高EP基体达到最大热降解(分解)速率时对应的温度,且呈现出良好的成炭性能。当β-CD@RDP的添加量为20wt%时,EP复合材料的极限氧指数(LOI)值提高到26.5%,垂直燃烧(UL-94)测试达到V-1级别;锥形量热(CONE)测试结果表明,此添加量的EP复合材料的热释放速率峰值(PHRR),总释放热量(THR)及总生烟量(TSP)均大幅减小。当EP/β-CD@RDP被加热时,β-CD具有作为碳源和泡沫形成剂的优点,而RDP能够原位产生磷酸,促进成炭。对CONE测试后的残炭进行分析,发现β-CD@RDP的加入能够使EP复合材料燃烧后的炭渣形成致密连续,强度高的炭层结构,这种结构阻止了氧气和热量向内层基体传递。因此,β-CD@RDP能够有效抑制EP的可燃性。

(2)由于β-CD@RDP中RDP的含量很少,导致其添加量为25wt%时,EP复合材料的UL-94级别只达到V-1级别,因此有必要调整实验方案,进一步提高EP材料的阻燃性能。二茂铁(FE)是一种具有芳香族性质的有机过渡金属化合物,已有研究证实FE在聚合物中具有抑烟作用,因此将FE应用于EP阻燃,有望得到较好的效果。本文利用β-CD独特的分子空腔,以β-CD为主体,FE为客体制备了β-CD@FE包合物,两者在包合物中的摩尔比例为β-CD:FE=1:1。将β-CD@FE作为成炭剂与RDP复配应用于EP阻燃中。TGA结果表明,此复配阻燃剂能够有效提高EP基体达到最大热降解(分解)速率时对应的温度,且呈现出良好的成炭性能。复配阻燃剂为20wt%的添加量时,EP复合材料的LOI值提高到35.0%,UL-94垂直燃烧测试达到V-0级别;CONE测试结果表明此添加量能使EP的PHRR和THR分别降低29.9%和29.1%,且TSP降低11.5%。β-CD@FE和RDP复配能够增加EP复合材料在燃烧过程中的成炭量,改善膨胀保护炭层的微观结构,提高炭层的致密性和体系的热稳定性,从而更好的保护基体,有效提高EP的阻燃和抑烟性能,FE的引入具有协同阻燃作用。

(3)介孔中空二氧化硅(HMS)在燃烧过程中可以保持骨架稳定,起到保护炭层的作用,其较大的比表面积和介孔中空结构能够有效吸附EP材料燃烧过程中产生的烟气。本文以聚苯乙烯(PS)为中空结构模板,十六烷基三甲基溴化铵(CTAB)为介孔模板,成功制备了介孔有序,尺寸均一,形貌良好的单分散球形HMS,其比表面积和孔体积分别为367.63m2/g和0.21cm3/g,介孔尺寸约为2.28nm。通过静电吸附,层层组装法制备以HMS为核,β-CD@FE为壳的核-壳型复合微球β-CD@FE@HMS,并制备了EP/β-CD@FE@HMS复合材料,研究EP复合材料的热稳定性和阻燃性能。TGA分析表明,β-CD@FE@HMS能够有效提高EP的初始分解(降解)温度和EP基体达到最大热分解(降解)速率时对应的温度,并且复合材料拥有良好的成炭性能。β-CD@FE@HMS添加量仅为5wt%时,EP复合材料的LOI提高至27.5%,UL-94等级达到V-1级别。CONE测试结果表明此添加量的EP复合材料能使EP的PHRR和THR值分别降低11.0%和12.3%,且TSP降低30.6%。利用扫描电镜(SEM)和拉曼光谱分析(Raman)等手段进一步证实了β-CD@FE与HMS的协同效应。β-CD@FE能够促使EP基体在燃烧时形成致密,石墨化程度高的炭层;利用热失重/红外联用(TG/FTIR)证实了HMS能利用自身独特的迷宫效应减少挥发性气体的逸出,起到阻燃和抑烟效果。

Epoxy resin (EP) is a thermosetting polymer with strong corrosion resistance, outstanding electrical insulation properties and excellent bonding properties. It is widely used in aerospace, adhesives, coatings, electronics, transportation and other fields. However, the flammability of pure EP materials greatly limits the range of applications. Therefore, it is important to modify the flame retardant of EP. The biomass carbon source β-cyclodextrin (β-CD) has low cost, reproducible performance, and excellent char forming performance, and has a unique molecular cavity to accommodate a size-matched guest molecule to form a clathrate. In order to solve the problem of the lack of traditional non-renewable carbonaceous agents and the low flame retardant efficiency and thermal stability of current flame retardant EP, this paper selects β-CD as a carbon-forming agent and prepares β-CD inclusion compound. EP composites were prepared bycuring process. The thermal stability and flame retardant properties of EP/β-CD inclusion composites are studied. The flame retardant mechanism of β-CD inclusion complexes is discussed. The main research work is as follows:

(1) Using saturated aqueous solution method, β-CD as the subject and resorcinol bis(diphenyl)phosphate (RDP) as the guest, successfully prepared inclusion complex of β-CD and RDP (β-CD@RDP). And EP composite was prepared by adding β-CD@RDP to an EP matrix. The results of the thermogravimetric test (TGA) show that β-CD@RDP can effectively increase the corresponding temperature of the EP matrix to reach the maximum thermal degradation (decomposition) rate, and exhibits good char forming performance. When the addition amount of β-CD@RDP is 20wt%, the limit oxygen index (LOI) value of the EP composite is increased to 26.5%, and the vertical combustion (UL-94) test reaches the V-1 level; the results of the cone calorimetry (CONE)test show that the peak heat release rate (PHRR), total heat release (THR) and total smoke generation (TSP)of EP composites are greatly reduced. When EP/β-CD@RDP is heated, β-CD has the advantage of being a carbon source and a foam former, and RDP is capable of generating phosphoric acid in situ to promote char formation. The carbon residue after the CONE test was analyzed. It was found that the addition of β-CD@RDP can form a dense continuous and high-strength carbon layer structure of the carbon residue after burning of the EP composite. This structure prevents oxygen and heat from passing to the inner matrix. Therefore, β-CD@RDP can effectively suppress the flammability of EP.

(2) Since the content of RDP in β-CD@RDP is small, when the addition of β-CD@RDP was 25 wt%, the UL-94 grade of the EP composite only reaches the V-1 level, so it is necessary to adjust the experimental scheme to further improve the flame retardant properties of the EP material. Ferrocene (FE) is an organic transition metal compound with aromatic properties. It has been confirmed that FE has a smoke suppressing effect in polymers. Therefore, the application of FE to EP flame retardant is expected to have better effects. In this paper, β-CD@FE inclusion complex was prepared,β-CD was the subject and FEwas the guest, and the molar ratio of the two in the inclusion complex was β-CD:FE=1:1. β-CD@FE was used as a carbon-forming agent in combination with RDP in EP flame retardant. The TGA results show that the compound flame retardant can effectively increase the corresponding temperature of the EP matrix to reach the maximum thermal degradation (decomposition) rate, and exhibits good char forming performance. When the compound flame retardant is added in an amount of 20wt%, the LOI value of the EP composite increased to 35.0%, and the UL-94 vertical burning test reached the V-0 level; the CONE test results show that the added amount can make the PHRR and THR of the EP reduced by 29.9% and 29.1%, respectively, and the TSP was reduced by 11.5%.

关键词:环氧树脂;β-环糊精包合物;阻燃性能;热稳定性能;成炭剂

epoxy resin;β-cyclodextrin inclusion complex; flame retardation; thermal stability; carbonific

上一篇:女子举重运动员主要运动损伤部位、原因及预防措施研究     下一篇:Pt基一维纳米材料的可控合成及其电催化研究
 
论文客服 95702844
论文热线18796337551
本站网址 www.txlunwenw.com
郑重承诺 原创,包修改,包通过!
童鞋论文网真诚欢迎新老客户的光临与惠顾!
 
 热门文章
· 住宅建设用地使用权续期研究
· 用户锁定效应视角下的网易云音
· 众筹产品创新性对融资绩效的影
· 南京市城镇居民冷鲜肉认知度问
· 摩拜共享单车可持续盈利研究
· 催生地方政府隐性债务风险的原
· 社交媒体中不实信息转发主体心
· 基于网络平台的SPA模式研究——
· 基于游客感知的云台山景区微信
· 新媒体时代背景下乡村旅游企业
 
 推荐文章
· 论商业性小屏直播的主持互动策
· 新兴偶像经济发展现状及发展建
· 辅助线在小学生空间观念培育中
· 罗浮山国家级风景名胜区探险旅
· 基于《预算法》的地方政府债务
· 商品房买卖合同“霸王条款”存
· 中泰水果贸易竞争力比较分析
· 我国企业内部转移价格应用现状
· 虚拟现实技术下的创意短片《萌
· 核定征税与查账征税实施现状及
 
 相关文章
· 非国家行为体的影响及其限度研
· 雷蒙德·威廉斯的生态社会主义
· 麦金太尔正义理论思想渊源研究
· 论做好硕士研究生的引路人
· 新时期研究生学术活动研究
· “石发”与文学创作之关系研究
· 我国男装奢侈品消费市场探讨
· 关于张家山汉简所显示的汉初法
· 旅客冲击跑道事件的法律评析
· 离不了婚的新郎——我国婚姻登

论文原创,准时交稿,包修改,包通过,八年信誉,品质保证
童鞋论文网提供代写本科论文,代写专科论文,代写毕业论文,代写职称论文,代写硕士论文,论文发表及查重服务
备案号:苏ICP备11011187号-1 苏公网安备32030502000117号
版权归童鞋论文网所有 禁止一切商用盗用