【作者】 汤兆宾；

【导师】 苏致兴；

【作者基本信息】 兰州大学 ， 高分子化学与物理， 2009， 博士

【摘要】 二氧化碳是主要的温室气体,作为主要温室气体的CO₂的排放量正以每年4%的速率递增,这给人类的生产、生活造成了严重的影响。在“原子经济”、“可持续发展”和“绿色化学”的潮流下,如何在相对温和的条件下实现CO₂的化学固定成为国际上竞相研发的热点课题。近年来,有关五元环状碳酸酯的合成研究已经成为了国内外学术界的研究热点,并且引起了人们的高度重视,本论文主要运用二氧化碳气体与环氧化合物开展了五元环状碳酸酯的合成工作并运用合成的单体进行了开环聚合反应。五元环状碳酸酯具有非常好的电绝缘性能,光学性能,合成成本低,环保等多种优点,预计五元环状碳酸酯的合成以及运用五元环状碳酸酯开发新型高分子材料在未来的研究中会有非常好的前景。本文,在自己对单体合成以及聚合研究的基础上,对聚碳酸酯/无机复合材料制备方面做了一定的探讨与研究。在五元环状碳酸酯的合成与聚合工作中:主要合成了B5CC和五元环状碳酸丙烯酯两种单体;B5CC单体与1,6-己二胺进行共聚反应;在五元环状碳酸酯与二胺的开环聚合的基础上,又采用五元环状碳酸丙烯酯为封端剂,研究了封端聚合一些性能的变化:加入不同量的封端剂以后,可以得到不同分子量的聚碳酸酯;随着封端剂加入比例的增大,得到的聚碳酸酯的分子量降低,并且玻璃化转变温度以及热稳定性也随之降低。本文在复合材料研究方面,制备了二氧化硅/聚碳酸酯、埃洛石/聚碳酸酯纳米复合材料;同时以蛭石为原料制备了聚碳酸酯/蛭石插层复合材料以及聚碳酸酯/剥离型蛭石复合材料。在二氧化硅、埃洛石/聚碳酸酯复合材料的制备研究中,首先对二氧化硅、埃洛石两种粒子表面进行有机化处理,然后通过原位聚合法制备了两种复合材料。复合后的材料不但使聚碳酸酯的热稳定性能得到了一定的提高,同时二氧化硅和埃洛石纳米粒子在有机溶剂中的分散性能也得到了明显的改善,纳米粒子本身有比较大的比表面积,比较容易发生团聚,接枝聚合以后明显地减少了粒子之间的团聚现象。在蛭石复合材料的研究方面,本文主要采取了两种方式制备聚碳酸酯/蛭石复合材料:聚碳酸酯/蛭石插层复合材料以及聚碳酸酯/剥离型蛭石复合材料。聚碳酸酯/蛭石插层复合材料与聚碳酸酯/剥离型蛭石复合材料两者相比,剥离型蛭石复合材料对热性能的影响稍好于插层方法所得到的复合材料。另外,通过扫描电镜的观察,可以看出两种方法制得的复合材料中,蛭石都能够很好地被剥离,并且能够比较均一地分散到聚合物当中。更多还原

【Abstract】 Carbon dioxide is the main greenhouse gas.With the increasing of the discharging of carbon dioxide as the main greenhouse gas,our life and the production have been affected.We all pay attention to make good use of the carbon dioxide under mild condition.In recent years,much attention has been paid to five-membered cyclic carbonates because of their extraordinarily high optical and thermal properties.In our paper, five-membered cyclic carbonates can be prepared from oxiranes and carbon dioxide under mild conditions.The prospect is extremely good to prepare some advanced materials with the five-membered cyclic carbonates in the future.In our paper,firstly,we synthesized the five-membered cyclic carbonates based on a wide variety of cyclic compounds and we also prepared the polymerization with the synthesized cyclic carbonates.Five-membered cyclic carbonates can react with diamine.So we prepare the polymers by the reaction theory.Based on the theory,we can change the Molecular weight by adjusting the ratio of the blocked compounds and also research the change of the properties.With the increasing of the ratio of the blocked compounds,the molecular weight is decreasing,and the glass transition temperature is also decreasing.The thermal decomposition is decreasing with the increasing of the ratio of the blocked compounds.In our work,we also prepared the inorganic particles/PHU nanocomposites, SiO₂/PHU,halloysite/PHU,Vermiculite/PHU and exfoliated vermiculite/PHU nanocomposites,etc.In the processing of preparing SiO₂/PHU,halloysite/PHU nanocomposites,firstly, the nanocompositewas prepared by the in situ surface-initiated polymerization of a five-membered cyclic carbonate,2,2-bi[p-（1,3-dioxolan-2-one-4-yl-methoxy）phenyl] propane（B5CC） and hexamethylene diamine,from the surfaces of the aminopropyl nanoparticle.s The thermal decomposition behavior of the polymers was evaluated by TGA. When the inorganic particles were added into the polymers,thermal decomposition behavior of the polymers was increasing,and the aggregates of the particles were better.We also prepared two kinds of vermiculites/PHU nanocomposites in our paper by intercalating and exfoliating vermiculite.Comparing with the two kinds of composites,the results of the latter is better on the thermal decomposition.The pristine vermiculites can be exfoliated by the two kinds of ways and can also dispersed well.更多还原