聚脲相变微胶囊的制备及其应用性能研究
发布时间：2018-09-01 10:21
【摘要】：相变材料是在发生相转化过程中进行热量的储存和释放,从而实现对环境温度的调节和控制的材料。这类材料由于能解决能量供求在时间和空间上不匹配的矛盾,而成为国内外能量利用和材料科学方面研究的热点。相变材料的相变形式一般可分为固-固相变、固-液相变、液-气相变和固-气相变,后两种相变过程虽然可以储存较多热量,但因气体占有的体积大,使体系增大,设备复杂,使用起来极为困难,因此常被利用的相变过程有固-液、固-固相变两种类型。由于固-液相变材料在相变过程前后会产生表观相态变化等缺点,所以利用胶囊技术将具有特定熔点和结晶点的相变材料包裹到胶囊内部制备成蓄热调温胶囊成为近年来研究的一个热点。本文通过界面聚合法以油溶性单体TDI与水溶性单体DETA反应生成的聚脲树脂为壁材、正十八烷为芯材制备了聚脲树脂相变微胶囊。在微胶囊制备的乳化阶段,研究了油水相比、乳化转速和乳化时间对乳液乳化效果或微胶囊性能的影响,发现当油水相比为1:6,乳化转速为6000rpm、乳化时间为5min时,得到的乳液均一、稳定,制备的微胶囊粒径d90为3.25μm,即90%的微胶囊粒径在3.25μm以下。再分别以苯乙烯-马来酸酐共聚物钠盐(sma钠盐)、op-10和阿拉伯树胶为乳化剂制备微胶囊,并比较了不同乳化剂下制备得到微胶囊的粒径分布、表观形貌、储热性能和抗渗透性能。结果表明:与乳化剂sma钠盐和阿拉伯树胶相比,以op-10为乳化剂制备的相变微胶囊,虽表面较为粗糙、包覆率稍低,但粒径最小,在1-4μm左右,且分布均匀,具有良好的抗渗透性能。乳化剂的用量对胶囊的性能有重要的影响,当乳化剂op-10的浓度为8%时,所得微胶囊的粒径分布集中,平均粒径约为2μm,副产物较少。采用干重分析法来测定tdi与deta反应的最佳摩尔比,结果证实,deta与tdi反应时,最佳摩尔比为1.29:1。而控制不同的聚合反应时间,得到微胶囊的红外光谱图和sem图显示,不同聚合反应时间下制备得到的微胶囊的粒径都很均一、且大小差别不大,随着聚合反应时间的延长,生成的微胶囊数增多,成球率增加,得到的胶囊表面更为光滑、形状更规则,且反应进行3h时,反应物已完全反应。最后用dsc、ftir和tg等测试手段表征了最优操作条件下制备的聚脲树脂相变微胶囊的性能,通过ftir测试可初步证明壁材成功包裹芯材,tg测试表明,聚脲囊壁对囊芯正十八烷的挥发具有一定的阻滞作用,提高了正十八烷微胶囊的热稳定性,dsc测试数据显示,聚脲相变微胶囊的热焓值为95.81j/g,包裹效率为92.13%,这说明芯材正十八烷的利用率高,合成的聚脲相变微胶囊有一定的储热能力。为了检验聚脲树脂相变微胶囊和另一种自制的密胺树脂相变微胶囊对温度的调节作用,本论文通过浸渍法将相变微胶囊分别整理到仿丝棉絮片、喷胶棉絮片和七孔棉絮片上,并对整理前、后絮片的厚度、单位面积质量、表观形貌、保暖性和升温性能进行了测试表征。测试结果表明:整理后絮片纤维上的相变微胶囊有一定程度的聚集和结块,且絮片变薄,单位面积质量增加,保温率和质量折算保温率均有一定程度的提高。且经密胺树脂相变微胶囊整理后絮片的质量折算保温率均高于经聚脲树脂相变微胶囊整理后絮片,而厚度折算保温率变化不大抑或有所下降。整理前、后絮片的时间-温度曲线显示,升温过程中,整理前的絮片温度升高的幅度最大,其次为经聚脲树脂相变微胶囊整理后的絮片,经密胺树脂相变微胶囊整理后的絮片对温度的调节作用最为明显,同时也说明经自制的相变微胶囊整理后的絮片具有蓄热调温功能。
[Abstract]:Phase change materials (PCMs) are materials that store and release heat in the process of phase transformation, so as to realize the regulation and control of environmental temperature. Because of solving the contradiction between energy supply and demand in time and space, PCMs have become a hot spot in energy utilization and material science at home and abroad. The latter two kinds of phase change process can store more heat, but because of the large volume of gas, the system is enlarged, the equipment is complex, and it is very difficult to use. Therefore, the phase change process often used has two types: solid-liquid phase change and solid-solid phase change. In recent years, the preparation of heat storage and temperature-regulating capsules by encapsulating phase change materials with specific melting and crystallization points into capsules has become a hot spot. In this paper, oil-soluble monomer TDI and water-soluble monomer DETA were synthesized by interfacial polymerization. Polyurea resin was used as wall material. The phase change microcapsule of polyurea resin was prepared by using eighteen alkane as core material. The influence of emulsification speed and emulsification time on emulsion emulsification effect or microcapsule performance was studied in the emulsification stage of microencapsulation. It was found that when the oil and water was 1:6, the emulsification speed was 6000rpm, and the emulsification time was 5min. The obtained emulsions were uniform and stable. The diameter of the prepared microcapsules D90 was 3.25 m, that is, the diameter of 90% microcapsules was below 3.25 m. Microcapsules were prepared by using styrene maleic anhydride copolymer sodium salt (SMA sodium salt), OP-10 and Arabia gum as emulsifier respectively, and the particle size distribution and apparent appearance of microcapsules prepared under different emulsifying agents were compared. The results showed that, compared with the emulsifier SMA sodium salt and Arabic gum, the phase change microcapsules prepared with OP-10 as emulsifier had the smallest particle size, about 1-4 micron, uniform distribution and good permeability. The amount of emulsifier was important to the performance of the microcapsules. When the concentration of emulsifier OP-10 was 8%, the particle size distribution of the microcapsules was concentrated, the average particle size was about 2 micron, and the by-products were few. Infrared spectrum and SEM showed that the particle size of microcapsules prepared by different polymerization time were uniform, and the size difference was not significant. With the extension of polymerization time, the number of microcapsules increased, the pelletizing rate increased, the surface of the microcapsules was smoother, the shape of the microcapsules was more regular, and the reactants were completely reacted when the reaction lasted for 3 hours. Finally, the properties of the polyurea resin phase change microcapsules prepared under the optimal operating conditions were characterized by means of dsc, FTIR and tg. The results of FTIR showed that the core material was successfully wrapped by the wall material. The TG test showed that the polyurea capsule wall had a certain blocking effect on the volatilization of n-octadecane in the core and improved the thermal stability of n-octadecane microcapsules. DSC test data showed that the enthalpy of polyurea phase change microcapsules was 95.81j/g, and the encapsulation efficiency was 92.13%. This indicated that the core material n-octadecane had high utilization rate, and the synthesized polyurea phase change microcapsules had certain heat storage capacity. In this paper, phase change microcapsules were prepared on silk-like cotton wadding, gum-sprayed cotton wadding and seven-hole cotton wadding respectively by impregnation method. The thickness, unit area mass, surface morphology, thermal insulation and heating performance of the wadding before and after finishing were tested and characterized. Moreover, the mass conversion heat preservation rate and the mass conversion heat preservation rate of the treated flocs were higher than those of the treated flocs, and the thickness conversion heat preservation rate was not changed much or possibly. The time-temperature curves before and after finishing showed that during the heating process, the temperature of the floc before finishing increased the most, followed by the floc after the polyurea resin phase change microcapsule finishing, and the floc after the melamine resin phase change microcapsule finishing had the most obvious effect on the temperature regulation, which also showed that the self-made phase change was micro The floc after capsule finishing has the function of heat storage and temperature regulation.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB34
本文编号：2216901
[Abstract]:Phase change materials (PCMs) are materials that store and release heat in the process of phase transformation, so as to realize the regulation and control of environmental temperature. Because of solving the contradiction between energy supply and demand in time and space, PCMs have become a hot spot in energy utilization and material science at home and abroad. The latter two kinds of phase change process can store more heat, but because of the large volume of gas, the system is enlarged, the equipment is complex, and it is very difficult to use. Therefore, the phase change process often used has two types: solid-liquid phase change and solid-solid phase change. In recent years, the preparation of heat storage and temperature-regulating capsules by encapsulating phase change materials with specific melting and crystallization points into capsules has become a hot spot. In this paper, oil-soluble monomer TDI and water-soluble monomer DETA were synthesized by interfacial polymerization. Polyurea resin was used as wall material. The phase change microcapsule of polyurea resin was prepared by using eighteen alkane as core material. The influence of emulsification speed and emulsification time on emulsion emulsification effect or microcapsule performance was studied in the emulsification stage of microencapsulation. It was found that when the oil and water was 1:6, the emulsification speed was 6000rpm, and the emulsification time was 5min. The obtained emulsions were uniform and stable. The diameter of the prepared microcapsules D90 was 3.25 m, that is, the diameter of 90% microcapsules was below 3.25 m. Microcapsules were prepared by using styrene maleic anhydride copolymer sodium salt (SMA sodium salt), OP-10 and Arabia gum as emulsifier respectively, and the particle size distribution and apparent appearance of microcapsules prepared under different emulsifying agents were compared. The results showed that, compared with the emulsifier SMA sodium salt and Arabic gum, the phase change microcapsules prepared with OP-10 as emulsifier had the smallest particle size, about 1-4 micron, uniform distribution and good permeability. The amount of emulsifier was important to the performance of the microcapsules. When the concentration of emulsifier OP-10 was 8%, the particle size distribution of the microcapsules was concentrated, the average particle size was about 2 micron, and the by-products were few. Infrared spectrum and SEM showed that the particle size of microcapsules prepared by different polymerization time were uniform, and the size difference was not significant. With the extension of polymerization time, the number of microcapsules increased, the pelletizing rate increased, the surface of the microcapsules was smoother, the shape of the microcapsules was more regular, and the reactants were completely reacted when the reaction lasted for 3 hours. Finally, the properties of the polyurea resin phase change microcapsules prepared under the optimal operating conditions were characterized by means of dsc, FTIR and tg. The results of FTIR showed that the core material was successfully wrapped by the wall material. The TG test showed that the polyurea capsule wall had a certain blocking effect on the volatilization of n-octadecane in the core and improved the thermal stability of n-octadecane microcapsules. DSC test data showed that the enthalpy of polyurea phase change microcapsules was 95.81j/g, and the encapsulation efficiency was 92.13%. This indicated that the core material n-octadecane had high utilization rate, and the synthesized polyurea phase change microcapsules had certain heat storage capacity. In this paper, phase change microcapsules were prepared on silk-like cotton wadding, gum-sprayed cotton wadding and seven-hole cotton wadding respectively by impregnation method. The thickness, unit area mass, surface morphology, thermal insulation and heating performance of the wadding before and after finishing were tested and characterized. Moreover, the mass conversion heat preservation rate and the mass conversion heat preservation rate of the treated flocs were higher than those of the treated flocs, and the thickness conversion heat preservation rate was not changed much or possibly. The time-temperature curves before and after finishing showed that during the heating process, the temperature of the floc before finishing increased the most, followed by the floc after the polyurea resin phase change microcapsule finishing, and the floc after the melamine resin phase change microcapsule finishing had the most obvious effect on the temperature regulation, which also showed that the self-made phase change was micro The floc after capsule finishing has the function of heat storage and temperature regulation.
【学位授予单位】：东华大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TB34
【共引文献】
相关期刊论文 前1条
1 马艳杰;李伟;王建平;韩娜;张兴祥;;金属离子络合丙烯酸基聚合物微胶囊的研制[J];高分子材料科学与工程;2015年10期
相关博士学位论文 前2条
1 马艳红;相变温度可调的储能微胶囊的制备及其性能研究[D];清华大学;2013年
2 任屏源;纳米金属氧化物的制备及光催化和发光特性研究[D];兰州大学;2014年
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