聚脲相變微膠囊的制備及其應(yīng)用性能研究
發(fā)布時(shí)間：2018-09-01 10:21
【摘要】：相變材料是在發(fā)生相轉(zhuǎn)化過程中進(jìn)行熱量的儲(chǔ)存和釋放,從而實(shí)現(xiàn)對環(huán)境溫度的調(diào)節(jié)和控制的材料。這類材料由于能解決能量供求在時(shí)間和空間上不匹配的矛盾,而成為國內(nèi)外能量利用和材料科學(xué)方面研究的熱點(diǎn)。相變材料的相變形式一般可分為固-固相變、固-液相變、液-氣相變和固-氣相變,后兩種相變過程雖然可以儲(chǔ)存較多熱量,但因氣體占有的體積大,使體系增大,設(shè)備復(fù)雜,使用起來極為困難,因此常被利用的相變過程有固-液、固-固相變兩種類型。由于固-液相變材料在相變過程前后會(huì)產(chǎn)生表觀相態(tài)變化等缺點(diǎn),所以利用膠囊技術(shù)將具有特定熔點(diǎn)和結(jié)晶點(diǎn)的相變材料包裹到膠囊內(nèi)部制備成蓄熱調(diào)溫膠囊成為近年來研究的一個(gè)熱點(diǎn)。本文通過界面聚合法以油溶性單體TDI與水溶性單體DETA反應(yīng)生成的聚脲樹脂為壁材、正十八烷為芯材制備了聚脲樹脂相變微膠囊。在微膠囊制備的乳化階段,研究了油水相比、乳化轉(zhuǎn)速和乳化時(shí)間對乳液乳化效果或微膠囊性能的影響,發(fā)現(xiàn)當(dāng)油水相比為1:6,乳化轉(zhuǎn)速為6000rpm、乳化時(shí)間為5min時(shí),得到的乳液均一、穩(wěn)定,制備的微膠囊粒徑d90為3.25μm,即90%的微膠囊粒徑在3.25μm以下。再分別以苯乙烯-馬來酸酐共聚物鈉鹽(sma鈉鹽)、op-10和阿拉伯樹膠為乳化劑制備微膠囊,并比較了不同乳化劑下制備得到微膠囊的粒徑分布、表觀形貌、儲(chǔ)熱性能和抗?jié)B透性能。結(jié)果表明:與乳化劑sma鈉鹽和阿拉伯樹膠相比,以op-10為乳化劑制備的相變微膠囊,雖表面較為粗糙、包覆率稍低,但粒徑最小,在1-4μm左右,且分布均勻,具有良好的抗?jié)B透性能。乳化劑的用量對膠囊的性能有重要的影響,當(dāng)乳化劑op-10的濃度為8%時(shí),所得微膠囊的粒徑分布集中,平均粒徑約為2μm,副產(chǎn)物較少。采用干重分析法來測定tdi與deta反應(yīng)的最佳摩爾比,結(jié)果證實(shí),deta與tdi反應(yīng)時(shí),最佳摩爾比為1.29:1。而控制不同的聚合反應(yīng)時(shí)間,得到微膠囊的紅外光譜圖和sem圖顯示,不同聚合反應(yīng)時(shí)間下制備得到的微膠囊的粒徑都很均一、且大小差別不大,隨著聚合反應(yīng)時(shí)間的延長,生成的微膠囊數(shù)增多,成球率增加,得到的膠囊表面更為光滑、形狀更規(guī)則,且反應(yīng)進(jìn)行3h時(shí),反應(yīng)物已完全反應(yīng)。最后用dsc、ftir和tg等測試手段表征了最優(yōu)操作條件下制備的聚脲樹脂相變微膠囊的性能,通過ftir測試可初步證明壁材成功包裹芯材,tg測試表明,聚脲囊壁對囊芯正十八烷的揮發(fā)具有一定的阻滯作用,提高了正十八烷微膠囊的熱穩(wěn)定性,dsc測試數(shù)據(jù)顯示,聚脲相變微膠囊的熱焓值為95.81j/g,包裹效率為92.13%,這說明芯材正十八烷的利用率高,合成的聚脲相變微膠囊有一定的儲(chǔ)熱能力。為了檢驗(yàn)聚脲樹脂相變微膠囊和另一種自制的密胺樹脂相變微膠囊對溫度的調(diào)節(jié)作用,本論文通過浸漬法將相變微膠囊分別整理到仿絲棉絮片、噴膠棉絮片和七孔棉絮片上,并對整理前、后絮片的厚度、單位面積質(zhì)量、表觀形貌、保暖性和升溫性能進(jìn)行了測試表征。測試結(jié)果表明:整理后絮片纖維上的相變微膠囊有一定程度的聚集和結(jié)塊,且絮片變薄,單位面積質(zhì)量增加,保溫率和質(zhì)量折算保溫率均有一定程度的提高。且經(jīng)密胺樹脂相變微膠囊整理后絮片的質(zhì)量折算保溫率均高于經(jīng)聚脲樹脂相變微膠囊整理后絮片,而厚度折算保溫率變化不大抑或有所下降。整理前、后絮片的時(shí)間-溫度曲線顯示,升溫過程中,整理前的絮片溫度升高的幅度最大,其次為經(jīng)聚脲樹脂相變微膠囊整理后的絮片,經(jīng)密胺樹脂相變微膠囊整理后的絮片對溫度的調(diào)節(jié)作用最為明顯,同時(shí)也說明經(jīng)自制的相變微膠囊整理后的絮片具有蓄熱調(diào)溫功能。
[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.
【學(xué)位授予單位】：東華大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TB34
本文編號：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.
【學(xué)位授予單位】：東華大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TB34
【共引文獻(xiàn)】
相關(guān)期刊論文 前1條
1 馬艷杰;李偉;王建平;韓娜;張興祥;;金屬離子絡(luò)合丙烯酸基聚合物微膠囊的研制[J];高分子材料科學(xué)與工程;2015年10期
相關(guān)博士學(xué)位論文 前2條
1 馬艷紅;相變溫度可調(diào)的儲(chǔ)能微膠囊的制備及其性能研究[D];清華大學(xué);2013年
2 任屏源;納米金屬氧化物的制備及光催化和發(fā)光特性研究[D];蘭州大學(xué);2014年
，本文編號：2216901
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