本文選題：相變材料 + 微膠囊��； 參考：《西安工程大學(xué)》2015年碩士論文

【摘要】：聚脲微膠囊相變材料由于囊壁中不含有甲醛等有害成分而受到越來越多研究人員的關(guān)注,但傳統(tǒng)的聚脲囊壁大多都是采用芳香族二元異氰酸酯和脂肪族二元伯胺反應(yīng)制備的,由于芳香族異氰酸酯與脂肪族伯胺之間的反應(yīng)速率非�？烨倚纬傻木垭迥冶跒槎�性結(jié)構(gòu),因而所形成的囊壁熱穩(wěn)定性和致密性較差,使其應(yīng)用受到很大限制。本文通過選用反應(yīng)速率相對較小的脂肪族二異氰酸酯與制備三元網(wǎng)狀結(jié)構(gòu)囊壁兩種途徑相結(jié)合制備了系列高致密性微膠囊相變材料。分別采用光學(xué)顯微鏡、掃描電鏡(SEM)、差式掃描量熱儀(DSC)、紅外光譜(FTIR)和熱重分析儀(TGA)對所制備微膠囊相變材料的表面形貌、儲熱性能、化學(xué)結(jié)構(gòu)和熱穩(wěn)定性進行了研究和分析。一方面,以硬脂酸丁酯為芯材,苯乙烯馬來酸酐共聚物(SMA)為乳化劑,以異佛爾酮二異氰酸酯(IPDI)和二乙烯三胺(DETA)聚合形成的聚脲樹脂為壁材制備微膠囊相變材料,并探討了在反應(yīng)體系中加入單體2,4甲苯-二異氰酸酯(TDI)后對所制備微膠囊的表面形貌和熱穩(wěn)定性等性能的影響。結(jié)果表明,采用SMA作為乳化劑可以明顯地改善微膠囊的團聚現(xiàn)象,且在較少用量和較短的時間內(nèi)便可獲得良好的乳化效果。SEM分析表明,所制備微膠囊顆粒大小均一,呈球形分布,表面凹陷現(xiàn)象嚴重,加入TDI后可使表面凹陷現(xiàn)象得到改善。DSC分析表明,所制備微膠囊的熔融溫度為29.8℃,熔融熱焓為89.5J·g㧟1,儲熱性能良好,結(jié)晶曲線出現(xiàn)雙放熱峰,過冷現(xiàn)象明顯。TG結(jié)果顯示,當芯材壁材比為3:1,分別以IPDI和以IPDI/TDI混合物為異氰酸酯時,所制備微膠囊的耐熱溫度分別為207℃和227℃。隨著芯材壁材比的降低、TDI用量的增大、攪拌轉(zhuǎn)速的提高,微膠囊的耐熱穩(wěn)定性提高。另一方面,采用三官能度的丙三醇對所制備的聚脲囊壁進行改性,制備了具有三元網(wǎng)狀結(jié)構(gòu)囊壁的致密性優(yōu)良的微膠囊相變材料,研究了丙三醇加入方式和丙三醇與DETA質(zhì)量比對微膠囊表面形貌和熱穩(wěn)定性等性能的影響。SEM結(jié)果表明,丙三醇的加入使得所制備微膠囊的表面凹陷情況得到了明顯地改善,且丙三醇的用量越高,表面凹陷越少。丙三醇的加入方式對所制備微膠囊的熱穩(wěn)定性具有一定的影響,當DETA與丙三醇先后加入時微膠囊的熱穩(wěn)定性比兩者同時加入時要高。TG分析表明,加入丙三醇后所制備的三元網(wǎng)狀結(jié)構(gòu)囊壁微膠囊具有良好的熱穩(wěn)定性和致密性,其耐熱溫度由未改性時的227℃提高至240℃。
[Abstract]:Polyurea microencapsulated phase change materials have attracted more and more attention due to the absence of formaldehyde and other harmful components in the capsule wall. However, most of the traditional polyurea capsule walls are prepared by the reaction of aromatic diisocyanate and aliphatic binary primary amine. Because the reaction rate between aromatic isocyanate and aliphatic primary amine is very fast and the polyurea cyst wall is of binary linear structure, the thermal stability and compactness of the formed polyurea cyst wall are poor, which limits its application. In this paper, a series of phase change materials with high density microcapsules were prepared by combining aliphatic diisocyanate with ternary reticular structure. The surface morphology, thermal storage property, chemical structure and thermal stability of the microencapsulated phase change materials were studied by optical microscope, scanning electron microscope (SEM), differential scanning calorimeter (DSC), FTIR (FTIR) and thermogravimetric analyzer (TGA). On the one hand, using butyl stearate as core material, styrene maleic anhydride copolymer (SMA) as emulsifier, polyurea resin polymerized with isophorone diisocyanate (IPDIA) and diethylenetriamine (DETAA) as wall material, microencapsulated phase change materials were prepared. The effects of the addition of monomer 2O4 toluene-diisocyanate (TDI) into the reaction system on the surface morphology and thermal stability of the microcapsules were investigated. The results showed that the agglomeration of microcapsules could be obviously improved by using SMA as emulsifier, and a good emulsifying effect could be obtained in less dosage and shorter time. The results show that the melting temperature of the microcapsules is 29.8 鈩，

本文編號：1785496