制备条件对癸酸-硬脂酸相变微胶囊性能的影响

Effect of Preparation Conditions on Properties of Capric Acid-Stearic Acid Phase Transformation Microcapsules

为制备相变温度适用于建筑领域,热性能良好、包覆率高的相变微胶囊,以最低理论共融点配比下制备的复合癸酸-硬脂酸作为芯材,甲基丙烯酸甲酯(MMA)为壁材单体,十二烷基磺酸钠与吐温40作为乳化剂,偶氮二异丁腈作为引发剂,采用原位聚合的方式制备癸酸-硬脂酸相变微胶囊。探究不同聚合条件对相变微胶囊的表观形貌、粒径、热学性能、热稳定性的影响。结果表明,在选用季戊四醇三丙烯酸酯(PETA)作为交联剂,并选取MMA∶PETA质量比=7∶3,芯壁比3∶2,反应温度70℃,反应时间4 h的条件下制备出的相变微胶囊较为理想,包覆率达62.66%,产率达到90.28%,颗粒均匀、平均粒径为81.7μm,熔融焓达82.26 J/g,热稳定性良好。

In order to prepare the phase change microcapsules with good thermal performance and high coating rate,the composite capric acid-stearic acid prepared under the ratio of the lowest theoretical eutectic point was used as the core material,methyl methacrylate(MMA)as the wall material monomer,sodium dodecyl sulfonate with 0.23∶0.27 ratio of twain 40 as the emulsifier,and azodiisobutyronitrile as the initiator was used in situ preparation of capric acid-stearic acid phase change microcapsules.The influence of different polymerization conditions on the apparent morphology,particle size,thermal properties and stability were investigated.The results show when pentaerythritol triacrylate(PETA)is selected as the crosslinking agent,allyl methacrylate is configured with a ratio of 7∶3,the core wall ratio is 3∶2,and the reaction temperature is 70 ℃,under the condition of reaction time of 4 h.The phase change microcapsules prepared are ideal,the coating rate is 62.66%,the yield is 90.28%,the average particle size is 81.7 μm,the enthalpy of melting is 82.26 J/g,and the thermal stability is good.