Preparation and characterization of poly(methyl methacrylate-co-divinylbenzene) microcapsules containing phase change temperature adjustable binary core materials

A series of phase change temperature adjustable microencapsulated phase change materials (micro-PCMs) were prepared by in situ polymerization method. The micro-PCMs possessed butyl stearate and paraffin as binary core materials, and poly(methyl methacrylate-co-divinylbenzene) (PMMA-co-DVB) copolymer as shell material. More importantly, compared with the conventional micro-PCMs, the binary core materials rendered the micro-PCMs a phase change temperature adjustable property by regulating the weight ratio of butyl stearate to paraffin. Scanning electron microscopy (SEM) photographs showed that micro-PCMs had relatively spherical profiles and compact surfaces with diameter ranging from 5-10 mu m. Differential scanning calorimetry (DSC) results indicated that the binary core content in micro-PCMs was in a high range of 50-85%. Besides, these as-prepared micro-PCMs showed excellent thermal stability and they decomposed in two steps at considerably high temperatures above 200 degrees C. (C) 2012 Elsevier Ltd. All rights reserved.