Abstract:

In this paper,first,microencapsulated phase change materials were synthesized by the in-situ polymerization,with urea-formaldehyde resin as the shell and with RT31 paraffin as the core.Next,the effects of different emulsifiers on the morphology and thermal properties of the microcapsules were analyzed by means of SEM,DSC and optical microscopy.Then,the average particle size and its distribution as well as the thermal properties of the microcapsules at different emulsifier dosages and rotation speeds were analyzed. Finally, the morphology of the microcapsules varying with the acidification time was observed. Experimental results show that, when the complex emulsifier is composed of 52% （mass fraction, the same below） Tween 60 and 48% Span 60, the microcapsules made from 5% complex emulsifier at the rotation speed of 3000r/min are of uniform particle size, smooth and well- sealed surface, a phase-change temperature of 303.10K, a latent heat-storage capability of 63.85 J/g and an average particle size of 9.32 μm, and that the optimal acidification time for microcapsule synthesis is 90 min.

Key words: in-situ polymerization, microcapsule, phase change material, synthesis, property