| At present, the wall material of microcapsule phase change material is mainly the melamine resin, urea formaldehyde resin and other materials, these wall material as the structure of the problem itself, in the process of using micro capsules release harmful gases such as formaldehyde; the core material of microcapsule are single phase change materials,microencapsulation of single phase change material, the phase change temperature range is narrow, these disadvantages limit the applications of phase change materials. This paper selects the formaldehyde-free harmful gases such as styrene and methacrylic acid polymer as the wall material, respectively is are cetane with butyl stearate, cetane and oct-adecane as core materials, the preparation of the composite phase change material microcapsule composite phase change materials.This paper adopts the microemulsion polymerization of styrene- prepared by copolymerization monomer as the wall material, n-hexadecane, n-octadecane and butyl stearate as phase change material microcapsule core material, with the aid of scanning electron microscope(SEM), differential scanning calorimetry(DSC), thermogravimetric analyzer(DTA, TG), laser particle size instrument testing instruments, such as the effects of emulsifier, initiator, monomer, monomer and the ratio of core material on the structure and properties of phase change materials of the preparation of microcapsule, the influence of microcapsule of phase change material, surface morphology, particle size and distribution of the thermal properties have been characterized and analyzed. The preparation of microcapsule trial in the baptism of cotton fabric finishing, and the finishing of cotton fabrics after phase transformation temperature adjustment function is evaluated.The experimental results show that:(1) the styrene-methyl acrylic polymer P(St- co-MAA) as wall material,are cetane and butyl stearate two differentcateg ories of phase change materials with phase change materials can be successfull y prepared microcapsules. Optimization of process conditions for: the mass frac tion of 1.7% potassium persulfate as an initiator, 2.2% Tween 20 as emulsifier,core n-hexadecane:butyl stearate=3:2,shell material monomer benzene ethylene:m ethacrylic acid=10: 3, the core material:shell material = 0.7: 1, the speed is 350 r / min, emulsifying time was 40 min, the prepared dual core material of micr o-encapsulated phase change material by using emulsion polymerization geted t he best quality. Its surface morphology was stable, smooth and full, particle siz e was uniform, the average particle size was 7.172μm, the phase transition tem perature were 20.43℃, 17.23℃, latent heat were 55.09J/g,-54.06J/g. It was in a yield of 97.24%, 86.05% was coated.(2) The styrene-methyl acrylic polymer P(St-co-MAA) as wall material, Cetane and octadecane as core material with phase change materials can be successfully prepared microcapsules. Optimizati on of process conditions for: use the mass fraction of 2.4% Tween 20 as emul sifier, the mass fraction of 1.9% potassium persulfate as the initiator, the speed is 350 r / min, the core material of n-hexadecane and n-octadecane ratio was 1:4. The resulting phase change material microcapsules is ideal. The average p article size were 9.231μm, the melting temperature was 26.63℃, the freezing t emperature was 23.88℃, the Hm was 67.60 J / g, Hc was-67.95J/g, the embed ding rate was about 82.97%.(3)the application of the phase change material mi crocapsule of homemade finishing of cotton pad method, when the dosage of c ement is 50%, rolling rate was 90%, the fabric has good air permeability and good soaping fastness, melting temperature of 23.31℃, the phase transition ent halpy value of 16.92J/g, heat enthalpy relatively ideal. |
PDF Full Text Request