Influence of different suspension stabilizers on the preparation of Rubitherm RT31 microcapsules

Polystyrene microcapsules containing Rubitherm® RT31 were prepared by suspension-like polymerization method using different suspension stabilizers. These microcapsules could be applied to the textiles in a variety of processes to improve thermal comfort of end-use products. The effects of polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), arabic gum and gelatin as suspension stabilizers were investigated regarding thermal properties, particle size distributions, morphologies using differential scanning calorimetry, scanning electron microscopy and laser light scattering analyses.The type of suspension stabilizer had a significant effect on the particle size distribution and the morphology of the synthesized microcapsules. Spherical and regular microcapsules with smooth surface were obtained using PVP and gelatin as suspension stabilizers. However, with arabic gum and PVA irregular particles with rough surface were produced due to the interfacial tension between the polymer and the aqueous phase was close to that between PCM and polymer contacted the aqueous phase. On the other hand, the lowest average particle size in number and in volume was obtained for polyvinylpyrrolidone. The highest amount of Rubitherm® RT31 encapsulated was 67.9 wt.% for arabic gum.

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► Polystyrene microcapsules containing Rubitherm® RT31 were successfully prepared.
► Microcapsules with 75.7 J/g, a melting temperature of 31.56 °C and 4.01 μm were obtained.
► Arabic gum and PVA produce irregular particles with rough surface.
► The lowest average particle size was obtained for PVP.
► The highest amount of Rubitherm® RT31 encapsulated was 67.9 wt.% for arabic gum.