Abstract:
This research studied the preparation of polymethyl methacrylate nanocapsules encapsulated Rubitherms®27 (PMMA/RT27) by miniemulsion polymerization using poly (2- methacryloyloxy dodecyl dimethyl ammonium chloride-4-allyloxy-2-hydroxy benzophenone)-block-PMMA-iodide (P(QAC12-BP)-b-PMMA-I) as a polymerizable surfactant.
P(QAC12-BP)-b-PMMA-I was prepared by solution iodine transfer polymerization before being used as a surfactant in the fabrication of PMMA/RT27 nanocapsules. The influence of the MMA: RT27 ratio on the thermal properties and encapsulation efficiency of the encapsulated RT27 was studied. At 50: 50 %w/w, core-shell spherical nanocapsules of approximately 50 nm with high encapsulation efficiency (94%) were obtained. A high positive surface charge (≥ +70 mV) derived from the QAC12 unit dispersed on the nanocapsule surface provided nanocapules with high colloidal stability. The latent heat value of the encapsulated RT27 was high (191 J/g-RT27), which was close to that of the pristine RT27 (219 J/g). When heat increase and reduction was tested, the latent heat of melting and crystallization of the encapsulated RT27 was quite constant throughout 100 heating/cooling cycles. This indicated their thermal stability. Because of the presence of the BP unit in the polymerizable surfactant located on nanocapsules surfaces, the obtained nanocapsules were tightly coated on cotton fabrics by UV irradiation, giving them greater washing durability than using an external binder. The coated fabrics exhibited effective antimicrobial performance against S. epidermidis and C. glutamigum due to the presence of the QAC12 unit.
In conclusion, PMMA/RT27 nanocapsules were successfully produced by miniemulsion polymerization using P(QAC12-BP)-b-PMMA-I as a polymerizable surfactant. The fabricated nanocapsules with effective thermoregulating and antimicrobial properties are suitable for textile application.