Synthesis And Property Of Polyurethane Microcapsules With Thermally Sensitive And Controlly Released Functions

Microencapsulation is defined as a technique for packaging sensitive ingredients in a sealed capsule. Due to flavors composed of aroma compounds are inevitably volatile and sensitive to oxidization or hydrolization, their applications to textiles need to be controlly released. Phase change paraffin is also widely utilized to textiles for the comfortable cloths. Therefore, both controlled release of flavors and phase change are two important functions of the microcapsules applied to textiles. Intelligent polyurethane microcapsules with phase change and controlly released functions were investigated in this work.There are three steps in preparing microcapsules with thermally sensitive and controlled release of flavors:(1) Trimethylol undecane has been synthesized from lauric aldehyde and formaldehyde using sodium hydroxide as catalyst. The structure of synthesized product, trimethylolundecane, has been characterized with13C and1H Nuclear Magnetic Resonance (NMR). The effects of reactant ratio, catalyst amount, reaction time and reaction temperature on the yield of trimethylolundecane have been investigated.(2) Texamethylene diisocyanate-trimethylolundecane oligomers were prepared using hexamethylene diisocyanate (HDI) and synthesized trimethylolundecane. The oligomers were characterized by FTIR spectroscopy and NMR.(3) Encapsulation of flavor oil and paraffin by interfacial polycondensation using gelatin was investigated. The configuration of the microcapsule was characterized by Scanning Electron Microscopoe (SEM), and its calorific property was characterized by Differential Scanning Calorimeter (DSC).Microcapsules in textiles have many potential applications including insect repellents, dyes, vitamins, antimicrobials, phase change materials, and specific medical applications such as antibiotics, hormones, and other drugs. The desire for a healthier and more productive lifestyle will continue to generate a market for textiles that promote "well-being". Textiles that "interact" with the consumer, reducing stress, promoting comfort, and relaxation are possible through active delivery from microcapsules.