The Synthesis And Surface Modification Of The Thermal Expandable Microspheres

The high-temperature expandable microspheres containing methacrylic acid can be successfully preparation by suspension polymerization. In the case of that the low-temperature expandable microspheres can’t meet the needs, methacrylic acid can greatly improve the foaming properties of the microspheres. By a comparative analysis of the morphology of the micro structure of the expanded microspheres, the main factors to affect the multicore morphology of the microspheres have be found, and the formulation have be improved to avoid the emergence of multi-core morphology. Through a series of analytical testing, such as thermal mechanical analysis, thermal gravimetric analysis, and particle size analysis, foaming properties of the microspheres were compared and analyzed.And the main factors that affect the foaming properties of the microspheres have been found.After the foam microsphere was analyzed and researched, it is found that the hydrophilic and lipophilic of the microsphere shell’s surface often do not meet the requirements. In order to improve the use characteristic of the microspheres under various conditions, the surface of the microspheres should be prepared for surface graft modification. By two ways of initiator infiltration attachment and ozone treatment to deal with microspheres, the treated microspheres grafted with hydrophilic or hydrophobic monomer. Through a series of analytical testing with before and after the microspheres graft, such as acid-base titration. hot stage microscopy, thermal mechanical analysis, thermal gravimetric analysis, particle size analysis and determination of the water contact angle analysis and so on, various types of data, including percent grafting expansion ratio and effect, weight loss rate, particle size distribution and water contact angle. By analyzing and collating of these data, the feasibility of the grafting reaction of the microspheres are sured and factors of affecting the percent grafting are obtained.