SMA的合成及其对香精的分散和微胶囊制备的影响

使用溶液聚合法合成苯乙烯-马来酸酐共聚物（SMA）,利用盐化的苯乙烯-马来酸钠盐作为保护胶体分散香精,采用原位聚合法制备三聚氰胺甲醛树脂香精油微胶囊。探究了不同分子量的SMA钠盐对香精的分散作用和对香精油微胶囊制备的影响,并与进口SMA 520对香精的分散作用和微胶囊制备效果进行了对比。实验发现,随着SMA分子量减小,香精油趋向于以较小粒径的液滴分散在连续相中,粒径分布逐渐变窄,香精油滴的分散稳定性提高。当使用的SMA钠盐溶液（质量分数10%）黏度≥145mPa·s时,可制备出粒径为5～20μm,形态为球形、表面有少许凹陷、壳层厚度较为均匀的微胶囊。当使用的SMA钠盐溶液（质量分数10%）的黏度≤67mPa·s时,只能形成极少数的球形微胶囊。作为保护胶体制备香精油微胶囊,进口SMA 520与实验室制备的黏度为314mPa·s的SMA钠盐溶液（质量分数10%）具备相似的效果。

Synthesis of styrene-maleic anhydride copolymer (SMA) and its effect on the dispersion of perfume oil and the preparation of microcapsules

Styrene-maleic anhydride copolymer(SMA) was synthesized by solution polymerization, and then the salted styrene-maleate was used as a protective colloid to prepare perfume oil filled melamine formaldehyde microcapsules by in-situ polymerization. The effects of SMA sodium salts with different molecular weights on the dispersion of perfume oil and the preparation of perfume oil microcapsules were investigated. It was found that by decreasing the molecular weight of SMA, the particle size and the particle size distribution of perfume oil droplets decreased, while the dispersion stability of the perfume oil droplets increased. When the viscosity of the SMA sodium salt solution(10% mass fraction) was ≥145 mPa·s, the particle size of the prepared microcapsules was in the range of 5—20μm, with spherical shapes, smooth surfaces and the thickness of the shell is relatively uniform. When the viscosity of the SMA sodium salt solution (10% mass fraction) was ≤67mPa·s, only few microcapsules can be prepared. The performance of the imported SMA 520 was similar to the self-prepared SMA sodium salt solution (10% mass fraction) having a viscosity of 314mPa·s.