亚甲基二甲胺盐酸盐淀粉醚的制备及其吸湿保湿性能研究

以淀粉为母体,羟甲基二甲胺盐酸盐(HMMAHC)为醚化剂,通过干法工艺合成出不同取代度(DS)的叔胺型阳离子淀粉——亚甲基二甲胺盐酸盐淀粉醚(SMMAHC),并考察了其吸湿、保湿性能。结果表明,该阳离子淀粉的吸湿、保湿性能均随着阳离子基团取代度的增加而增强。在相对湿度(RH)为81%的条件下,当阳离子取代度分别为0.36和0.70时,其吸湿性分别与透明质酸(HA)和丙三醇相当。而取代度为0.70的SMMAHC保湿性在相对湿度43%和15%下均与透明质酸相当,优于丙三醇。探讨了SMMAHC吸湿动力学,可应用伪二级吸附动力学模拟方程很好地描述吸湿性能,相关系数达到0.999以上。

Preparation and Moisture-adsorption and Retention Ability Investigation of Starch-methylene Dimethylamine Hydrochloride

A tertiary amine type cationic starch——starch-methylene dimethylamine hydrochloride(SMMAHC)with different degrees of substitution(DS)was prepared by the reaction of corn starch with cationic reagent hydroxymethyl dimethylamine hydrochloride(HMMAHC)using the dry process.The moisture-adsorption and retention ability was investigated.The results showed that the moisture-adsorption and retention ability of cationic starch increased with DS of cationic groups.Under the condition of relative humidity(RH)81%,when the DS of cationic starches were 0.36 and 0.70,their moisture-adsorption abilities were equal to those of hyaluronic acid(HA)and glycerin respectively.At RH 43% and 15%,the moisture-retention ability of SMMAHC with DS of 0.70 was equal to those of hyaluronic acid,superior than glycerin.Moisture absorption kinetics of SMMAHC was preliminary studied,the pseudo-second order model of adsorption kinetic equation can characterize the adsorption process very well and the relation coefficients are all higher than 0.999.