| 摘要 |
A ternary hydroxyethyl hydroxypropyl methylcellulose ether(I) was prepd. by reacting an alkali cellulose with chloromethane, ethylene oxide, and propylene oxide. (I) has a methoxy degree of substitution (MDS) of 0.9 - 2.1(pref. 1.25 - 2), a hydroxyethyl molar substitution(HEMS) of 0.2 - 0.5, and a hydroxypropyl molar substitution(KPMS) of 0.08 - 0.4(pref. 0.1 - 0.3). Pref. (I) has a cloud pt. of 70≦̸C or less and a return cloud pt. of no more than 10(pref. 5≦̸C lower). The viscosity of a 2 wt.% aq. soln. of (I) at 20≦̸C is 10 - 100,000 cps. (I) is used as a protective colloid in suspension polymerization processes, esp. of vinyl chloride.
|
