几种极性增塑剂对淀粉/PVA混合浆相分离速度的影响

以初显分离时间为量化指标，选取丙三醇、尿素、1,2-丙二醇及乙二醇四种淀粉和PVA的常用增塑剂，定量研究了这些极性化合物对淀粉与PVA-1799及PVA-1788混合浆液相分离速度的影响.结果发现这4种极性化合物都能在一定程度上降低淀粉与PVA-1799混合浆液的相分离速度，尿素还具有提高淀粉与PVA-1788混合浆液稳定性的功能.此外，本文还研究了丙三醇和尿素的用量、淀粉与PVA的混合比例对混合浆液相分离速度的影响.

Effect of Some Polar Plasticizers on the Phase-separation Rates of Polyvinyl Alcohol/Starch Pastes

The influences of some polar plasticizers of starches and/or polyvinyl alcohol (PVA) upon the phase-separation rates of the blended starch/PVA pastes had been studied. The polar plasticizers such as glycerin, urea, 1,2-propanediol and ethylene glycol were individually mixed with the blended pastes. The separation rates were quantitatively evaluated by the initial demixing time of the blended pastes. It was found that all the polar substances studied here could reduce the separation rate of PVA-1799/native cornstarch pastes, whereas the rate of PVA-1788/native cornstarch paste could be only reduced by urea. Moreover, the influences of the amounts of glycerin and urea, and component content upon the separation rates were also investigated.