电解质对淀粉与PVA混合浆相分离行为的影响

以初显分离时间和沉降率为量化指标，定量研究了硫酸钠、氯化钠和磷酸二氢钠3种电解质对淀粉与PVA混合浆相分离行为的影响。结果表明，这3种电解质的存在都会使混合浆的相分离速度明显增大，但对相分离程度影响不大。此外，本文还研究了电解质存在下淀粉品种、聚乙烯醇分子量和醇解度、以及混合浆液中淀粉含量对混合浆相分离行为的影响。

Effects of Some Electrolytes on the Phase-separation Behaviors of Polyvinyl Alcohol/Starch Pastes

The effects of some electrolytes on the phase-separation behaviors of polyvinyl alcohol-starch pastes were quantitatively evaluated in terms of initial demixing time and subsidence ratio. The electrolytes such as sodium sulfate, sodium chloride, and sodium dihydrogen phosphate were individually mixed with the blended pastes. The starches considered included native cornstarch, cassava starch, and wheat starch whereas the polyvinyl alcohol involved both completely and partially alcoholized ones. It was found that the electrolytes accelerated the separation rates, and the acceleration of electrolytes to the separation rates follows the order: vNaH2PO4>vNAa2SO4>vNaCl. But the electrolytes did not show evident effect on the separation extent. Furthermore, the influences of the electrolyte content, starch resource, molecular structure of polyvinyl alcohol, and-mixed ratio of starch to polyvinyl alcohol upon the separation behaviors were also investigated.