天然杜仲胶乳的制备及表征

采用溶液乳化法制备了杜仲胶乳，考察了乳化配方及乳化工艺对乳化效果的影响，确定了如下制备条件：以杜仲胶的环己烷溶液（杜仲胶的质量分数为6%）为油相胶液，采用1% Brij-52、0.5% Tween-20、0.5%十二烷基苯磺酸钠的三相复配乳化剂体系，油水体积比为1：1.5，乳化方式为高速搅拌（8 000 r/min，10 min），除溶剂方式为旋转蒸发（-0.09 MPa，40℃），浓缩方式为离心浓缩（10 000 r/min，10 min）。在优化条件下制备的杜仲胶乳的固含量可达54%，粒径约为330 nm，Zeta电位的绝对值可达57 mV。采用X射线衍射法（XRD）、差示扫描量热法（DSC）、傅里叶变换红外光谱法（FT-IR）、扫描电子显微镜（SEM）和偏光显微镜（POM）对制备的杜仲胶乳进行了表征，结果表明：乳化没有破坏杜仲胶的结晶性能，杜仲胶乳中仍存在大量的微结晶，杜仲胶乳的晶型中以β晶型为主。

Preparation and characterization of natural Eucommia ulmoides latex

Eucommia ulmoides latex was prepared by a solution emulsification method. The influence of the emulsification formulation and processing on the emulsification effect was investigated. The following optimum preparation conditions were identified:a cyclohexane solution of Eucommia ulmoides gum (with a mass fraction of Eucommia ulmoides gum of 6%) was used as the oil phase, with a three-phase compound emulsifier system of 1% Brij-52, 0.5% Tween-20 and 0.5% sodium dodecyl benzene sulfonate, a volume ratio of oil to water of 1:1.5, using high-speed stirring (8 000 r/min, 10 min) as the emulsification method, with solvent removal by rotary evaporation (-0.09 MPa, 40℃), and concentration by centrifugation (10 000 r/min, 10 min). The solid content of the Eucommia ulmoides latex prepared under these optimized conditions reached 54%, the particle size was about 330 nm, and the absolute value of the Zeta potential reached 57 mV. The Eucommia ulmoides latex was characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and polarized light microscopy (POM). The results showed that emulsification did not destroy the crystalline properties of Eucommia ulmoides gum, there were still a large number of microcrystals in the Eucommia ulmoides latex, and that the crystal form of the Eucommia ulmoides latex was dominated by β crystals.