丁基橡胶胶乳制备工艺的优化

以丁基橡胶（IIR）为原料,采用“溶解-乳化”法制备了稳定性较好的IIR胶乳,考察了乳化剂种类、乳化剂组成、pH值、油水质量比、浓缩工艺等对乳化效果和IIR胶乳产率的影响。结果表明,优化的IIR胶乳制备的乳化剂配方及制备工艺如下:乳化剂为油酸钾和Triton X-100,二者质量比为4/1;当体系pH值为10,油水质量比为4/5时,得到的IIR乳液稳定性最佳,胶乳产率最高;采用膏化工艺进行胶乳浓缩,以藻酸钠为膏化剂,占胶乳中橡胶质量分数为0.6%时浓缩效果最好;并采用离心分离工艺缩短浓缩时间,当转速为1 500 r/min,离心时间为20 min时,可获得总固物质量分数约为55%的IIR胶乳,胶乳产率达90%以上。     

Influence of lipase and/or emulsifier addition on the ileal and faecal nutrient digestibility in growing pigs fed diets containing 4% animal fat

Information on the addition of lipase and/or emulsifiers to less digestible or saturated fat sources, such as tallow or other animal fats, used in swine feeding is very limited. Therefore, in a 4 × 4 Latin square design, the effects of adding lipase (0.05% L5, microbial source) and/or an emulsifier (0.3% Lysoforte) on the apparent ileal (AID) and faecal (AFD) digestibility of the main nutrients and fatty acids in particular were studied with four ileal‐cannulated growing pigs (female, initial live weight 20 kg) fed diets containing barley/soybean meal supplemented with 4% animal fat. The fat source contained 35% saturated (S) and 65% unsaturated (U) fatty acids. All diets were free of antibacterial substances (antibiotics, copper sulphate or zinc oxide beyond requirements), in order to avoid interactions between the parameters studied and the gut flora. Lipase addition did not affect the AID or AFD of fat. However, the digestibility of minor fatty acids (C6:0, C14:0) was significantly improved by lipase at both ileal and faecal level. On the other hand, lipase supplementation (P < 0.05) improved the AID of dry matter (DM) and energy as well as the AFD of DM, organic matter (OM), crude protein (CP), ash and energy. Addition of an emulsifier did not have any significant influence on the AID or AFD of fat, while the AID values of DM, OM, CP and energy as well as the AFD values of DM, OM, CP and ash were significantly (P < 0.05) improved. Adding lipase in combination with an emulsifier to the diets decreased (P < 0.05) the AID and AFD of fat, with minor effects on the AID and AFD of the non‐fat components of the diet. The lack of improvement in the digestion of fat by exogenous lipase and/or emulsifier may be related to the rather high U/S ratio (0.65:0.35) of the animal fat source used and to the mode of incorporation of the emulsifier (no pre‐dispersion in the fat source). Furthermore, during the trial the diets, stored at room temperature, showed a steady increase in their content of free fatty acids (to more than 700 g kg^?1 fat), due to endogenous lipase activity, leaving less room for upgrading the digestion of animal fat by exogenous lipase and/or emulsifier. Copyright © 2004 Society of Chemical Industry     

大米饮料的稳定性研究

研究了11种不同稳定剂和乳化剂对大米饮料稳定性的影响,从中筛选出4种效果较好的稳定剂和乳化剂进行正交试验,以期提高大米饮料的稳定性。结果表明,添加0.60%果胶、0.165%黄原胶和0.60%单甘酯时,大米饮料的稳定性最好,沉淀率仅为0.87%,常温下放置3周没有出现分层现象。此外,黄原胶对大米饮料的稳定性已达到极显著水平(P0.01),果胶为显著水平(P0.05);乳化剂单甘酯和司盘40均为不显著(P0.05),但单甘酯对大米饮料的稳定性影响远大于司盘40。     

不同乳化剂对咖啡乳饮料稳定性的影响

通过对咖啡乳样品粒径分布、Turbiscan稳定性分析,研究乳化剂分子蒸馏单甘酯(GSM-HP-C)、蔗糖酯肪酸酯(SM-P-1570)、双乙酰酒石酸甘油酯(DATEM)和琥珀酸单甘油酯(SMG)在相同条件下对咖啡乳饮料稳定性的影响。结果表明,各单体乳化剂的添加量分别为:分子蒸馏单甘脂1.1 g/kg、蔗糖酯肪酸酯1.1 g/kg、双乙酰酒石酸甘油酯0.7 g/kg、琥珀酸单甘油酯0.7 g/kg时对咖啡乳饮料的稳定体系效果相对较好,4种单体中蔗糖脂肪酸酯的稳定效果最优。     

再生纸浆用阴离子分散松香施胶剂的制备

对天然松香进行强化和酯化改性,确定了再生纸浆用的松香的最佳加成量和酯化度。以常压逆转乳化法制备了阴离子分散松香胶,对乳化剂的选择和配比、用量及转相高速搅拌时间进行了研究,测定了松香胶的乳液性质和施胶效果。     

乳化剂的HLB值对搅打稀奶油搅打性能的机理研究

重点研究了乳化剂的HLB值对搅打稀奶油的脂肪部分附聚率与搅打性能之间的关系．结果表明：高HLB值乳化剂在促进脂肪球的部分附聚的能力比低HLB值乳化剂强．HLB值低于6时，则部分附聚速度缓慢且部分附聚率低于50％，形成的泡沫结构稳定性差；乳化剂的HLB值在6～8之间，部分附聚速度适中，能够获得60％左右的脂肪部分附聚率和形成较理想的泡沫结构；HLB值大于9时，部分附聚速度过快且部分附聚率高于80％，形成的泡沫结构粗糙且稳定性差．     

环氧树脂乳液的稳定性问题

介绍了环氧乳液的制备方法、存在的问题及原因，着重从乳化剂的选择、工艺条件的优化、外加添加剂及贮存温度等方面介绍了提高环氧乳液稳定性的方法。     

自然乳化的理论及其应用

介绍了自然乳化的三种不同理论及其在毛纺工业中的应用。     

水性黑推光漆的制备与性能研究

本文以聚乙烯醇(PVA-124)作为乳化剂制备水性黑推光漆(WBPL),探讨黑料(氢氧化亚铁胶体)含量、乳化温度、乳化剂用量等因素对WBPL稳定性和流变性能的影响,并用透射电镜观察其微观结构。实验结果表明:当黑料(氢氧化亚铁)含量为3.0%,乳化温度为30℃,乳化剂(聚乙烯醇PVA-124)用量为4.7%时,所制备出的WBPL乳液稳定性最好;WBPL是假塑性流体,均有剪切变稀的特性,其流变曲线能与Herschel-Bu lkley和Casson模型良好拟合。