【作者】 郝家宝；

【导师】 夏茹；

【作者基本信息】 安徽大学 ， 高分子化学与物理， 2013， 硕士

【摘要】 在人造板行业,高固含量、稳定性好的石蜡乳液防水剂具有生产效率高、运输成本低、干燥快、能耗低等优点,目前已成为该领域的研究热点,越来越受到市场的重视。但高固含量石蜡乳液存在石蜡不易乳化、乳液不稳定且粘度大等缺点。本论文以高固含量的非离子型和阴离子型石蜡乳液为研究对象,探讨了石蜡乳液的稳定性、流变性及其影响因素,研究制备出高固含量的石蜡乳液。论文第二章研究采用转相乳化法制备高固含量的非离子型石蜡乳液。利用亲水亲油平衡(HLB)法选择乳化剂种类,同时从乳化剂的结构方面讨论了不同类型乳化剂对乳液性能的影响,结果表明以单硬脂酸甘油酯与聚氧乙烯醚100单硬脂酸酯复配成HLB值为13.0的复合乳化剂制得的乳液性能较好,复合乳化剂用量仅为5%；采用正交实验设计方法获得乳液的最佳制备工艺：乳化时间为20min、乳化温度为85℃、剪切速率为5000rad/min、分3次加入乳化水。研究得到的石蜡乳液固含量约为51.6%、乳液粒径分布范围0.3-5.0μm,涂-4杯法测得黏度为15s、离心稳定性为99.8%;利用Malvern旋转流变仪研究乳液的流变性能,稳态速率扫描结果表明非离子型石蜡乳液为非牛顿流体,具有剪切变稀的性质,显示出假塑性。随着乳液固含量增大,体系的非牛顿指数m逐渐变小,动态应变扫描结果表明,在剪切应变小于0.02%时,乳液以弹性为主,具有较好的稳定性；大于0.02%时,乳液则表现为黏性。论文第三章研究采用初生皂法制备高固含量的阴离子型石蜡乳液。以硬脂酸为乳化剂,氨水为皂化剂,研究了皂化率(n硬脂酸：n氨水)对乳液性能的影响,结果表明皂化率为1.2：1时制得的乳液综合性能较好,乳化剂用量为4.5%；利用电导率法研究了乳液电导率与相行为的关系,获得石蜡乳液的相转变规律；采用正交实验方法得到乳液的最佳制备工艺为乳化时间20min、乳化温度85℃、剪切速率8000rad/min、分3次加水。所得乳液的固含量为48.9%、乳液粒径分布3.5-11.0μm、涂-4杯法测得黏度为17s、离心稳定性为89.5%；研究表明当加入0.25wt%的聚乙烯醇1799与0.25wt%的硅酸镁锂作为稳定剂,乳液的离心稳定性提高至98.8%;研究了乳液制备过程中泡沫的消除方法,在出料前添加0.5wt%的改性聚硅氧烷乳液消泡剂能起到较好的消泡效果,同时冷却后采用真空脱泡,能完全除去乳液中的泡沫；研究表明阴离子型石蜡乳液为非牛顿流体,具有剪切变稀的性质,显示出假塑性。随着乳液固含量增大,非牛顿指数m逐渐变小,动态应变扫描结果表明,在剪切应变小于0.02%时,乳液以弹性为主,具有较好的稳定性；大于0.02%时,乳液则表现为黏性。论文第四章研究了低熔融粘度C-5石油树脂水基乳液的制备及性能。以56#半精炼石蜡为粘度调节剂,系统考察了非离子型复合乳化剂的HLB值和用量对C-5石油树脂乳液的稳定性、粒径分布、粘度和表面张力的影响。研究结果表明,添加30%的石蜡可以明显降低石油树脂的熔融粘度,使物料在较低温度下实现均匀混合；复合乳化剂的最佳HLB值为10.75；最佳用量为m乳化剂/m油相=16%。通过正交实验确定了优选乳化工艺条件为：乳化温度98℃、乳化时间20min、剪切速率5000r/min、乳化水占水相的比例为1/3。该条件下可制得固含量约为40.0%,稳定性好、粒径小、黏度低的O/W型C-5石油树脂乳液,该乳液也可作为人造板防水剂。更多还原

【Abstract】 Paraffin emulsion as a waterproof agent is generally used in the wood-based panel industry. Compared with solid paraffin, people do not need to melt or dissolve when use paraffin emulsion, and it has anti-acid-base and other excellent performance, besides, it has a safe, efficient and economical advantages. Two types of paraffin emulsion (Non-ionic paraffin emulsion and Anionic paraffin emulsion) were prepared in this thesis and the stability and rheological properties of different types of paraffin emulsion were researched, too.Non-ionic paraffin emulsion was prepared with Phase Inversion Emulsification (PIE) method in Chapter2. The types of emulsifier were selected with Hydrophilic-Lipophilic Balance (HLB) method. And the effect of different emulsifier types to emulsion performance from the structure of the emulsifier was discussed. The results show that, with the composite emulsifier consisting of glycerol monostearate and polyoxyethylene (100) stearate and the HLB value is13.0, the emulsion with better performance can be obtained. The emulsifier dosage was determined at5%. The orthogonal experiment results showed that optimum conditions were, emulsifying time20minutes, emulsifying temperature85℃, stirring rate5000rad/min and emulsifying water was added by three times. The paraffin emulsion was prepared under this condition, with solid content is51.6%, emulsion particle size distribution range is0.3-5.Oμm, viscosity is15s, centrifuged stability is99.8%. Malvern rheometer was used to study the rheological properties of the emulsion, the paraffin emulsion usually show a non-Newtonian fluid, specifically a pseudoplastic behavior, with the nature of shear-thinning, with the addition of the solids content of the emulsion, the non-Newtonian index m tends to gradually decreases. The results of dynamic strain sweep show that emulsion demonstrated resilience with the strain less than0.02%, and emulsion demonstrated viscous with the strain more than0.02%.Anionic paraffin emulsion was prepared with saponification method in Chapter 3. Selecting stearic acid as emulsifier, ammonia as saponifier, the saponification rate on the properties of emulsion was studied. The results show that, with the saponification rate1.2:1, the emulsion with better performance can be obtained, the emulsifier dosage was determined at4.5%. The relationships between the emulsion conductivity and the phase behaviors were studied with the conductivity method. The orthogonal experiment results showed that optimum conditions were, emulsifying time20minutes, emulsifying temperature85℃, stirring rate8000rad/min and emulsifying water was added by three times. The solid content of the paraffin emulsion is48.9%, and the distribution range of the emulsion particle size is3.5-11.Oμm, And the viscosity of the paraffin emulsion is17s with centrifuged stability is89.5%. The appropriate stabilizer was added to improve the stability of the emulsion, when PVA1799used in conjunction with lithium magnesium silicate, the centrifuged stability of the emulsion increased to98.8%, Foam has a significant negative impact on the performance of the emulsion, the methods for eliminating foam during emulsion preparation process was researched, add silicone defoamer with0.5%mass fraction before discharge the material can play a better anti-foaming effect, the foam can be completely removed from the emulsion after cooling using a vacuum degassing. Malvern rheometer was used to study the rheological properties of the emulsion, the paraffin emulsion usually show a non-Newtonian fluid, specifically a pseudoplastic behavior, with the nature of shear-thinning, with the addition of the solids content of the emulsion, the non-Newtonian index m tends to gradually decreases. The results of dynamic strain sweep show that emulsion demonstrated resilience with the strain less than0.02%, and emulsion demonstrated viscous with the strain more than0.02%.Preparation of petroleum resin emulsion and its performance were discussed in Chapter4. An O/W type C-5petroleum resin emulsion was prepared with paraffin wax as viscosity regulator and blend of nonionic emulsifier. Effect of HLB value and concentration of emulsifier on stability, droplet size, viscosity and surface tension of the petroleum resin emulsion were examined. The results showed that when the paraffin added with30%percentage composition, the C-5petroleum resin melt viscosity decreased obviously and the material in the low temperature mixing uniformly. The suitable HLB value is about10.75and emulsifier concentration is16%. The orthogonal experiment results showed that optimum conditions were, emulsifying temperature98℃, emulsifying time20minutes, stirring rate5000rpm and emulsifying water quantity1/3. The O/W type C-5petroleum resin emulsion which solid content is40.0%was prepared under this condition; it showed excellent stability, small droplet size and low viscosity.更多还原