切片石蜡乳液的制备

石蜡一直存在难乳化、乳液稳定性差等问题。研究了以切片石蜡为原料,采用种子乳液聚合法,选择复配型乳化剂;讨论了乳化剂用量,乳化时间,乳化温度以及搅拌速度等因素对石蜡乳液稳定性和分散性的影响。结果表明:在乳化剂用量为乳液总量的10%,乳化时间为70 m in,乳化温度控制在(85±5)℃,搅拌速度为1500 r/m in的反应条件下,可制备出稳定的切片石蜡乳液。     

硅丙乳液防水剂的研制

以甲基硅醇盐、丙烯酸酯为原料,OP-10、十二烷基苯磺酸钠(SDBS)为乳化剂,通过乳液聚合反应,制成硅丙乳液防水剂。考察了聚合反应温度、乳化剂种类及用量、原料配比、搅拌速度对乳液稳定性的影响。结果表明,合成硅丙乳液的最佳工艺条件为:30g水、58g甲基硅酸钠、12g丙烯酸酯、2gOP-101、0.3gSDBS,分散和乳化阶段的搅拌速度为400r/min、合成阶段的搅拌速度控制在200r/min,反应温度65℃,反应时间2h。采用本工艺合成的硅丙乳液稳定性好,内掺、外涂防水效果明显。     

水性酚醛环氧树脂乳液的制备

采用F-11型乳化剂和相反转技术制备水性酚醛环氧树脂乳液,研究了乳化剂的用量、乳化温度、乳化时间和搅拌速率对所得水性酚醛环氧树脂乳液稳定性的影响,得出了较佳的乳化工艺条件:乳化剂浓度为9.0%～10.0%、乳化温度为70℃、搅拌速度为800～1000 r/min、乳化时间为40～50 min并采用激光粒度衍射分析仪表征了所制备的水性酚醛型环氧树脂乳液的粒径在500～800 nm。     

操作条件对柴油微乳液制备及稳定性的影响

利用微乳化剂Span 80(失水山梨醇单油酸酯)、D 08/1021(双烷基氯化铵),助乳化剂正戊醇,自来水制备出了柴油微乳液;进一步探讨了温度、加料方式、搅拌方式等对制备微乳液的影响.结论为温度在30-35℃时制备的微乳液澄清较快,而加料方式以及加料过程中的搅拌对微乳液的制备无影响.对所制备的微乳液样品进行稳定性验证:先混配制得微乳化剂,再将柴油和微乳化剂混合均匀,搅拌一段时间后加入水,再搅拌一段时间后加助乳化剂正戊醇,操作温度控制在30℃,由此制得的柴油微乳液澄清较快,且稳定性高.     

非离子型蜡乳液的制备工艺

选用复配Ⅰ型乳化剂作为石蜡的乳化剂,考察乳化剂用量、乳化温度、乳化时间、搅拌速度等因素对蜡乳液性能的影响。通过实验确定了制备非离子型蜡乳液的最佳工艺条件:复配Ⅰ型乳化剂用量为蜡乳液用量的10%,乳化温度为85℃,乳化时间为45min,搅拌速度为1000r/min。在此条件下,可制备得到稳定的平均粒径为0.381um,分散度为0.373的石蜡乳液。     

稳定石蜡乳液的制备

研究石蜡乳液的制备,以工业石蜡为主要原料,采用剂在油中法,考察了乳化剂的选择以及其复配比例和乳化条件（乳化温度、搅拌速度）对石蜡乳液稳定性的影响。     

反应釜改造对丙烯酸乳液性能影响的研究

文章分析了丙烯酸高分子乳液聚合反应的工艺特点,研究了反应釜不同的加液过程、搅拌过程和传质传热过程对乳液性能的影响,并改造了聚合设备的加液装置、搅拌装置和热交换型式,提高了公司高分子乳液的使用性能和应用效果。     

相反转法制备醇酸树脂乳液

采用相反转法制备水性醇酸树脂乳液,探究搅拌速度、加水速度、乳化温度等工艺条件对乳液制备产生的影响。结果表明：乳化剂加量 5%,200^#溶剂油加量为 3%,搅拌速度 4 000~ 6 000 r/min,加水速度 90~120 mL/h,乳化温度 50~60 ℃,KOH加量为 0.5%时所制备的乳液粒径 D₉₀≤ 307 nm,乳液稳定性,涂膜各项性能均达到相关国标要求。     

固体切片石蜡乳液制备新工艺

以固体切片石蜡为原料,采用种子乳液聚合法,利用HLB值理论,以复配型乳化剂制得O/D型加水转化为O/W型石蜡乳液,可降低固体石蜡用量,增加乳化水用量,减少生产成本。考察了乳化剂用量、乳化时间、乳化温度以及搅拌速度等因素对石蜡乳液稳定性和分散性的影响。正交实验结果表明:在乳化剂用量为乳液总量的8.6%,乳化时间90 min,乳化温度控制在80±5℃,搅拌速度1500 r/min的反应条件下,可制备出稳定的固体切片石蜡乳液。     

四元纯丙无皂共聚物乳液的研制

采用反应型乳化剂，制备了四元纯丙共聚物乳液。讨论了该乳液的聚合工艺、引发剂、聚合温度、搅拌速率对乳液性能的影响。比较了该乳液和常规乳液的性能指标，试验结果表明，与常规乳液相比，该无皂乳液的耐水性和稳定性明显提高。     

工业聚合反应装置：Ⅳ.乳液聚合反应器（下）

讨论了釜式乳液聚合反应器搅拌桨的选择原则及其搅拌特性和乳液聚合反应器的放大准则，聚合过程的控制及其优化。     

乳液聚合过程中搅拌对产品质量的影响

综述了乳液聚合过程中搅拌强度对乳胶粒径、聚合反应速率、乳液稳定性的影响及搅拌器形式的影响。指出应根据不同阶段采用最佳的搅拌控制方法。     

Nanosized polypyrrole affected by surfactant agitation for emulsion polymerization

Nanosized conductive polypyrrole (PPy) powders were prepared using emulsion polymerization with aid of high speed agitation. Different agitation speeds from 650 to 24,000 rpm were used with different anionic, cationic, and non-ionic surfactants. Then, the effects of the agitation speed and surfactant species were examined in terms of their physical and electrical properties of conductivity and powder size. Prepared PPy nanopowders exhibited high conductivity values of 10 S/cm regions, when sodium dodecylbenzenesulfonate (SDBS) and sodium dodecylsulfate (SDS) were used. The powder dispersion of the resultant PPy was also observed to be dependent on the agitation speed and surfactant type. The morphology shown by SEM and TEM revealed that the anionic SDBS surfactant could effectively disperse into nanosized aggregates of the PPy. The results showed that the combination of the anionic surfactants and high agitation in the emulsion polymerization could produce nanosized PPy powders with higher conductivity.     

低皂高稳丙烯酸酯单体细乳液的制备 Ⅰ.乳液稳定性影响因素

研究在低乳化剂浓度 (约 0 .2 %,基于水 )条件下 ,丙烯酸酯细乳液稳定性的影响规律及高稳定细乳液的制备方法。结果表明乳化剂的优劣顺序为十六烷基硫酸钠 >十六烷基三甲基溴化铵 >十二烷基硫酸钠 >十二烷基聚十五氧乙烯醚 ;与乳化剂碳链长度相近的助乳化剂优于其他助乳化剂 ;当用搅拌乳化时脂肪醇优于同碳链的烃 ,当用超声波乳化时 ,结果相反 ;加分散相前的分散强度愈高 ,时间愈长 ,乳液稳定性愈高 ;加分散相后的乳化强度一定时 ,乳液稳定性有一最大值 ,达到最大稳定性的时间有一最佳值 ,乳化强度愈高 ,这一最大值愈大 ,达到最大值所需时间愈短 ;分散相水溶性愈大的乳液稳定性愈差 ;乳化与贮存温度也对乳液稳定性有很大影响。     

The effect of flow regime on the continuous emulsion polymerization of styrene in a tubular reactor

Five isothermal emulsion polymerizations of styrene in a tubular reactor were studied experimentally using an emulsifier concentration in the vicinity of the critical micelle concentration (CMC). The flow regime was characterized by an emulsion Reynolds Number (N_Re)_e calculated using the emulsion properties prior to any appreciable reaction. It was found that the rate of polymerization was a maximum at the laminar-turbulent transition based on (N_Re)_e. This behavior is similar to emulsion polymerizations carried out in batch reactors where a maximum rate of polymerization has been observed when the agitation level (agitator rotation rate) is varied. The controlling mechanisms appear to be similar at high agitation levels but differ when the emulsion is weakly agitated.     

粒径分布对嵌段聚醚氨基硅乳液性能的影响

通过机械搅拌、均质化等制备了一系列pH=5.9的嵌段聚醚氨基硅(BPEAS)乳液,用激光粒度分布仪和透射电子显微镜对乳液粒径和结构进行了表征,并探讨了不同粒径分布的乳液对整理织物性能的影响,确定了合适的粒径范围。结果表明,中位径(D50)分布在32.67～52.48 nm,粒径在58.77～98.82 nm时的累积分布达到90%以上的乳液具有较好的稳定性;经整理后的织物白度基本不变,弯曲刚度明显下降,亲水性增强,综合应用性能优异。     

氟硅改性丙烯酸酯乳液的研制

以十二烷基硫酸钠、OP-10和FC-4为复合乳化剂,合成了氟硅改性丙烯酸酯乳液,研究了引发方式、反应温度、反应时间和搅拌速度对反应过程的影响,该改性树脂能大大提高水性外墙涂料的耐候性、耐污性。     

Effect of mixing protocol on formation of fine emulsions

Emulsions are usually stabilised with a mixture of surfactants with different hydrophilicity. The initial partitioning of surfactants between the dispersed phase and continuous phase, and how these phases are brought into contact, can significantly affect the emulsification processes. Dynamic-phase behaviour maps were prepared to allow for a systematic investigation of the effects of emulsification routes on emulsion properties. Six semibatch modes of additions with constant surfactant concentration across the routes were selected. For a target cyclohexane-in-water emulsion using a pair of polyoxyethylene nonylphenyl ether surfactants with a specified HLB and water volume fraction, fine droplets could form only if water dissolving the water-soluble surfactant was added to the oil dissolving the oil-soluble surfactant. This route allowed the transitional inversion to occur and as a result fine droplets were formed due to an ultra-low interfacial tension. The addition of water dissolving the water-soluble surfactant to oil dissolving the oil-soluble surfactant, direct emulsification method, produced by far large droplets because of a rather high interfacial tension. In a series of experiment, the semibatch direct and phase-inversion emulsification method, were assimilated in situ. The impeller location was used as a variable that controls which phase is added as the dispersed phase. The location of impeller in relation to the interface did not affect the emulsion drop size at a high agitation rate, but it did at a low agitation rate. Under low agitation speed and when the impeller was placed in the oil phase, the oil layer progressively, but slowly, dragged the water phase and eventually inverted to an oil-in-water emulsion, indicating that transitional-phase inversion has locally occurred in the oil layer. At a high agitation speed the mechanical energy provided by the impeller homogenised the emulsion instantaneously and did not allow the optimum formulation and the associated ultra-low interfacial tension to be reached regardless of location of the impeller. A high impeller speed increased drop size by transforming the transition inversion mechanism to a catastrophic mechanism under which the size of drops is mainly determined by the mechanical energy provided. This paper aims to show how some of the complexities involved in emulsification processes can be explained by consulting with dynamic-phase maps.     

Preparation of epoxy acrylate emulsion using mixed surfactants and its polymerization

Summary A series of epoxy acrylate emulsions were prepared with several surfactants ranging from HLB 12 to 14 at 40°C. For epoxy acrylate emulsion, additives and conditions were established among factors: HLB value of emulsion, agitation speed, water dropping speed, and dropping amount of the deionized water. For emulsion polymereization with water soluble initiator KPS, emulsion was broken during polymerization, because interfacial complex formed by association of surfactant with co-surfactants stabilizing emulsion was weakened by interpenetration of radicals formed at aqueous. Accordingly, the polymerization of epoxy acrylate emulsion was carried out by using oil soluble initiator, AIBN, and the conversion changes with initiator concentration and HLB values were investigated.