聚丙烯酸酯乳液用有机硅消泡剂的制备及性能研究

先采用二甲基硅油、MQ硅树脂和二氧化硅制得硅膏，再与聚醚、聚醚改性硅油、乳化剂、水和增稠剂混合制得乳液型有机硅消泡剂。探讨了二氧化硅种类及其在硅膏中用量，硅膏用量，聚醚的种类、摩尔质量和用量对有机硅消泡剂消泡性能及抑泡性能的影响，还考察了聚醚改性硅油HLB值和用量、乳化剂种类和用量对有机硅消泡剂在聚丙烯酸酯乳液中稳定性的影响。结果表明，有机硅消泡剂的较佳制备条件为：二氧化硅选择R106,二氧化硅用量为5份，硅膏用量12份，聚醚选择平均摩尔质量3 000 g/mol的十八醇聚醚，聚醚用量5份，聚醚改性硅油HLB值为10,聚醚改性硅油用量8份，乳化剂选择异构十三醇聚氧乙烯醚，乳化剂用量3份。此时，制得的乳液型有机硅消泡剂的消泡时间为3.4 s,抑泡体积为400 mL,应用于聚丙烯酸酯乳液时的稳定性良好。     

乳液型有机硅消泡剂的研制

以甲基硅油、α,-二羟基聚二甲基硅氧烷(107硅橡胶)、气相法二氧化硅、聚醚硅油、Span-Twen复配乳化剂为主要原料,制得乳液型有机硅消泡剂。研究了各组分对消泡剂性能的影响。结果表明,当黏度为50、350、1 000 m Pa·s的甲基硅油与黏度为20 000 m Pa·s的107硅橡胶混合质量比为1∶3∶2∶2,二氧化硅相对于硅膏的质量分数为6%,消泡剂中聚醚硅油相对于硅膏的质量分数为6%,Span-Tween复配乳化剂相对于硅膏的质量分数为4%时,制备的消泡剂具有良好的消泡性、抑泡性、离心稳定性及水分散性。     

油用消泡剂的消泡抑泡性能评价

在自制的消泡剂性能评价装置上,研究了消泡剂在稠油模拟油中的使用量与消泡抑泡性能的关系。考察了硅油类、氟硅油类与硅醚类三种油用消泡剂的消泡抑泡性能与界面张力之间的关系。结果表明,硅油类、氟硅油类与硅醚类三种油用消泡剂合适的用量为35~45μg/g。在相同剂量下,硅醚型消泡剂的消泡抑泡性能最好。将消泡剂消泡性能与稠油模拟油界面张力进行关联发现,加入相同剂量的消泡剂后,硅醚消泡剂使稠油模拟油界面张力下降更显著。能大幅度降低稠油模拟油界面张力的消泡剂有更好的消泡抑泡性能。因此可以用降低界面张力能力的大小来衡量油用消泡剂的消泡抑泡性能。     

油用消泡剂的消泡抑泡性能评价

在自制的消泡剂性能评价装置上,研究了消泡剂在稠油模拟油中的使用量与消泡抑泡性能的关系。考察了硅油类、氟硅油类与硅醚类三种油用消泡剂的消泡抑泡性能与界面张力之间的关系。结果表明,硅油类、氟硅油类与硅醚类三种油用消泡剂合适的用量为35⁴5μg/g。在相同剂量下,硅醚型消泡剂的消泡抑泡性能最好。将消泡剂消泡性能与稠油模拟油界面张力进行关联发现,加入相同剂量的消泡剂后,硅醚消泡剂使稠油模拟油界面张力下降更显著。能大幅度降低稠油模拟油界面张力的消泡剂有更好的消泡抑泡性能。因此可以用降低界面张力能力的大小来衡量油用消泡剂的消泡抑泡性能。     

有机硅消泡剂的合成与应用

以烯丙醇聚氧乙烯聚氧丙烯醚(FB)、长链烷基酯与含氢硅油(PHMS)通过硅氢加成反应,合成了有机硅高聚物(改性硅油),用IR和1HNMR对其结构进行了表征。以改性硅油作为活性成分,制备了有机硅消泡剂。探讨了长链烷基酯链段长短对其稳定性、表面张力、消抑泡性能的影响。结果表明:室温下,甲基丙烯酸十四烷基酯与FB共改性含氢硅油所制消泡剂(P2)稳定性最强,粒径分布最均匀,主要集中在260 nm处,且消抑泡效果最优,在质量分数为5%的十二烷基苯磺酸钠水溶液中消泡时间为6 s,在质量分数为5%的洗衣粉水溶液中消泡时间为4 s,在黑液水溶液(质量分数为30%的木质素溶液)中消泡时间为12 s,消抑泡性能优于国内(RX-504)与德国(850E)消泡剂。     

聚醚改性硅油消泡剂消泡机理研究

以低含氢硅油和经封端及抗氧化处理的单端烯丙基聚醚为原料,在氯铂酸催化下合成聚醚改性聚硅氧烷;再加入气相法白炭黑和二甲基硅油等复配制得硅膏,制得聚醚改性聚硅氧烷消泡剂。与传统的硅油消泡剂做平行对比实验,引入快、慢消泡剂的概念,发现聚醚改性硅油符合"架桥-拉伸"消泡机理,为快消泡剂;同时,讨论了气相法白炭黑可以促进分散效果提高消泡速率的原因。     

有机硅消泡剂KHZ的制备

根据有机硅氧烷的低表面张力的特性研究开发了高效消泡剂KHZ。消泡剂的活性组份是经有机氯硅烷处理的微细二氧化硅固体颗粒,它具有低能表面,在载体和扩展剂协同下易于发泡介质表面铺展,并且难于被加溶,因而消泡和抑泡性都比较高。消泡剂KHZ适用于造纸、石油化工、化学等行业。     

消泡剂气/液界面膜的性质对其消泡性能的影响

参照消泡试验标准ASTM E2407,评价了硅油类、聚醚酯类及聚醚改性聚硅氧烷类3种消泡剂的消/抑泡性能,并采用LB膜天平,测试了消泡剂对模拟起泡体系扩张模量、扩张弹性和扩张黏度的影响。结果表明,消泡剂分子吸附在气/液界面上,降低了界面膜的弹性,减小了界面膜的强度,使得界面膜厚度变薄,泡沫寿命缩短,从而达到破泡效果;消泡剂存在下的界面膜强度在一定时间内不足以形成稳定的泡沫,从而达到抑泡效果。同种消泡剂,在一定质量分数范围内,随质量分数增加,界面膜扩张模量、扩张弹性均降低,消泡剂消/抑泡性能变好;超过某一质量分数时,界面膜扩张模量、扩张弹性基本保持不变,消/抑泡性能也不再增强。不同种消泡剂,界面膜扩张模量及扩张弹性降低幅度越大,消/抑泡性能越好。因此,扩张模量和扩张弹性可以很好地解释消泡剂的消/抑泡效果。     

有机硅消泡剂的制备

采用自制支链硅油,与甲基硅油、硅树脂、白炭黑配合制得硅膏。再将硅膏与Tween-80、Span-60、羧甲基纤维素钠、少量水混匀,然后高速搅拌增稠至半固体状,滴加剩余水和杀菌剂,制得有机硅消泡剂乳液。研究了支链硅油的黏度、支化度及其在硅膏中质量分数对消泡剂性能的影响。结果表明采用黏度2 520 m Pa·s和支化度为1.20的支链硅油,且当其在硅膏中的质量分数为25%时,制得的消泡剂综合性能较佳,消泡时间为60 s,鼓气120 s后的泡沫高度为3 cm。     

(AB)n型聚醚嵌段改性有机硅的合成及其在消泡剂中的应用

在氯铂酸-异丙醇溶液的催化作用下,通过双端基含氢硅油(PHMS)与双烯丙基聚氧乙烯聚氧丙烯醚(AAF)发生硅氢加成反应制备(AB)n型聚醚嵌段改性硅油(PBMS),并对其结构进行红外表征。将PBMS与MQ硅树脂、二甲基硅油、疏水白炭黑等活性组分复配制成消泡剂乳液。从消泡活性物的研制入手,探讨了这些活性组分的质量分数、PBMS的结构、硅油链的长短和聚醚(AAF)相对分子质量(简称分子量,下同)的大小对消泡剂主要应用性能的影响。结果表明:该消泡剂乳液消泡时间7.8 s,抑泡时间达到45.8 min,且在高温(65℃)碱性(pH=12)条件下放置24 h,乳液不分层,不漂油。     

喷雾技术制备含有机硅消泡剂的洗衣粉

介绍了一种高性价比的适用于喷雾技术的液态有机硅消泡剂，并对其喷雾混合添加工艺进行了阐述。通过对使用喷雾技术制备的含有该消泡剂的洗衣粉的泡沫控制性能和稳定性能测试，证明该有机硅消泡剂能有效控制洗衣粉的泡沫，增加低泡洗衣粉的稳定性。     

Model development for the description of silica particles dispersion in silicone polymer

In order to improve the mechanical characteristics of silicone polymer, silica particulate filler can be dispersed in the continuous phase. During the dispersion process, silicone is adsorbed on the particle surfaces, and at the same time, the particles are submitted to breakage and erosion phenomena, modifying therefore their particle size distribution (PSD). A numerical tool, that can simulate the evolution of the silica PSD in polydimethylsiloxane (PDMS) during dispersion, and allows an a priori knowledge of the evolution of the suspension properties, is developed. The comparison between experimental and calculated PSD as well as process viscosity values is presented.The advantage of such a modelization lies in the prediction of the final product properties, or in the design and optimization of a process for obtaining a desired product. This approach also shows the effect of the particle porosity on the product characteristics evolution during the dispersion process. The influence of parameters such as the filler quantity, the stirring speed or the number of silanols sites on the silica surface is also investigated.     

Evaluation of the efficiency of silicone polyether additives as antifoams in crude oil

It is common for crude oil from wells to be accompanied by gas and water because of the presence of natural surfactants in the oil that stabilize the associated water. This causes foaming during processing in gas/oil separators because of the constant agitation and shear forces, which reduce the efficiency of the process and require chemical control by the addition of defoaming additives, or antifoams. In this work, we evaluated the chemical and physicochemical properties of commercial antifoam products based on silicone polyethers along with their efficiency in inhibiting foaming and water/oil (W/O) phase separation. The commercial surfactants were characterized by NMR spectroscopy, size exclusion chromatography, determination of solubility in different solvents, and measurement of the surface and interfacial tensions. A method to test the formation of foam in oil was used to mimic the operating conditions in gas/oil separators. Finally, tests were performed with the addition of aliquots of the additive solutions (30% p/v) in oil to evaluate their efficiency in breaking up the foam under different conditions. The results show that the most polar additive (SL2) was the most efficient in breaking up the foam. Additive SP1, which formed a heterogeneous phase in the oil, was also an efficient foam inhibitor and helped to separate these phases. The antifoam tests showed that these additives did not stabilize W/O emulsions, so they could be used in gravitational separation tanks in the field. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

延迟焦化消泡剂的研制

在延迟焦化装置上,焦炭塔上部易形成大量的泡沫,严重影响焦化装置处理能力和产品质量。因此需使用消泡剂来降低泡沫层的高度,并抑制泡沫的产生。根据延迟焦化装置泡沫层的特点,研制了消泡性能较好的消泡剂。     

疏水型二氧化硅粒子对泡沫体系稳定性的影响

本文对市售二氧化硅粒子进行疏水改性,分别用改性前和改性后的二氧化硅粒子与十二烷基硫酸钠制备泡沫分散液,探讨了二氧化硅粒子亲、疏水性,粒子浓度,粒子在气/液界面膜上的吸附量以及动态拉伸条件下的液膜稳定性的变化规律。研究结果表明,在搅拌条件下,与改性后粒子相比,改性前粒子对维持泡沫体系的起泡性和稳定性作用较强。泡沫稳定性随二氧化硅粒子质量分数的增加而增大,在粒子浓度为0.05%时达到最大值。在拉伸条件下,改性后粒子对液膜稳定性的增强效果优于改性前粒子的作用。改性后二氧化硅粒子质量分数为0.05%的分散液的液膜拉伸最长。     

疏水/亲油丝瓜络制备及在油水分离中的应用

为拓展丝瓜络在油水分离领域的应用,实现农业废弃资源的高值化利用,对天然丝瓜络进行碱-过氧化氢预处理,包括去除蜡质和增大比表面积;配置了纳米二氧化硅和MQ硅树脂疏水分散液,采用超声波辅助浸渍法,以预处理丝瓜络为多孔吸附载体,制得疏水/亲油丝瓜络,并测定其对植物油和水吸附性能、油水混合物的分离效率和重复利用性能。结果表明：浸渍纳米二氧化硅和MQ硅树脂的分散液后,丝瓜络对水和油的接触角分别为140.3°±6°和0°,对植物油和水吸附量分别为4.86g/g和0.28g/g,表现出良好的疏水亲油性能。改性后的丝瓜络对油和水的分离效率分别为76.5%和95.5%,表现出良好的油水分离性能。由于机械挤压破坏了网络结构及部分疏水层的脱落,经过4次过滤后,丝瓜络吸油性能有所降低,影响其重复使用性能。     

PDMS乳液/硅溶胶杂化水分散体系及其复合膜的制备与表征

以聚硅氧烷(PDMS)乳液/硅溶胶杂化水分散液为成膜基质,硅烷偶联剂KH 550为固化剂,制备了双组分水基有机硅涂料;将其固化后得到PDMS/硅溶胶复合膜。通过水分散液的粒径分布及红外光谱分析,研究了水分散液的脱水成膜过程;采用扫描电镜(SEM)和原子力显微镜(AFM)对复合膜的断面和表面形态进行了表征。结果表明:PDMS乳液加入硅溶胶后,粒径分布变宽,粒径略有增加;成膜后,硅溶胶粒子与PDMS长链发生了相互作用,并作为分散相被包埋在PDMS中;复合膜表面形成簇状结构,表面粗糙度随着硅溶胶含量的增加而增加。当硅溶胶与PDMS乳液的固体质量比由10%增加到30%时,复合膜的拉伸强度由0.76MPa升高到3.10MPa,而拉断伸长率从680%下降到470%。     

改性剂种类对白炭黑补强阻尼硅橡胶性能的影响

以阻尼硅橡胶母胶、气相法白炭黑、改性剂为原料,制成了热硫化阻尼硅橡胶。研究了羟基硅油、六甲基环三硅氮烷、乙烯基三乙氧基硅烷(A-151)、γ-氨丙基三乙氧基硅烷(KH 550)、γ-环氧丙氧基丙基三甲氧基硅烷(KH 560)及其并用对阻尼硅橡胶硫化性能、分散性能、力学性能和黏弹性能的影响。结果表明,硅烷偶联剂类改性剂能显著加快混炼胶的硫化速度、缩短硫化时间;羟基硅油、六甲基环三硅氮烷和KH 560作改性剂时白炭黑的分散效果良好,而采用A 151作改性剂时白炭黑填料网络的Payne效应较明显,但在宽温域(-120~100℃)范围内具有温度稳定性;不同改性剂并用对改善白炭黑分散性没有明显的协同作用;改性剂种类对硫化胶的力学性能影响不大;六甲基环三硅氮烷与KH 560并用时,硅橡胶的阻尼性能最高。     

聚醚聚硅氧烷消泡剂HK-013的制备及在染色中的应用

以聚醚聚硅氧烷主组分,考察了乳化剂用量和活性物组分对消泡剂的影响。实验表明,以聚醚聚硅氧烷、疏水白炭黑及聚二甲基硅氧烷为活性组分,配以4.5%的Span-60、Tween-60、Span-80与Tween-80组成的复合乳化剂,制备的HK-013消泡剂的稳定性及消泡性能和抑泡性能较好。在溢流染色生产中进行了应用,证明其可取代目前使用的进口消泡剂。     

Separation of buoyant particles from an aqueous dispersion of corn germ particles using a bubble column

Experiments were conducted to study the use of a bubble column to separate oil from dispersions of corn germ particles in buffered aqueous solution. Particles and aggregates as large as 1 mm which contained oil droplets about in size were suspended in the dispersions. The dispersion was subsequently heated, dosed with enzyme and pumped into a bubble column. Buoyant fine particles and aggregates were lifted through the 2.9 L of the dispersion in a column by nitrogen bubbles and were incorporated into a foam layer at the top of the liquid. The foam drained from the column through a port a few cm above the top of the dispersion and was collected and subsequently centrifuged to separate a free oil layer. The oil yields were comparable to those obtained by centrifuging entire dispersions churned in an incubator/shaker without the bubbling and foaming. With only endogenous surfactant present in the dispersion, the collected foam comprised a quarter of the dispersion mass and about 3/4 of the dispersion's oil (half as a separate oil layer after centrifugation). The rate of free oil collection was the same whether or not the dispersion was bubbled for several hours prior to foam collection.