Influence of Suspension Parameters on Water Absorbency of Starch-g-poly( sodium acrylate) Synthesized by Inverse Suspension Polymerization

Superabsorbents starch grafted sodium polyacrylate was prepared by inverse suspension polymerization, using toluene as the continuous phase, potassium persulfate as the initiator. The effect of suspension parameters, such as volume ratio of continuous phase and dispersed phase, type and dosage of suspending agents, on water absorbency of the starch grafted polymer was studied. Different starch derivatives were also investigated. Superabsorbents made of cationic starch has higher water absorbency than that made of native corn starch.

Monitor of Polymerization of Inverse Microemulsions Containing Methyl Methacrylate and Acrylic Acid

The polymerization of the inverse microemulsions composed of methyl methacrylate,acrylic acid, sodium dodecyl sulfate and water was monitored by refractometer, conductometer and time-resolved light scattering device. The results showed that refractive index, conductivity or intensity distribution of scattered light changed along with polymerization, and different processes of polymerization could be identified.

Investigation on the Inverse Emulsion Polymerization of Acrylic Acid

Polyacrylic acid particles in nano-scale were synthesized using an inverse (W/O) emulsion polymerization method. The particle size and size change of inverse micelles which solubilize a part of monomer solution was monitored by PCS (photon correlation spectroscopy) and the particles of polyacrylic acid were viewed in scanning electron microscope for the first time. It was concluded that the inverse micelles were primarily the polymerization reaction sites.

INFLUENCES OF WATER-SOLUBLE CATIONIC MONOMERS ON THE POLYMERIZATION RATE IN THE INVERSE EMULSION

This investigation deals with the free radical polymerization both of (2-methacryloyloxyethyl) trimethyl ammonium chloride (QACEMA) and of diallyldimethyl ammonium chloride (DADMAC) in inverse emulsion. The influences of some factors, such as the concentration of monomers, initiator and emulsifier are discussed. The polymerization rate equations of above two monomers can be written as follows: R(p) = k[M](1.21)[I](0.82)[E](0.57) (for QACEMA) R(p) = k'[M](1.34)[I](0.90)[E](0.62) (for DADMAC)

Mechanism and Modeling for Polymerization of Acrylamide in Inverse Microemulsions

After discussion on the mechanism of polymer particle nucleation and growth in inverse microemulsion polymerization, a schematic physical model for polymerization of acrylamide in inverse microemulsions was presented. Furthermore, several key problems in mathematically modeling of inverse microemulsion polymerization were pointed out.

THE PREPARATION OF DOXORUBICIN-POLYVINYLPYRROLIDONE-NANOPARTICLES BY INVERSE EMULSION POLYMERIZATION

Doxorubicin-loaded nanoparticles, using doxorubicin （ADM） as model drug and vinylpyrrolidone as matrix, were prepared by inverse emulsion polymerization in the paper. The nanoparticles were characterized by telescope electron microscopy （TEM）, laser light scattering technique （LLS） and infrared spectrum （IR）. LLS test showed that the optimal prepared ADM-loaded nanoparticles had an average size 18.8nm and a narrow size distribution between 15nm and 32nm, which was consistent with the result obtained by TEM. And 1R results indicated that the nanoparticles consisted of ADM and polyvinylpyrrolidone （PVP）.

Synthesis of Acrylic Acid/Kaoline Powder Superabsorbent Composite by Inverse-suspending Polymerization

An acrylic acid/kaoline powder superabsorbent composite with a water absorbency of the superabsorbent composite about 1/800 was synthesized by inverse\|suspending polymerization reaction between acrylic acid monomer and kaoline ultrafine powder. The influence of the dispersant agent on the configuration of the products in the inverse suspension polymerization is investigated. The influences of the kaoline powder,cross\|linker,initiator,neutralization degree and the volume ratio of oil to water phase on the water absorbency of the superabsorbent composites are discussed in the paper.

PREPARATION AND STUDY ON SILICONE ACRYLATE MICRO-EMULSION OF MULTIPOLYMER

A silicone acrylate micro-emulsion of multipolymer was prepared by seed emulsion polymerization. The effects of polymerization process, emulsifier rate and amount, initiator rate and amount, polymerization temperature, functional monomers, titration time on performances of emulsion have been discussed in detail.

STUDY ON SYNTHESIS OF AMPHOTERIC POLYACRYLAMIDE IN INVERSE EMULSION

Amphoteric polyacrylamide was prepared first by the copolymerization of acrylamide with sodium acrylate and then through Mannich reaction.The copolymerization was carried out with a redox initiation system using the method of inverse emulsion polymerization.In this paper the reaction conditions and factors that affect emulsion stability were studied.Experiments show that a stable latex can be obtained under the following conditions:anionic degree is five percent,the ratio among acrylamide,formaldehyde and dimethylamine is 1∶1∶1.2,reaction temperature is 45 ℃,reaction time lasts four hours,and pH equals 5.0.The amphoteric copolymer has a higher molecular weight and cationic degree,so it is an ideal filler retention and drainage aid in paper making.

Preparation of Chitosan-g-PAM PS in H_2O/scCO_2 Inverse Emulsion

Chitosan （CS） was successfully modified in supercritical carbon dioxide （ scCOz ） by grafting method to enhance its water solubility. In this work, a three.arm star-like fluorinated polymer was synthesized by atom transfer radical polymerization （ ATRP ） method and applied as a surfactant in supereriticul carbon dioxide （scCO2 ）. Then 2-acrylamido-2-methyl propane sulfonie acid （AMPS） was grafted onto CS （CS-g-PAMPS） in H2O/scCO2 inverse emulsion. The effects of mass ratio of water and surfactants （Rw/s ） and pressure of scCO2 on the grafting reaction were investigated. The grafting rate, partide size, and dispersity in water of CS-g-PAMPS varied greatly as Rw/s and pressure of scCO2 changed. It could be found that the value of Rw/s at 12 and the pressure of scCO2 at 30 MPa were the optimum conditions for the grafting reaction. CS-g-PAMPS prepared in this reaction system has higher grafting rate, smaller particle sizes, and better dispersity in water than those prepared via conventional methods.

Numerical Study on Microbial Depolymerization Process of Xenobiotic Polymer

This study demonstrates mathematical analysis of biodegradation processes of xenobiotic polymers. A model for microbial population is based on the fact that growth rate of microorganisms is proportional to the microbial population and consumption rate of parts of carbon sources. The model is paired with a model for weight distribution. Those models lead to inverse problems for a molecular factor and a time factor of degradation rate. Solution of the inverse problems allows us to simulate the biodegra-dation process.

适用于LAS系统的全液体隔离液体系

固井施工过程中,在注入水泥浆前,需要先泵入一定量的隔离液,在海洋固井现场施工作业过程中,隔离液配制一般需要繁重的人工劳作,劳动强度大,作业效率低,加量不准确。为解决上述问题,用液体添加剂代替固体添加剂,通过LAS材料添加系统将材料混配作业,从传统的重体力劳动转化为智能化操作,降低作业强度,提高固井作业效率与降低人员成本。通过反相乳液聚合制备了一种液体隔离剂C-S70L,以它为主剂,构建了一套适用于液体加料系统(LAS)的隔离液体系。该体系推荐使用温度为20~120℃,适用密度为1.30~1.70 g/cm^(3);具有良好的悬浮稳定性(热滚后无沉降)、流变可调、失水可控以及相容性好的特点。

新型低界面张力纳米微球调驱剂的合成与性能研究

聚丙烯酰胺纳米微球调驱剂作为一种新型的纳米驱油材料,在油田提高采收率方面取得了广泛应用。但是,目前使用的聚丙烯酰胺纳米微球功能主要以封堵为主,存在单体固含量低、水溶液吸水膨胀速度过快、驱油和降低表界面张力功能较差等问题。利用反相乳液聚合法,以白油为油相,2-丙烯酰胺-2-甲基丙磺酸(AMPS)、丙烯酰胺(AM)混合单体为水相,油酸/双子聚醚/OP-10混合表面活性剂为乳化剂,根据三元相图确定油相/乳化剂/水相三相的最佳配比(质量分数)为33.93%/24.87%/41.2%,以甲叉双丙烯酰胺(MBA)作为交联剂,在35℃利用氧化-还原剂聚合获得了既具有封堵功能,又具有超低表界面张力、高洗油效率的新型纳米微球调驱剂。工艺优化实验确定最佳的合成条件为单体配比m(AM)∶m(AMPS)为8∶1,交联剂质量分数为0.1%,氧化-还原剂质量分数为0.3%,搅拌速度为450 r/min。对聚合物纳米微球进行表征和性能评价,结果表明,其固含量为20.1%,粒径为54 nm,纳米微球封堵率可达95.1%,用其0.2%的水溶液测得界面张力为0.332 mN/m,洗油效率高达89.13%,为实施油田调驱提供了一种新材料。

高分子化学实验“反相乳液法制备聚丙烯酰胺微球”的设计

实验教学作为理论教学的延伸与拓展,对强化学生理论知识点、提升实验实践能力具有重大促进作用。为满足人才培养的最新要求,现对高分子化学实验内容进行优化,设计“反相乳液法制备聚丙烯酰胺微球”实验项目。实验过程通过改变单体浓度、引发剂加量等多个实验条件,引导学生思考不同实验条件对产物粒径的影响,加深学生对反相乳液聚合机理的理解。通过该实验,学生还能够掌握使用激光散射系统测定产物粒径的方法。

聚丙烯酰胺树脂的反相悬浮聚合制备及吸水性能研究

以丙烯酰胺为单体、过硫酸铵为引发剂、单硬脂酸甘油酯为分散剂、N,N-亚甲基双丙烯酰胺为交联剂,采用反相悬浮聚合法制备了聚丙烯酰胺吸水树脂。考察了分散剂、交联剂、引发剂、单体浓度、油水比、反应温度、反应时间等因素对吸水倍率和产率的影响。结果表明,单硬脂酸甘油酯用量为3%、N,N-亚甲基双丙烯酰胺为0.12%、过硫酸铵为0.5%、单体浓度为30%、油水比范围为4:1~6:1、反应温度在70~75℃、反应时间为4 h时,聚丙烯酰胺树脂的吸水倍率和产率较高。利用傅里叶变换红外光谱仪、热重分析仪和凝胶渗透色谱仪对产物进行了测试表征。

海上油田开发用抗温抗盐乳液聚合物研制与性能评价

为满足海上油田开发对聚合物溶解速度、抗温和抗盐性能的要求,使用自制的高效聚合物乳化剂和热稳定剂,采用低温复合引发体系多段引发,制备了超高相对分子质量的速溶抗温抗盐型乳液聚合物,分析了制备工艺,助溶剂、功能单体和热稳定剂加量对聚合物性能的影响。结果表明,通过工艺优化可制备得到相对分子质量2200万~2400万的聚合物,尿素和硫酸钠可显著提高超高相对分子质量抗温抗盐乳液聚合物的溶解速度;聚合时添加N,N-二甲基丙烯酰胺、自制热稳定剂和2-丙烯酰胺-2-甲基丙磺酸钠,可显著提高聚合物的抗温抗盐性能。采用电镜、激光粒度仪、GPC和TGA等方法,评价了超高相对分子质量抗温抗盐型乳液聚合物的结构及性能,结果表明,制备的聚合物乳胶粒粒径分布均匀、相对分子质量分布窄和耐温性能好,在矿化度35000 mg/L、温度75℃条件下,乳液聚合物30 d的黏度保留率大于90%。研究表明,超高相对分子质量抗温抗盐型乳液聚合物具有速溶、相对分子质量高和抗温抗盐性能好的特点,可以用于海上油田驱油开发。

反相乳液聚合法制备缔合型耐盐聚合物及其流变性能

以丙烯酰胺(AM)、2-丙烯酰胺-十二烷基磺酸钠(AMC_(12)S)、疏水单体29-(4-辛基苯氧基)-3,6,9,12,15,18,21,24,27-壬氧烷酮基甲基丙烯酸酯(GTE-10)为原料,通过反相乳液聚合法制备了一种缔合型耐盐聚合物p(AM/AMC_(12)S/GTE-10)。通过FTIR、~1HNMR、SEM、TEM及激光粒度分析仪对其结构和形貌进行了表征,并对其流变性能、触变性能和黏弹性进行了评价。结果表明,疏水单体GTE-10成功引入聚合物中,聚合完成后的乳液粒径分布集中且均一,盐(NaCl、CaCl_(2))的加入使p(AM/AMC_(12)S/GTE-10)分子聚集态更紧密,形成的空间网络结构更稳定。质量分数为0.7%的p(AM/AMC12S/GTE-10)聚合物水溶液在140℃时表现出较好的耐温性能;在120℃、170s^(–1)条件下剪切1 h,在质量浓度为20000 mg/L的NaCl和CaCl_(2)水溶液中分别配制质量分数0.7%的聚合物溶液,其表观黏度分别为64.8和54.1m Pa·s;聚合物具有较好的剪切恢复性能;盐水条件下储能模量大于损耗模量,金属离子与苯氧乙烯基发生络合反应,使分子间作用力增强,形成的空间结构更稳定且难被破坏,黏弹性更高。

反相乳液聚合法制备抗盐型两性共聚物P(AM-AA-AMPS-DAC)乳液

本文以丙烯酰胺(AM)、丙烯酸(AA)、2-丙烯酰胺-2-甲基丙磺酸(AMPS)、丙烯酰氧乙基三甲基氯化铵(DAC)为单体,白油(W1-TB)为油相,Span-80和Tween-80为乳化剂,过硫酸铵(APS)为引发剂,采用反相乳液聚合法制备两性丙烯酰胺共聚物P(AM-AA-AMPS-DAC),重点探讨油水比、乳化剂用量、引发剂用量、单体用量以及p H值对共聚物表观黏度的影响。实验结果表明,当油水比为1∶1,乳化剂用量为3%(以体系总质量计,下同),引发剂用量为0.06%,单体用量为35%,初始引发温度为60℃,pH值为7时,制备的两性丙烯酰胺共聚物乳液在去离子水中的表观黏度值为150mPa·s,在矿化度为30000 mg/L盐水中的表观黏度值为60 mPa·s,其黏度保留率为40%,呈现出较好的抗盐性。

四元共聚抗高温耐盐粉体降失水剂的制备及性能研究

以2-丙烯酰胺-2-甲基丙磺酸(AMPS)、N,N-二甲基丙烯酰胺(DMAA)、马来酸酐(MA)和甲基丙烯磺酸钠(SMAS)等为原料,采用反相乳液聚合法并引入非离子型乳化剂异构十三醇聚氧乙烯醚和司班80合成了一种抗高温耐盐四元共聚物粉体降失水剂ADMS。利用FT-IR、NMR、TG和GPC对共聚物的结构和热稳定性进行表征,并对ADMS进行了性能评价。结果表明,4种功能单体均参与了反应,ADMS的重均分子质量达448198,耐温可达320℃;ADMS抗温能力良好,使用温度在30~200℃;200℃时,添加3%ADMS的淡水基水泥浆失水量为48 mL;ADMS抗盐能力良好,在半饱和盐水和饱和盐水基水泥浆中分别添加4%和5%的ADMS可控制失水量在50 mL以内;ADMS对水泥浆稠化时间、水泥石抗压强度等无不利影响。

钻井液用反相乳液聚合物增黏剂的合成及评价

以两性离子单体N-甲基二烯丙基丙磺酸、N,N-二甲基丙烯酰胺、N-乙烯基己内酰胺为聚合单体,以偶氮二异丁脒盐酸盐(AIBA)为引发剂,采用反相乳液聚合法制备了增黏剂乳液DVL-1,有效固相质量分数为33%。利用FTIR、^(1)H NMR、TG-DTA等方法对DVL-1进行了表征测试,并对产物的增黏性能、抗高温抗盐性能等进行了评价。结果表明:质量分数为1%的DVL-1水溶液表观黏度可达17.4 m Pa·s。180℃/16 h高温老化后,溶液黏度保持率高达52.9%。通过观察DVL-1在溶液中的空间立体形态及对Zeta电位的数据分析,探讨了聚合物起效机理,DVL-1的抗温性能主要归因于分子结构中稳定的主链及侧链刚性基团,两性离子结构降低了聚合物对高价盐离子的敏感性,抑制了侧链的持续卷曲,抗盐性能得到显著提升。