PREPARATION AND CHARACTERIZATION OF AFFINITY POLYMER BASIC MICROSPHERES BY SOAP-FREE EMULSION POLYMERIZATION

Poly(styrene-co-glycidyl methacrylate) latex microspheres with uniform size and high-density epoxy groups on the surface were prepared by soap-free emulsion polymerization with batch wise operation mode in the presence of 2.2′- azobis(2-methylpropionamidine) dihydrochloride as an initiator.The kinetics of soap-free emulsion polymerization and the effects of polymerization factors were examined.In addition,the optimum polymerization conditions of poly(styrene-co- glycidyl methacrylate) latex microspheres for...

Preparation of Self-crosslinked Fluorocarbon Polymer Emulsion with Core-shell Structure by the Method of Soap-free Emulsion Polymerization

Using methyl methacrylate （MMA）, butyl acrylate（BA） and hexafluorobutyl acrylate（HFBA） as main raw materials, we prepared self-crosslinked fluorocarbon polymer emulsion with core-shell structure via soap-free emulsion polymerization when the conception of particle design and polymer morphology was adopted. Moreover, the influence of mole ratio of BA to MAA, pH value on the oligomer was studied. And the effects of the added amount of oligomer, self-crosslinked monomer and HFBA, mass ratio of BA to MMA, reaction temperature and the initiator on the polymerization technology and the performance of the product, were investigated and optimized. The structure and performance of the fluorocarbon polymer emulsion were characterized and tested with FTIR, TEM, MFT and contact angle and water absorption of the latex film. The experimental results show that the optimal conditions for preparing fluorocarbon polymer emulsion are as follows： for preparing the oligomer, tool ratio of BA to MAA is equal to 1.0 ： 1.60, and pH value is controlled within the range of 8.0 and 9.0; for preparing fluorocarbon polymer emulsion, the added amount of oligmer[P（BA/MANa）] is 6%; mass ratio of BA to MMA is 40 ＂ 60; the added amount of self-crosslinked monomer is 2%, the added amount of HFBA is 15 %; reaction temperature is 80 ℃; the mixture of potassium persulfate and sodium bisulfite is used as the initiator. The film-forming stability of the fluorocarbon polymer emul- sion and the performance of the latex film, which is prepared with the soap-free emulsion polymerization, are better than that prepared with the conventional emulsion polymerization.

Influences of Electrolytes on the Soap-free Emulsion Copolymerization of St-MMA-AA

Monodisperse functional polymer microspheres with different particle size and with clean surface were prepared by batch soap-free emulsion polymerization of styrene, methyl methacrylate and acrylic acid in the presence of salts, and the influences of type and amount of electrolytes on polymerization process and particle morphology were investigated. Results showed that there was a critical concentration for different electrolyte to make polymerization process and the resultant emulsion stable, and the particle size increased with the increase of electrolyte concentration. The effect of metal ions was Ca^2＋〉〉K^＋〉Na^＋〉Li^＋, and the effect of haloids was Br〉Cl〉F. Keywords： Electrolyte, soap-free emulsion polymerization, polystyrene, latex particle morphology.

Synthesis and Characterization of Poly (Methyl Methacrylate)/Polyethylenimine Grafting Core-Shell Nanoparticles for CO2 Adsorption Using Soap-Free Emulsion Copolymerization

Unlike previous emulsion polymerization, we used grafting reactions in soap-free emulsion systems. In this study, we synthesized grafted PMMA/PEI core-shell nanoparticles by varying the MMA/PEI content and molecular weight of PEI (Mn = 600, 8000, and 10,000). The size and morphology of the core-shell nanoparticles were characterized by a particle size analyzer and scanning electron microscopy. The nanoparticles were 178 - 408 nm in diameter and swelled in water or methanol by 30 - 75 nm. The size of the nanoparticles increased with MMA contents, whereas the size distribution progressively became homogeneous with increasing molecular weight of PEI. Lastly, we measured CO2 adsorption capacity of the grafted PMMA/PEI core-shell nanoparticles, and we found the capacity to be limited at a level of 0.69 mg, which occurred for nanoparticles prepared from emulsions at a pH value of 11.

INFLUENCES OF ACID POST-TREATMENT ON THE MORPHOLOGY OF SOAP-FREE P(MMA-EA-MAA)PARTICLES PREPARED BY SEEDED EMULSION POLYMERIZATION

Soap-free poly（methyl methacrylate-ethyl acrylate-methacrylic acid） latex particles with narrow size distribution were synthesized by seeded emulsion polymerization, and the porous particles were created by a stepwise alkali/acid treatment method. Effects of acid treatment conditions on the particle morphology were investigated. Results show that one to three pores were formed inside most of particles after post-treatment. At pH 7.0, when the treatment temperature was lower than 70℃, the size of particles and the volume of pores remained almost unchanged, and these two values increased significantly when the temperature was higher than 70℃. Both the particle size and the pore volume decreased with the increase of initial pH value and treatment time in the acid treatment. As the pH was below 4.0 and the treatment time was longer than 180 min, the particles shrunk in size.

Emulsion Polymerization of Vinyl Acetate in the Presence of a New Cationic Surfactant

In this study, the emulsion homopolymerization system containing vinyl acetate, potassium persulfate, a new cationic polymeric surfactant and water was studied by the applying semi-continuous emulsion polymerization process. The effects of new polymeric emulsifier on the physicochemical properties of obtained vinyl acetate latexes were investigated depending on vinyl acetate percentage in the polymerization recipe, and two thermal initiators in homopolymerization.

The Conductivity of the Mixture of Polyacrylate Emulsion and Cationic Surfactants

A polyacrylate emulsion containing sodium dodecyl sulfate(SDS) as a stabilizer was mixed with cetyltrimethyl ammonium chloride(CTAC) and a cationic surfactant containing an oxide ethylene chain(OEMD-20),respectively.The results of experiment show that the mixtures of CTAC and PAE had higher conductivities than PAE;The mixtures of OEMD-20 had lower conductivities than PAE.

The composition of acid/oil interface in acid oil emulsions

In well stimulation treatments using hydrochloric acid,undesirable water-in-oil emulsion and acid sludge may produce and then cause operational problems in oil field development.The processes intensify in the presence of Fe(Ⅲ),which are from the corroded surfaces of field equipment and/or iron-bearing minerals of the oil reservoir.In order to understand the reasons of the stability of acid emulsions,acid emulsions were prepared by mixing crude oil emulsion with 15% hydrochloric acid solutions with and without Fe(Ⅲ) and then separated into free and upper(water free) and intermediate(with water) layers.It is assumed that the oil phase of the free and upper layers contains the compounds which do not participate in the formation of acid emulsions,and the oil phase of the intermediate layers contains components involved in the formation of oil/acid interface.The composition of the oil phase of each layer of the emulsions was studied.It is found that the asphaltenes with a high content of sulfur,oxygen and metals as well the flocculated material of protonated non-polar oil components are concentrated at the oil/acid interface.In addition to the above,in the presence of Fe(Ⅲ) the Fe(Ⅲ)-based complexes with polar groups of asphaltenes are formed at the acid/oil interface,contributing to the formation of armor films which enhance the emulsion stability.

A New Kind of Void Soap-free P(MMA-EA-MAA) Latex Particles

Soap-free P(MMA-EA-MAA) particles with narrow size distribution were synthesized by seeded emulsion polymerization of methyl methacrylate (MMA), ethyl acrylate (EA) and methacrylic acid (MAA), and large voids inside the particles were generated by alkali posttreatment in the presence of 2-butanone. Results indicated that the size of void and the particle volume were related with the amount of 2-butanone. The generation mechanism of voids was proposed.

A NEW METHOD TO SYNTHESIZE THE CATIONIC GRAFT STARCH

The cationic graft copolymer was synthesized by reversed phase emulsion copolymerization of starch with diallydimethyl ammoniumlchlorid (DADMAC) and acrylamide(AM). The copolymerization was carried out using (NH4)2S2O8-NH2CONH2 redox as initiator and selecting Span-20 as emulsifier. The effects of emulsifier content in oil phase, volume ratio of oil to water, initiator concentration and mole ratio of DADMAC to AM on the graft copolymerization were discussed. The optimum condition of synthetics was found with the orthogonal test method.

Synthesis of ABA Type Block Copolymers of Poly(Ethylene Glycol)and Poly(Dodecyl Vinyl Ether)and Its Using as Surfactant in Emulsion Polymerization

A poly(ethylene glycol) (PEG) based macroinitiator (MI) with terminal chloride atom at both ends was prepared by the reaction of PEG-400 with chloroacetyl chloride and used for the cationic polymerization of dodecyl vinyl ether (DVE) yielding ABA type block copolymer. The block copolymer was then used as the surfactant for the emulsion polymerization of vinyl acetate and styrene in the presence of potassium persulfate as an initiator. The effects of new polymeric emulsifier on the physicochemical properties of obtained latexes were investigated depending on surfactant percentage in homopolymerizations.

阳离子分散松香胶/AKD乳液/壳聚糖联合提高麻浆与烟梗浆配抄滤嘴棒用纸的疏水疏油性能

以麻浆和烟梗浆为原料,抄造滤嘴棒用纸。通过浆内添加施胶剂〔阳离子分散松香胶和烷基烯酮二聚体(AKD)乳液〕和表面涂布壳聚糖的方法,提高滤嘴棒用纸的疏水疏油性能。探究施胶剂添加量和壳聚糖涂布量对滤嘴棒用纸防水性能、防油等级和物理性能的影响。研究结果表明:当浆内阳离子分散松香胶和AKD乳液添加量均为2%(相对绝干浆)时,滤嘴棒用纸的接触角为128.8°,60 s时滤嘴棒用纸的可勃值为24.30 g/m^(2);当壳聚糖涂布量为20 g/m^(2)时,滤嘴棒用纸的防油等级为12级。

阳离子型苯丙乳液施胶剂的改性及物性研究

为改善阳离子型苯丙乳液施胶剂的环保性,采用来源广泛、成膜性好且易生物降解的明胶和壳聚糖进行复合改性,确定了壳聚糖用量为阳离子型苯丙乳液施胶剂质量的0.35%,明胶用量应不高于0.35%,重点研究了明胶用量对明胶-壳聚糖改性阳离子型苯丙乳液施胶剂的分散性、pH、表面张力和固含量等物性的影响,结果表明:随着明胶用量的逐渐增加,明胶-壳聚糖改性阳离子型苯丙乳液施胶剂的静置稳定性、离心稳定性高,分散性为一级,pH保持2.30不变,固含量变化大,而表面张力和纸张白度变化小。

基于油酸咪唑啉组分的阳离子加脂剂制备

油酸咪唑啉作为阳离子加脂剂的活性成分,其由油酸和羟乙基乙二胺进行合成;研究将油酸咪唑啉与中性油复合后,通过相转化法制备获得乳液型阳离子皮革加脂剂(GC)。对油酸咪唑啉组分及GC进行分析,并与市售阳离子加脂剂FC进行对比。结果表明,GC具有较好的乳化稳定性,其乳液平均粒径为2.21μm,小于FC(3.21μm);在黄牛皮沙发革的加脂应用中,采用GC加脂的坯革相较于FC具有更好的油润感、手感持久度、耐光性及物理力学性能。实验表明,GC是一种良好的阳离子加脂剂。

高取代度阳离子淀粉基苯丙乳液的合成和应用研究

以苯乙烯(St)、丙烯酸正丁酯(BA)、丙烯酸叔丁酯(tBA)为单体,H2O2-FeSO4为引发体系,高取代度阳离子淀粉(HCS)为乳化剂,开展了苯丙表面施胶剂的无皂乳液聚合。探讨了HCS的用量、分子量(以特性黏度表示)、取代度对乳液聚合的影响,使用多种方法评价了乳液的理化性能与应用性能。所制备得的高取代度阳离子淀粉基苯丙乳液胶粒平均粒径小(126.2 nm)、正电性强(Zeta电位为25.8 mV)、贮存稳定性优良;将其应用在瓦楞原纸上,施胶纸张的Cobb值为21.6 g/m^(2),水滴接触角达121.6°,与低取代度阳离子淀粉基苯丙乳液相比,其应用效果具有明显优势。研究对其能赋予纸张更佳施胶效果的原因也提出了机理性的解释。

Synthesis of submicron-sized peanut-shaped poly(methyl methacrylate)/polystyrene particles by seeded soap-free emulsion polymerization

Submicron-sized peanut-shaped poly（methyl methacrylate）/polystyrene （PMMA/PS） particles were successfully synthesized by seeded soap-free emulsion polymerization of styrene on the spherical crosslinked PMMA seed particles. The obtained peanut- shaped particles showed a novel internal morphology： PS phase formed one domain which linked to the other domain having PMMA core encased by PS shell.

PREPARATION OF MICRON-SIZED NONSPHERICAL POLYSTYRENE/POLY(STYRENE-co-ETHYLENEGLYCOL DIMETHACRYLATE) PARTICLES BY SEEDED SOAP-FREE EMULSION POLYMERIZATION

Micron-sized nonspherical polymer particles having different morphologies were synthesized by seeded soap-free emulsion polymerization of styrene （St） and ethyleneglycol dimethacrylate （EGDMA, used as a crosslinker） on spherical, linear polystyrene （PS） seed particles. The morphology of the resulting PS/poly（St-co-EGDMA） particles was dependent on the crosslinker concentration and polymerization temperature.

关注0.1%CsA阳离子乳剂在眼表免疫性疾病中的合理选择及应用

眼表免疫性疾病(OSID)是由全身免疫性疾病引起,或是有局部免疫系统参与的慢性炎性眼部疾病,通过在眼及其附属器产生持续性炎症而引起泪液高渗环境和眼表上皮损伤,从而导致或加重干眼。常见的免疫炎性相关眼表疾病包括春季角结膜炎(VKC)、干燥综合征、移植物抗宿主病、干眼、免疫性角膜疾病等,严重影响患者的视觉功能和生活质量。目前,OSID主要采用人工泪液和糖皮质激素滴眼液进行治疗,但治疗效果欠佳且不良反应风险较大,因此OSID的有效治疗一直面临很大挑战。环孢素A(CsA)是一种临床常用的免疫抑制剂,具有很强的免疫调节作用,但由于其既有眼用剂型的通透性低,在临床上的应用受到一定限制。CsA眼用制剂的研发改变了OSID的治疗策略,近来研发的0.1%CsA阳离子乳剂显著提高了CsA局部应用的作用效果及安全性,值得临床医生关注。眼科医生应该充分认识各种OSID的免疫相关病理机制,充分了解0.1%CsA阳离子乳剂对OSID的疗效、适应证、眼表局部应用方法、不良反应等,进而在各种OSID的治疗中进行合理选择。

反相乳液聚合法制备阳离子聚丙烯酰胺乳液及其应用

以丙烯酰胺(AM)、甲基丙烯酰氧乙基三甲基氯化铵(DMC)为功能性单体,在氧化-还原引发体系下,通过反相乳液聚合方法,成功制备了乳液型阳离子聚丙烯酰胺。对比了自制乳液样品(CPAMZ1)、CPAMZ1与无机絮凝剂聚铝(PAC)复配乳液样品和市售成熟乳液产品(ASC1010)在市政污泥废水处理中的应用效果。研究结果表明,CPAMZ1处理污泥的效率高于ASC1010,以透光率为指标,前者絮凝效果增强了20.58%;对比CPAMZ1样品,CPAMZ1/PAC复配液(CP/PAC)的絮凝效果增强了13.64%。在污泥废水处理中,乳液型絮凝剂适合与无机絮凝剂进行配合使用。