Synthesis and Characterization of Fluorine-containing Polyacrylate Emulsion with Core-Shell Structure

A fluorine-containing polyacrylate copolymer emulsion was synthesized by a seed emulsion polymerization method, in which methyl methacrylate （MMA） and butyl acrylate （BA） were used as main monomers and hexafluorobutyl methacrylate （HFMA） as fluorine-containing monomer. The structure and properties were characterized by Fourier transform infrared spectrum （FT-IR）, transmission electron microscopy （TEM）, particle size analysis, X-ray photoelectron spectroscopy （XPS）, contact angle （CA）, differential scanning calorimetry （DSC） and thermogravimetry （TG） analysis. The FTIR and TEM results showed that HFMA was effectively involved in the emulsion copolymerization, and the formed emulsion particles had a core-shell structure and a narrow particle size distribution. XPS and CA analysis revealed that a gradient concentration of fluorine existed in the depth profile of fluorine-containing emulsion film which was richer in fluorine and more hydrophobic in one side. DSC and TG analysis also showed that a clear core-shell structure existed in the fluorine-containing emulsion particles, and their film showed higher thermal stability than that of fluorine-free emulsion.

PHOTOINITIATED INVERSE EMULSION POLYMERIZATION OF SODIUM ACRYLATE

Photoinitiated inverse emulsion polymerization of sodium acrylate(AANa)in kerosene was carried out at room orlower temperature,using 2,2-dimethoxy-2-phenylacetophenone(DMPA)as the initiator.Kinetic investigations indicated thatthe polymerization could be completed in about 30 min and produce polymer with high molecular weight(10~6～10~7).It wasfound that monomer droplets are the main sites for the polymerization(nucleation).With the increase of DMPAconcentration,polymerization rate(R_p)reaches a maximum value while molecular weight of the produced polymer has anadverse result,but the dependence of R_p on incident light intensity is similar.Influences of other parameters such asmonomer concentration,emulsifier content and reaction temperature,etc.were also studied.At lower pH values of waterphase,R_p depends strongly on the pH due to the electrostatic interaction between the ionized radicals and the monomer.Athigher pH,R_p shows a slight dependence on pH.

Nonionic Polymerizable Emulsifier in High-Solids-Content Acrylate Emulsion Polymerization

Stable high-solids-content acrylate emulsion were obtained with a nonionic polymerizable emulsifier allyloxy nonylphenoxy poly （ethyleneoxy） （10） ether （ANPEO10）, and a conventional emulsifier OP-10 as a reference sample. 1H NMR proves that the polymerizable emulsifier ANPEO10 has been incorporated into the resulted acrylate polymers. TEM demonstrates that there are some differences in the particle morphologies. AFM proves that the polymerizable emulsifier ANPEO10 migrating to the surface of the emulsion film was much less than the conventional emulsifier OP-10. The polymerizable emulsifier ANPEO10 can enhance the adhesion with glass plate compared to the conventional emulsifier. Furthermore, with increasing amount of emulsifier, the surface free energy of the films first decreased and then increased, and the adhesion with glass plate is initially enhanced and then attenuated. The water-resistance and solvent-resistance of the films prepared by the polymerizable emulsifier ANPEO10 are superior to those prepared by the conventional emulsifier OP-10.

Design and Synthesis of Novel Fluorine-containing Acrylates

A series of novel fluorine-containing acrylates 6a-6g were synthesized via the condensation of ethyl cyanoacetate and trifluoroacetic anhydride, followed by chloridization and the coupling reaction with amines. These new compounds exhibited some biological activity as preliminary bioassay indicated. A plausible reaction mechanism was outlined and discussed.

SEED SEMICONTINUOUS EMULSION MULTI-COPOLYMERIZATION OF (METH) ACRYLATES WITH HIGH-SOLID CONTENT: EFFECT OF THE OPERATION CONDITIONS

The seeded semicontinuous emulsion multi-copolymerization of butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), methyl methacrylate (MMA), 2-hydroxyl propyl acrylate (HOPA) and acrylic acid (AA) was used to prepare the acrylic latexes with high-solid content. The effects of monomer emulsion feed rates (R(a)) and (R/E)(E) values, the ratio of emulsifier amount between the initial charge (R) and the addition monomer emulsion (E), on the polymerization reaction features, the viscosities, surface tensions,particle sizes and particle sizes distributions of latexes, T-g and the insoluble fractions of films, the 180 degrees peel strength, tack and holding power of pressure-sensitive adhesive (PSA) tapes, prepared from the latexes, were studied. Experimental study shows that the grafting and crosslinking fraction in the PSA tapes must be controlled within a suitable range to keep the balance of the 180 degrees peel strength, tack and holding power.

FT-IR Study on Crosslin king Reaction of Acrylates Copolymer Emulsions

Introduction The emulsion of acrylate copolymers with actively functional groups have been widely developed and used as coating, adhesive and handling agent in spinning and weaving industry. Bessett, D. R. et al. studied the thermoset of N-(isobutoxymethyl) acrylamide by thermal evolution analysis and thermal gas chromatogram. Krejcar,

STUDY ON THE FORMATION MECHANISM OF MONODISPERSE PARTICLES IN THE EMULSIFIER-FREE EMULSION POLYMEAIZATION OF METHYL METHACRYLATE AND BUTYL ACRYLATE

The formation mechanism of monodisperse polymer latex particles in the emulsifier-free emulsion polymerizationof methyl methacrylate and butyl acrylate with potassium persulfate as initiator was investigated. A multi-step formationmechanism for the monodisperse polymer particles was proposed. The nucleation mechanism is considered to be thecoagulation of the precursor particles by homogeneous nucleation when the primary particles reach a critical size with highsurface charge density and sufficient stability. It had been proved by a special experiment that the early latex particles formedby the coagulation were stable. The primary particles grow by absorbing monomers and radicals in the polymerization systemand then become colloidally unstable again due to the understandable decrease of particle surface charge density, which leadsto the aggregation of the growing particles and the formation of larger latex pedicles therefrom. Aner the nucleation period,the preferential aggregation of the smaller particles in the propagation process leads to the change of the particles towards auniform size and narrower particle size distribution. The coexistence and competition of homogeneous nucleation,coagulation, propagation and aggregation result in the increase of the polydispersity index (U = D_(43)/D_(10)) in the first Stage,then its decrease in the later stage because of the competition of propagation and aggregation, and the gradual formation ofthe monodisperse particles.

Preparation of self-crosslinked acrylate emulsion with high elasticity and its rheological properties

Using butyl acrylate(BA),methyl methacrylate(MMA),methacrylic acid(MAA) and mixed emulsifier as raw materials,the self-crosslinked emulsion was prepared via pre-emulsified and semi-continuous seeded emulsion polymerization technology in the presence of N-hydroxymethyl acrylamide and poly solidum maleate. The influence of mass ratio of BA to MMA,amount of N-hydroxymethyl acrylamide and poly solidum maleate on the rheological properties of the self-crosslinked emulsion was studied. Possible cross-linked mechanism of self-crosslinked monomer was investigated. And the relationship between emulsion viscosity and shear rate was investigated. The results show that the self-crosslinked acrylate emulsion with high elasticity can be synthesized when the mass fractions of BA is 60%,MMA is 40%,and added amount of N-hydroxymethyl acrylamide is 2.5%-3.0% and added amount of poly solidum maleate is 0.3%-0.4%. The self-crosslinkage process of N-hydroxymethyl acrylamide involves two steps. One is copolymerization of N-hydroxymethyl acrylamide and acrylate,the other is cross-linkage among polymer molecules via condensation reaction of methylol. The emulsion is of rheological properties of pseudo-plastic fluid and belongs to non-Newtonian fluid.

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.

Application of waterborne acrylic emulsions in coated controlled release fertilizer using reacted layer technology

Waterborne acrylic emulsions modified with organic siloxanes and aziridine crosslinker were synthesized and applied as coating of controlled release fertilizer. The free films were characterized and the nutrient release profiles of the coated fertilizers were determined. The results show that methyl silicone oil and methylsilanolate sodium could not improve water resistance performance and glass transition temperature Tgof coatings, while the firmness is enhanced. Aziridine crosslinker improves the water resistance performance, firmness and Tg. Incorporation of methyl silicone oil and aziridine crosslinker gives an excellent aqueous acrylic emulsion for coated controlled release fertilizer, with the 30-day cumulative nutrient release reduced to 16% and an estimated nutrient release duration over 190 days. Therefore, this waterborne coating is promising to meet the requirements for controlled release of nutrient and environmental protection.

EFFECTS OF ω-ACRYLOYL POLY (ETHYLENE OXIDE) MACROMONOMER ON EMULSIFIER-FREE EMULSI0N COPOLYMERIZATION OF METHYL METHACRYLATE AND n-BUTYL ACRYLATE

Well-defined nonionic hydrophilic ω-acryloyl poly(ethylene oxide) macro-monomer (PEO-A) has been prepared by living anionic polymerization of ethylene oxidewith diphenyl methyl potassium as the initiator and acryloyl chloride as the reaction termi-nating agent. The polymer was characterized by FTIR and SEC. The emulsifier-free emul-sion polymerization of methyl methacrylate (MMA) and n-butyl acrylate (BA) containingvarious concentrations of PEO-A was studied. In all cases stable emulsion coplymerizationsof MMA and BA were obtained. The stabilizing effect was found to be dependent on themolecular weight and the feed amount of the macromonomer.

Synthesis and properties of acrylate latex modified by vinyl alkoxy siloxane

Acrylate latex modified by vinyl triisopropoxy silane (C-1706) was synthesized by seeded emulsion polymerization with anionic emulsifier sodium dodecyl sulphonate(SDS) and nonionic emulsifier OP-10 as the multiple emulsifiers at (78±2) ℃. The effects of different factors, such as the emulsifier, C-1706 monomer and its feeding manner on the properties of acrylate latex modified by C-1706 were investigated. The particle size distribution and the structure, the configuration, the weather durability and stain resistance of copolymer latex were characterized by particle size analyzer, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope(TEM), scanning electron microscope(SEM) and ultraviolet aging instrument respectively. The results show that SDS to OP-10 as multiple emulsifiers can lead to coordinated efficiency, the optimal emulsifier dosage is 2.4%?3.2%(mass fraction), and the mass ratio of SDS to OP-10 is 1?1? 1?2. The seeded emulsion polymerization can effectively introduce a organic-siloxane bonding in a macromolecule inter polymer, and the obtained acrylate latex modified by organic-siloxane possesses narrow distribution of particle size with mean diameter of 51.8?76.6 nm and has the excellent properties in weather durability and stain-resistance especially.

SYNTHESIS AND CHARACTERIZATION OF A NOVEL FLUORINE-CONTAINING HYDROPHOBICALLY ASSOCIATING POLYMER

In this article, the synthesis and characterization of a novel fluoromonomer and its copolymer with acrylamide is reported. 2-perfluoroamyl-4-hydroxylquinoline 2 was synthesized from ethyl 2, 2-dihydroperfluoroheptanoate in high yields. The monomer 4 was then synthesized from 2 in two steps readily in high yields. Synthesis and characterization of copolymers of acrylamide (AM) and the fluoromonomer were investigated. The composition and intrinsic viscosity of these copolymers were studied. It was found that the rheological properties of aqueous solutions of polyacrylamide were modified significantly when a small proportion of the fluoromonomer 4 was incorporated on investigating the viscosity-concentration profiles, pseudoplasticity of these solutions and the effect of the presence of surfactant. These results could be explained by the hydrophobic association of the fluorocarbon segments in the aqueous solutions of these copolymers.

Synthesis of Novel Fluorinated Acrylate Co-polymers and Their Application on Cotton Fabrics

Two novel fluorinated acrylate monomers 4a and 4b containing perfluorohexyl group were designed and synthesized starting from 4-allylanisole and perfluorohexyl iodide.The monomers 4a and 4b were then copolymerized with octadecyl acrylate and 2-hydroxyethyl acrylate by emulsion polymerization to give copolymers PFA 1 and PFA 2 respectively.The co-polymers were characterized by FT-IR and their heat stability was measured by TGA.The surface properties of PFA 1 and PFA 2 were studied by applying on cotton fabrics.The treated cotton fabrics showed good water-repellent property,and the contact angles for water reached 142° for PFA 1 and 136° for PFA 2.

Preparation of Styrene-acrylate Latex Used in Ultralow VOC Building Internal Wall Coating

Styrene-acrylate latex with high glass transition temperature （T）, low minimum film forming temperature（MFT） and good stability was prepared via core-shell emulsion polymerization. With semicontinuous process, high conversion rate of monomer and low gel rate were achieved. The weight ratio of core monomer to shell monomer was approximately 1.35. It is found that many factors such as emulsifiers, initiators, reaction temperature, pH value and polymerization technology have influences on the permormance of styrene-acrylate latex. The prepared latex was characterized by TEM and FTIR. The obtained latex with T of 20.57 ℃, MFT or5.0 ℃, and good stability, had good stability of film forming.

Synthesis of Polyacrylate/Polysiloxane Copolymer and Its Damping Performance

The copolymer of polyacrylate/polysiloxane for vibration damping materials was synthesized through emulsion polymerization. The effects of the amount of methyl methacrylate (MMA), polysiloxane containing vinyl, initiator and emulsifier on the conversion, stability of polyacrylate/ polysiloxane emulsion were discussed when the emulsion was prepared by pre-emulsifying half continuous method. The graft copolymer has good vibration damping performance. The widest glass transition region of the copolymer spans 100℃, and the highest value of tand reached 2.0. The glass transition of the samples was examined by dynamic mechanical analysis (DMA). The vibration damping performance of the graft copolymer was affected by the amount of poly-vinyl dimethylsiloxane (PVMS).

STUDIES ON HIGH SOLID CONTENT AND STABLE EMULSIFIER—FREE EMULSION POLYMERIZATION

In this article, AHPS (3 - allyloxy- 2 -hydrory- 1 -Propanesulfonate salt) wassynthesized to use in emulsifier-Ne emulsion polymerization of BA/BMa/MMA systemfor high solid content latexes. Storage stability klow behavior of the latexes,morphology of the obtained latex particles, dynamic viscoelastic behavior, tensilestrength and water resistance properties of the resulted copolymers were investigated.The experimental results show that with the addition of AHPS, stability of the emulsionis greatly improved that there appears no apparent precipitation dunring thepolymerization and storage at room temperature for 6 months and at -10℃ for fourmonths. Flow of the latexes follows the Bingham body laws, diameter of the latexparticles is about 0.6μn, of which is larger than that of by conventional emulsionpolymerization(0.12μm). In addition, not only water resistance of the copolymersobtained by emulsifier-free emulsion polymerization is greatly improved, but alsotensile strength is obviously enhanced.

水乳型自消光丙烯酸酯共聚物涂层的制备

以苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)为主单体,选择同时带长亲水链段和长疏水链段的二十二烷基醇聚氧乙烯醚-25甲基丙烯酸酯(BEM)为功能单体,连同BEM混合液中含有的甲基丙烯酸(MAA)通过乳液共聚制备了丙烯酸酯共聚物乳液,并以此乳液制备了涂层。在BEM用量为15.0%(以3种主单体St、BA和MMA总质量为基准,下同)的条件下,考察了3种乳化剂复配比例、缓冲剂(Na HCO_(3))加入方式对聚合稳定性、单体转化率的影响;在固定乳化剂复配比例、Na HCO_(3)全部随引发剂溶液同时加入的条件下,考察了BEM用量(0、5.0%、10.0%、15.0%、20.0%)对涂层光泽度和透光率的影响。采用FTIR、SEM、AFM表征了涂层的结构组成和表面形貌。结果表明,利用乳化剂与功能单体BEM长烷基链之间的疏水相互作用,通过复配乳化剂及随引发剂共同滴加缓冲剂Na HCO_(3)的方式,可提高聚合稳定性(絮凝率为0.38%)和单体转化率(≥98%)。利用长链烷基自迁移构建粗糙表面可提高涂层自消光性能,在BEM用量为20.0%时可保持高透光率(≥89%)和低光泽度(35.4%),实现了涂层消光性能和透光性能的统一。

水性环氧乳液/海泡石复合改性苯丙乳液涂层粘结性能研究

采用物理共混法制备水性环氧乳液/海泡石复合改性苯丙乳液涂层,探讨了苯丙-水性环氧乳液配比,三乙醇胺、填料及乳化沥青掺量对涂层粘结强度的影响,同时考察了复合涂层的抗渗性和耐高低温性。结果表明,当苯丙乳液与水性环氧乳液的有效质量比为1∶2,三乙醇胺、海泡石和乳化沥青掺量分别为2%、3%、5%时,复合涂层粘结强度为3.54MPa,与钢板间具有较好的相容性,且不透水性和耐高低温性优良。

水性饰面型防火涂料的制备及其耐火性能研究

[目的]配方对防火涂料的性能有很大影响。[方法]以苯丙乳液和硅溶胶作为基料,聚磷酸铵、季戊四醇和三聚氰胺作为阻燃体系,二氧化钛作为颜填料,六偏磷酸钠作为分散剂,磷酸三丁酯作为消泡剂,羧甲基纤维素作为增稠剂,研制了一种适用于钢结构的水性饰面型复合膨胀防火涂料。利用模拟大板燃烧试验考察了各组分的质量分数对涂料性能的影响,并采用扫描电镜(SEM)对防火涂层燃烧后的微观结构进行表征。[结果]最佳配方为:苯丙乳液20.0%,硅溶胶4.0%,聚磷酸铵27.0%,季戊四醇22.0%,三聚氰胺21.0%,颜填料4.0%,助剂2.0%。此时涂料的耐燃时间长达57 min,燃烧后形成的炭层致密。[结论]该涂料具有良好的防火阻燃效果。