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.

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.

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.

Modification of Natural Rubber Latex by Graft Copolymerization of 2-Ethylhexyl Acrylate and Methacrylic Acid

Natural rubber(NR)grafted with 2-ethylhexyl acrylate(2-EHA)and methacrylic acid(MAA,collectively NR-g-PEHA/MAA)was synthesized by emulsion polymerization.Tetraethylenepentamine and cumene hydroperoxide were used as redox initiators.The successful grafting of 2-EHA and MAA onto NR was confirmed by Fourier transform infrared spectroscopy.The morphology of the NR latex particles was observed by transmission electron microscopy.The effects of reaction temperature,initiator dosage,feeding mode,and hard monomer content on the mechanical properties of the modified NR film were investigated.Grafted polymer chains were unevenly wrapped on the outside of NR particles,and smaller particles were more easily grafted.Crosslinking was characterized using a toluene swelling method.Thermal stability and glass transition temperature were examined by differential scanning calorimetry and thermogravimetric analysis.The results showed that the thermal stability of NR-g-PEHA/MAA had been improved,and the glass transition temperature(Tg)was unchanged.

PREPARATION AND PROPERTIES OF SILICONE-ACRYLATE COPOLYMER LATEX

Silicone-acrylate copolymer latex was prepared through three different polymerization processes, i.e., the batch process, preemulsified monomer addition and the monomer addition process. The results revealed that the monomer addition process is a desirable approach to produce narrow particle size distribution latex with higher polymerization conversion and less amount of coagulum. The effect of silicone content on the glossiness and water absorption of latex film was investigated and the results showed that the glossiness of latex film is improved up to a silicone content of 10% of total monomers, but becomes impaired thereafter, whereas water absorption is reduced accordingly.

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.

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.

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.

接枝型天然橡胶基吸水膨胀橡胶的制备及吸水膨胀性能

以脱蛋白天然橡胶(DPNR)胶乳作为改性橡胶的基材,在氧化还原引发体系作用下,基于橡胶大分子链中烯丙基与乙烯基单体的自由基乳液接枝共聚反应实现丙烯酸(AA)在DPNR链上的接枝共聚,从而制备了一种亲水性AA接枝改性DPNR共聚物(DPNR-g-PAA),通过傅里叶变换红外光谱、核磁共振氢谱、扫描电子显微镜和称重法表征了DPNR-g-PAA的分子结构、断面形貌和吸水膨胀性能。结果表明,DPNR-g-PAA作为吸水膨胀橡胶,其薄膜吸水率可达85.06%,DPNR的表面透湿性显著提高;与传统物理共混或溶液接枝共聚反应制备吸水膨胀橡胶工艺相比,由自由基乳液接枝共聚制得的DPNR-g-PAA具有一定的优势。

没食子酸酯/改性苯丙防腐转锈乳胶的制备及性能研究

为提升乳胶的相容性及防腐性能,以没食子酸(GA)与乙二醇丁醚(BE)为原料合成没食子酸酯(GA-BE)作为转锈剂,采用预乳化-半连续种子乳液聚合法合成有机硅改性苯丙乳胶(SALSi)作为成膜物,制备没食子酸酯/改性苯丙防腐转锈乳胶(GA-BE/SAL-Si)。采用稳定性分析仪测试乳胶的稳定性,采用中性盐雾测试、盐水浸泡测试和电化学分析探究其防腐性,采用X射线衍射(XRD)、X射线光电子能谱(XPS)、扫描电镜(SEM)和能谱(EDS)分析探讨锈蚀转化前后基体表面形貌及转锈机理。结果表明:制备的GA-BE/SAL-Si具有较好的稳定性;在3.5%NaCl溶液浸泡下,覆涂GA-BE/SAL-Si试样的自腐蚀电流密度相较于锈蚀钢降低了2个数量级,相较于覆涂GA/SAL-Si试样降低了1个数量级,当GA-BE添加量为2.0%时,防腐效果最佳;经过168 h的中性盐雾测试及盐水测试后,对比GA/SAL-Si及GA-BE/SAL涂膜,GA-BE/SAL-Si涂膜表现出更佳的防腐性能;GA-BE结构中的酚羟基可与锈蚀产物发生螯合反应,生成新的Fe—O—C配位键,达到转锈的作用,配合SAL-Si,使涂膜具有良好的防腐和转锈性能。

无氟拒水剂成膜表面形貌及其拒水性能研究

为考察无氟拒水乳液的成膜形貌对拒水性能的影响,将细乳液聚合得到的聚丙烯酸十八酯-丙烯酸丁酯[P(SA-BA)]胶乳分别与四种粒径的聚丙烯酸十八酯/γ-甲基丙烯酰氧基丙基三甲氧基硅烷[P(SA-A174)]胶乳按比例共混后,采用涂覆和浸轧两种工艺整理玻璃片和面料,以SEM和AFM考察了整理得到的两种基材表面形貌,并考察了对拒水性的影响。结果表明:P(SA-BA)和P(SA-A174)分别具有成膜和保型能力,二者复合而成的胶乳可形成具有纳米“指突”形貌的拒水膜,使整理基材的拒水性能明显提升。随着P (SA-A174)粒径的增大和用量的提高,涂层整理膜的“指突”高度和面密度同时增加,而浸轧整理时,仅“指突”高度增加,面密度和拒水性能变化不大。之后,通过降低浸轧液pH值,胶乳对织物亲和力以及吸附效率增强,浸轧整理织物拒水性能明显提升。

一种水型环保装饰用改性胶粘剂制备及应用性能

为研究绿色环保型的胶粘剂,采用丙烯酸酯乳液(AEL)对复合氯丁胶乳(CRL)进行改性,制备一种环保型水性胶粘剂,并对其性能进行研究。结果表明,AEL和CRL的最佳配比为40∶60,此时,胶粘剂热稳定性良好,断裂拉伸强度为4.87 MPa,断裂拉伸率为524%,在聚氯乙烯(PVC)人造皮革和非织造布上的T型剥离力均达到最大,分别是1.68 MPa、1.63 MPa;在胶粘剂中应添加分子量较大的AEL,可以提高拉伸性能和粘接性能;加入无机纳米材料二氧化硅,可以提高胶粘剂黏度和耐热性。该胶粘剂具备较好的拉伸性能、粘接性能和热稳定性,且绿色环保,可以用于建筑家具装饰。

基于聚碳酸酯高耐性塑料涂料用丙烯酸乳胶的制备与研究

为克服水性涂料在聚碳酸酯(PC)塑料上综合性能不佳的问题,以甲基丙烯酸甲酯(MMA)、苯乙烯(St)、丙烯酸丁酯(BA)为主单体,衣康酸为功能单体,引入长链烷基单体甲基丙烯酸月桂酯(LMA),以及乙酰乙酸基甲基丙烯酸乙酯(AAEM)/聚醚胺交联体系,制备了一种自交联丙烯酸乳胶,研究了不同功能单体、衣康酸、LMA和AAEM/聚醚胺对乳胶及涂膜性能的影响。结果表明:衣康酸用量为3.0%(以单体总质量计,下同)、LMA用量为4.5%、AAEM用量为9.0%、AAEM与聚醚胺物质的量比为2∶1时,制备的单组分水性丙烯酸涂料在PC塑料上具有优异的附着力、耐乙醇擦拭性和耐蒸煮性。

杂化羟基丙烯酸乳胶的制备及其在水性木器涂料中的应用

采用自制水性羟基丙烯酸二级分散体为大分子乳化剂,以苯乙烯、丙烯酸异辛酯、甲基丙烯酸甲酯、甲基丙烯酸羟乙酯、双丙酮丙烯酰胺为共聚单体,制备了用于水性木器涂料的自交联型杂化羟基丙烯酸乳胶,并对其光泽、耐水性、干燥时间、打磨性、适用期进行了分析。结果表明:当自制水性羟基丙烯酸二级分散体的质量分数为13.2%,杂化乳胶的羟基含量为1.5%,双丙酮丙烯酰胺(DAAM)占杂化乳胶体系固体质量的2%时,所制备的水性木器涂料具有光泽高、装饰性好、干燥速度快、打磨性好、活化期长、耐水性好等优点。

建筑外墙抗紫外罩面清漆的研制

开发一款具有耐老化性能的罩面清漆,不仅可以起到屏蔽紫外线的功效,而且方便施工,具有极佳的便捷性与适用性。实验结果表明,实验开发的罩面清漆具有优异的耐老化性能,涂层整体抗老化性能的明显提升,紫外吸收光谱表明,UV-7751W相较于DW-123(N)在紫外波段有更宽泛的响应区间,表现出更良好的抗紫外老化性能,且复配紫外光吸收剂性能更优,其他基础涂膜性能如耐沾污性(<10%)和耐洗刷性(>10000次)远超标准,这对于长久地保持建筑物清洁自然,延长建筑物的翻新周期,节约自然资源至关重要,符合新时代的发展要求。

DMS AND ^(13)C NMR STUDIES ON THE COMPATIBILITY AND DYNAMICS OF LATEX BIDIRECTIONAL IPNS AND LATEX IPN OF PVAc/PBA

The compatibility and dynamics of latex bidirectional/nterpenetrating polymer networks (LBIPNs) and latex IPN(LIPN) of poly(vinyl acetate)(PVAc) and poly (butyl acrylate )(PBA) are investigated by means of dynamic mechanical spectroscopy (DMS) and nuclear magnetic resonance (NMR) techniques. The results of DMS show that the compatibility of the LBIPNs is much better than that of the corresponding LIPN and depends to, a large extent on the distribution of PVAc both in the core and in the shell. The results of NMR measurements indicate that the rotational correlation times of the side- groups of PBA in the LBIPN are longer than those in the LIPN. The relation between the ^(13)C linewidths of PBA and temperature is also discussed.

HIGH SOLIDS-CONTENT NANOSIZE POLYMER LATEXES MADE BY A MODIFIED EMULSION COPOLYMERIZATION

Polymer nanoparticles were prepared in the methyl methacrylate (MMA)/buty lmethacrylate (BA) emulsion copolymerization process by a modified microemulsion copolymerization method. 2-Hydroxyethyl methacrylate(HEMA), acrylate (AA) and methyl acrylate (MAA) were used as reactive cosurfactants. With this process high polymer: surfactant weight ratios (40:1 or greater),relatively concentrated (~30wt. %) latexes and small (~60nm) particle diameters were obtained.Properties of the latexes were characterized by TEM, DSC, dynamic light scattering, and IR spectroscopy.

聚丙烯酸十八酯防水乳液的成膜能力调控及其对防水性能的影响

针对聚丙烯酸酯型防水剂(PA)织物适用面窄的问题,探讨了PA成膜能力与其防水性能的关系。采用细乳液聚合技术,并通过调控共聚组成、添加链转移剂和助溶剂的方法,提升了PA胶乳的成膜能力,并将其用于防水整理。结果表明,成膜能力高的防水剂更易在纤维表面铺展,形成均匀涂膜,不仅赋予面料更高的防水性能,而且防水性能更耐久,对面料的适用性更广。

GMA改性水性丙烯酸酯乳液对PET织物表面性能的影响

针对水性丙烯酸酯乳液耐酸性差以及PET织物表面疏水的问题,以丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)和丙烯酸(AA)为单体,设计引入一种特殊的功能单体甲基丙烯酸缩水甘油酯(GMA),采用预乳化工艺和半连续种子乳液聚合法合成了耐酸的水性丙烯酸酯乳液。利用红外光谱、热重分析仪、流变仪等分析了GMA的改性效果,结果证明引入GMA的改性丙烯酸酯乳液成功合成,且在GMA质量分数为2%时性能最佳,乳液平均粒径为141 nm,比改性前减小了21%,剪切速率为3000 s^(-1)时的剪切黏度为182.6 mPa·s,比改性前降低了27%。再用十二烷基辛基酚聚氧乙烯醚(OP-10)复合GMA改性乳液对PET织物表面进行涂覆热处理,对PET织物进行接触角和浸酸失重测试的结果表明,其表面接触角由处理前的109.7°减小至12.6°,减小了88.5%,70℃浸酸7 d的浸酸失重由处理前的质量分数2.39%减小至0.26%,降低了89.1%,PET织物表面呈现良好的亲水性且表面耐酸性增强效果显著。

水性氯丁-丙烯酸酯复合乳液胶黏剂性能的影响因素

采用水性氯丁与丙烯酸酯共混的方式,制备得到了速粘自干水性胶黏剂。详细考察了乳液的结晶性、玻璃化转变温度(T_(g))、丙烯酸酯乳液(AEL)/氯丁乳液(CRL)的配比对胶黏剂力学性能的影响。通过拉力测试、热重分析(TG)、耐热测试、T型剥离力测试等分析表明:当C84/C2694=8∶2、SL-390/C2694=8∶2、丙烯酸酯乳液的T_(g)在-50~-60℃之间、且AEL/CRL的质量比为40∶60时,乳液胶黏剂的综合性能最佳。