自交联丙烯酸酯类反应性微凝胶乳液的聚合稳定性

采用半连续种子乳液聚合方法合成了自交联丙烯酸酯类反应性微凝胶乳液,研究了聚合工艺条件对聚合反应稳定性的影响。结果表明,当增大乳化剂SDS/OP-10的用量或加快预乳化单体的滴加速度时,聚合反应稳定性增加;随着引发剂过硫酸钾(KPS)、交联剂三羟甲基丙烷三丙烯酸酯(TMPTMA)和单体用量的增加,微凝胶颗粒分子间的交联反应增强,聚合反应稳定性下降。加入功能性单体甲基丙烯酸(MAA)和丙烯酸(AA)都能使聚合反应的稳定性增强,随着MAA用量的增加,聚合反应稳定性呈先增强后下降的趋势。当所加入的SDS/OP-10质量分数为3%~4%、KPS为0.4%~0.6%、TMPTMA为1%~3%、MAA不超过3%及单体为30%~40%,预乳化单体滴加速率为20~30 mL/h时,聚合过程的稳定性最好。由傅里叶变换红外光谱分析可知,通过优化聚合条件,得到了含有官能性环氧基和羧基的丙烯酸酯类反应性微凝胶乳液。     

TMPTMA交联改性聚丙烯酸酯乳液的合成与性能

以三羟甲基丙烷三甲基丙烯酸酯（ TMPTMA ）为内交联单体,苯乙烯（ St ）、甲基丙烯酸甲酯（ MMA）、丙烯酸丁酯（ BA）和甲基丙烯酸（ MAA）为共聚单体,采用半连续核壳乳液聚合工艺合成了自交联聚丙烯酸酯乳液（ T-PAE）。考查了TMPTMA添加量与添加方式对乳液聚合稳定性以及涂膜性能的影响。研究发现：随着TMPTMA含量的增加,T-PAE乳液聚合的稳定性降低,聚合凝胶率增大,乳胶粒的平均粒径下降；涂膜的耐介质性能和交联密度相应提高,合适的TMPTMA加入量为总单体质量的0．5%~1．0%。     

木器底漆用双重自交联丙烯酸酯乳液的制备研究

以甲基丙烯酸甲酯(MMA)和丙烯酸丁酯(BA)为主单体,甲基丙烯酸(MAA)和γ-甲基丙烯酰氧基丙基三甲氧基硅烷(A-174)为功能单体,采用反应型乳化剂NRS-10,通过预乳化半连续乳液聚合工艺合成了自交联丙烯酸酯乳液,并通过添加锌铵交联剂,合成了性能优异的木器底漆用自交联丙烯酸酯乳液。主要考察了乳液Tg,MAA、过硫酸铵(APS)、NRS-10、A-174和锌铵交联剂用量对乳液及其涂膜性能的影响,通过实验得出:当乳液设计Tg为40℃,MAA用量为8%(以单体的总质量计,下同),APS用量为0.3%,NRS-10用量为2.5%,A-174用量为2%,且n(—COO-)∶n(Zn2+)为8∶1时,所制备的自交联丙烯酸酯乳液配制成木器底漆,涂膜具有硬度高、易打磨、耐水性优异等特点。     

国内期刊荟萃

聚苯胺防腐蚀涂料的研制及其性能;室外用超薄钢结构防火涂料的研制;适用于轨道交通轻量化材料防腐的新型颜料;热固型含氟丙烯酸酯树脂的制备;自交联反应性丙烯酸酯类微凝胶乳液及其涂膜的性能……     

水性木器涂料用自交联型丙烯酸酯乳液的制备与性能研究

采用半连续乳液聚合法合成了一种自交联型具有核壳结构的丙烯酸酯乳液,确定了交联单体MAA、DAAM和有机硅单体用量分别为单体总量3%、3%和1%(均为质量分数)时,乳液的综合性能更好,其固含量为50%,黏度为315m Pa·s,粒径为93 nm。该乳液可用于配制水性木器漆底漆和面漆,VOC含量低,快干,涂膜具有较好的丰满度、打磨性和透明度等性能,施工方便,喷涂一底一面即可获得很好的施工性能,缩短施工时间。     

国内期刊荟萃

快速固化的丙烯酸酯微凝胶乳液胡勇辰等. 上海涂料, 2001,(2)：8采用丙烯酸酯类单体合成具有反应性微凝胶的核/壳型胶乳,再通过氨基树脂高温快速固化。讨论了乳化剂组成、核内交联剂的种类含量、壳层单体组成及固化条件等因素对丙烯酸酯微凝胶乳液的稳定性及涂膜性能的影响。试验结果证实,合成具有微凝胶的核、壳型胶乳,有利于快速固化,有利于乳液的稳定性,有利于提高涂膜耐酸、碱性;乳液的钙离子稳定性和冻融稳定性可以通过改变壳层St/BA值来进行调节;本实验体系具有优异的附着力。脂肪族水性聚氨酯涂料的研制许戈文. 涂料工业, …     

单组分室温自交联聚氨酯丙烯酸酯乳液的合成及性能

以含酮基的双键封端的PUA-kt功能单体与甲基丙烯酸甲酯(MMA)、丙烯酸乙酯(EA)等单体共聚合成了聚氨酯丙烯酸酯乳液,再加入一定量己二酸二酰肼,即得室温自交联聚氨酯丙烯酸酯乳液。对聚氨酯丙烯酸酯的合成工艺及性能进行研究,讨论了乳化剂用量对乳液黏度及凝胶率的影响,PUA-kt对乳液黏度及涂膜交联度的影响,ADH用量对涂膜交联度的影响,并用FTIR、TEM、TGA对聚合物进行表征。结果表明,所合成的乳液固含量35%~37%,凝胶率1%以下,涂膜交联度达到82.5%,附着力0级,柔韧性1 mm。     

微凝胶型丙烯酸酯乳液粘度的控制

合成具有反应性微凝胶结构的核／壳型热固性丙烯酸酯乳液。讨论了羟基含量、有机胺中和剂类型、中和度及固含量等因素对乳液粘度及涂膜性能的影响。     

金属防腐漆用双重自交联丙烯酸乳液的制备及其性能研究

以甲基丙烯酸甲酯(MMA)和丙烯酸2-乙基乙酯(2-EHA)为主单体,甲基丙烯酸(MAA)、乙烯基三乙氧基硅烷(A-151)、双丙酮丙烯酰胺(DAAM)和己二酸二酰肼(ADH)的酰肼交联体系以及丙烯酸磷酸酯(PAM-100)为功能单体,采用反应型乳化剂SE-10N,通过预乳化乳液聚合工艺合成了金属防腐漆用双重自交联丙烯酸酯乳液。考察了乳液Tg、MAA、SE-10N、A-151、DAAM/ADH和PAM-100对乳液及其金属防腐漆涂膜的影响。结果表明:当乳液设计Tg为30℃、MAA用量为单体总量的3%、反应型乳化剂SE-10N用量为单体总量的2.5%、A-151用量为单体总量的2%、DAAM用量为单体总量的2%、PAM-100用量为单体总量的3%时,所制备的自交联丙烯酸酯乳液配制成的金属防腐涂料,具有附着力好、耐盐水、耐酸碱、耐盐雾等特点。     

导读

彭晨等以含酮基的双键封端的PUA-kt功能单体与甲基丙烯酸甲酯(MMA)、丙烯酸乙酯(EA)等单体共聚合成了聚氨酯丙烯酸酯乳液,再加入一定量己二酸二酰肼,制得室温自交联聚氨酯丙烯酸酯乳液,对聚氨酯丙烯酸酯的合成工艺及性能进行了研究,讨论了乳化剂用量对乳液黏度及凝胶率的影响,PUA-kt对乳液黏度及涂膜交联度的影响,ADH用量对涂膜交联度的影响,并用FTIR、TEM、TGA对聚合物进行     

反应性微凝胶分散液的流变性能

为了在实际应用中更好地利用反应性微凝胶分散液的流变特性,采用自稳定分散聚合的方法合成了带有环氧基或羧基的反应性微凝胶,并研究了其在不同溶剂中的流变性能。结果表明,与相应的线形聚合物相比,当相对分子质量一定时,反应性微凝胶分散液的特性黏度较低,对聚合物相对分子质量依赖性较小;随着反应性微凝胶交联度的增加,特性黏度变小。在二甲苯中,随着反应性微凝胶质量分数的增加,分散液逐渐由牛顿流体转变为非牛顿流体,且随着反应性微凝胶质量分数的增加,假塑性增加。在甲苯、苯乙烯(St)或甲基丙烯酸异冰片酯(IBOMA)稀溶液中,反应性微凝胶的官能团种类对特性黏度的影响较弱,官能团种类对高浓度溶液的流变性能有较大的影响。     

Hybrid hydrogel based on pre-gelatinized starch modified with glycidyl-crosslinked microgel

Hybrid hydrogels based on pre-gelatinized starch were synthesized by inverse emulsion polymerization through modifying the starch with a glycidyl-crosslinked microgel. Glycidyl-crosslinked microgel is a special latex with high ability to impart hydrophilic characteristics to various substrates. Glycidyl-crosslinked microgel latexes with various structures were synthesized, and the effect of latex type on swelling capacity of the hybrid hydrogels based on pre-gelatinized starch was investigated. The highest swelling capacity was achieved for a pre-gelatinized starch modified with a glycidyl-crosslinked microgel latex based on poly(acrylic acid, sodium acrylate, acrylamide, 2-acrylamide-2 methyl propane sulfonic acid) (AA–SA–AM–AMPS). The swelling values of this hybrid hydrogel in distilled water and saline solution were 52.4 and 28.8 g/g, respectively. A key advantage of these hybrid hydrogels is that starch constitutes 64% of their structure. Given the fact that such hybrid hydrogels display low absorbency under load (AUL), they were surface crosslinked using microwave heating instead of conventional heating. Ethylene glycol diglycidyl ether was used as surface crosslinker. The AUL of the surface crosslinked hybrid hydrogels was increased by 85%. The hydrogels were characterized using FTIR, thermogravimetric analysis, scanning electron microscopy, and rheological measurements.     

Effects of microgel content and n‐methylolacrylamide on the properties of microgel composite hydrogels prepared by postcrosslinking method

Acrylamide co 2‐acrylamido‐2‐methylpropane sulfonic acid microgel composite (MC) hydrogels were prepared by heating MC polymer with 50% water content. Crosslinking reaction occurred in the heating process and reactive microgels with hydroxymethyl groups introduced by N‐methylolacrylamide (NMA) were used as postcrosslinkers. Microgel swollen size is influenced by NMA content. Both microgel and its NMA content affect MC hydrogel properties, which relates to the crosslinking chain length and the crosslinking density. The tensile strength of MC hydrogels increases and their elongation decreases as the microgel content increases from 0.1 to 0.5 g. Both the tensile strength and the elongation decrease as the microgel content further increases from 0.5 to 1.1 g. The MC hydrogel tensile strength increases and the elongation decreases as the NMA content of microgels increases from 5.0 to 14.8%. However, they both decrease when the NMA content of microgels exceeds 14.8%. Although the crosslinking chains υ calculated from tensile stress–strain curves were very high, MC hydrogels were elastic and had the highest tensile strength of 127 kPa and considerably moderate elongation of 427%. Their excellent mechanical properties attributed to their unique structure crosslinked by microgel particles. POLYM. COMPOS., 2012. © 2011 Society of Plastics Engineers     

反应性微凝胶的制备及其在水性涂料中的应用

采用三缩丙二醇二丙烯酸酯作为交联单体,与不饱和聚酯和/或乙烯系不饱和单体乳液聚合,合成了反应性微凝胶乳液。讨论了聚酯中和度、乳化剂、乳化工艺和聚酯用量对微凝胶性能的影响。举例说明反应性微凝胶在水性金属闪光底色漆、本色面漆和中涂漆中的应用,为解决水性涂料的水敏感性和流挂提供新的技术途径。     

Toughening of epoxy-polyamide adhesives with rubbery reactive microgels

An elastomeric microgel with reactive carboxyl groups was prepared by emulsion copolymerization of an unsaturated polyester with 2-ethylhexyl acrylate. An epoxy resin was grafted onto the microgel particles through the addition of the carboxyl group to the epoxy group. The blend of the microgel and the epoxy resin was very stable, the microgel remained as discrete microsphere in the cured resin. The incorporation of the microgel did not cause a significant effect on the network structure of the matrix resin, while the toughness and the adhesive strength of the epoxy-polyamide resins were improved tremendously.     

Synthesis and characterization of fluorine-containing poly-styrene-acrylate latex with core–shell structure using a reactive surfactant

Fluorine-containing poly-styrene-acrylate (PSA) latex with core–shell structure was successfully synthesized by seeded semicontinuous emulsion polymerization using fluorine monomer Actyflon-G₀₄ and reactive emulsifier DNS-86. The chemical composition, morphology of latex, and surface composition of the latex film were characterized by Fourier transform infrared spectra, transmission electron microscopy, and X-ray photoelectron spectroscopy, respectively. The stability properties of latex were tested by Ca²⁺, centrifugal and mechanical stability tests, and the latex film was studied by water contact angle, water absorption ratio, and thermo-gravimetric analysis. The results show that fluorine-containing PSA latex particles with crosslinked core and crosslinked shell structure have excellent stability properties, and the film of latex has excellent water repellency, thermal stability, and chemical resistance properties when the amount of fluorine monomer was only 8.0 wt%.     

Preparation and Properties of Siloxane-Modified Styrene-Acrylate Latex Particles with Core-Shell Structure

Siloxane-modified styrene-acrylate latex particles with core-shell structure were prepared by two-stage semicontinuous emulsion polymerization using a reactive surfactant. Effects of catalyst dosage, weight ratio of γ-methacryloxypropyltrimethoxysilane (MAPS) to hydroxyl silicone oil (HSO) and siloxane content on the grafting degree of siloxane were studied. The chemical components of the copolymer were characterized by Fourier transform infrared spectra. The micromorphology of latex particles was observed by transmission electron microscopy. The stability properties of emulsion were tested by Ca²⁺, centrifugal, and mechanical stability test. The latex film was studied by water contact angle, water absorption ratio and thermal gravimetric analysis. The results show that siloxane-modified styrene-acrylate latex with core-shell structure can be synthesized using reactive surfactant and the prepared emulsion presents excellent stability. By using hydroxyl silicone oil (HSO) to react with silane coupling agent MAPS during emulsion polymerization, HSO can be located in the side chain of the polymer and endow the latex film with excellent stabilities.     

Non-isothermal crystallization kinetics of reactive microgel/nylon 6 blends☆

The non-isothermal crystal ization kinetics of reactive microgel/nylon 6 blends was investigated by differential scanning calorimetry (DSC). The Mo equation was employed to analyze the non-isothermal crystallization data. The crystallization activation energies were also evaluated by the Kissinger method. The results show that the crystallization onset temperature (Tonset) and crystallization peak temperature (Tp) decrease with the increase of the content of reactive microgel, whileΔT (Tonset–Tp), the crystallization half-time (t1/2) and the crystal ization enthalpy (ΔHc) increase. The required cooling rates of blends are higher than that of neat nylon 6 in order to achieve the same relative crystallinity in a unit of time. The crystallization activation energies of the reactive microgel/nylon 6 blends are greater than those of the neat nylon 6. When the content of reactive microgel is 30%, the relative crystallinity (Xt) reaches the maximum.     

反应性微凝胶的制备与应用

聚合物微凝胶是分子内交联并具有轻度网络结构的高分子微粒，通过聚合反应和后处理，可在微凝胶中引入羧基、羟基、磺酸基和氨基等反应性基团成为反应性微凝胶。反应性微凝胶具有良好的施工性能、涂膜性能及耐久性能，主要用于涂料或对涂料进行改性。主要介绍了反应性微凝胶的性能、合成方法及应用。     

Online Particle Size Measurement in Microgel Particle Suspensions: Principles and Data Analysis

If a gelled system is subjected to shearing or the concentration of reactive components is low, microgel particles are formed. Since labile microgel particles with high water capacities can often be found in food systems, and as they are important for the textural properties, particle size measurement is relevant for fundamental research and control of industrial processes. A chord length measurement system was tested for online particle sizing.