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%。     

核壳结构的羧基型丙烯酸酯乳液的制备与表征

以甲基丙烯酸甲酯（MMA）、丙烯酸异辛酯（ 2-EHA）为单体,甲基丙烯酸（MAA）为羧基功能单体,采用半连续种子乳液聚合工艺,制备了核壳结构的羧基型丙烯酸酯乳液,研究了 MAA用量对乳液的粒径、流变特性及胶膜亲水性的影响,采用 FT-IR、TEM、DSC对乳胶粒的结构和形貌进行了表征。结果表明：随着 MAA用量的增加,乳胶粒的粒径呈现先减小后增大的趋势, MAA质量分数为 6%时,粒径为 186 nm;MAA用量超过 4%时,乳液黏度显著提高; MAA用量的增加,胶膜的接触角降低,亲水性增加。     

聚烯烃塑料用胶粘剂SBS／MMA／BA／MAA的合成与性能研究

以甲基丙烯酸（MAA）为功能单体,与SBS和甲基丙烯酸甲酯（MMA）、丙烯酸丁酯（BA）进行四元接枝共聚,合成了聚烯烃塑料用胶粘剂,探讨了不同溶剂、MMA／BA配比、MAA和BPO用量以及固化时间对粘接性能的影响,并对该四元接枝胶的性能与三元胶和SBS／MMA／BA／AA四元接枝胶进行了比较。结果发现：四元接枝胶性能优于三元胶,特别是与异氰酸酯配合时,剪切强度、固化速度明显提高,四元胶的优化配方是120＃汽油：甲苯：乙酸乙酯为8：1：1,MMA：BA配比3：1,MAA加入量7份,BPO用量1．5－2份（以100份SBS计）。     

自沉积涂料用环氧丙烯酸酯共聚乳胶的合成

以苯乙烯(St)、丙烯酸丁酯(BA)、甲基丙烯酸甲酯(MMA)、丙烯腈(AN)、甲基丙烯酸(MAA)、甲基丙烯酸羟乙酯(HEMA)及环氧EPON 828等为主要原料,采用乳液共聚法合成了可用于自沉积涂料的环氧丙烯酸酯共聚乳胶。采用红外光谱仪、核磁共振仪、示差热分析仪、扫描电镜研究了其结构和性能。结果表明:丙烯酸酯单体与环氧树脂发生了良好的共聚反应。当乳化剂中十二烷基硫酸钠、壬基酚聚氧乙烯醚和乙烯基磺酸钠的质量比为2∶1∶2,功能单体MAA、乳化剂和环氧EPON 828的用量分别为总单体质量的3%,3.8%和30%时,聚合过程稳定性和乳液储存稳定性最好,聚合物胶乳的性能最佳。     

正交优化水性丙烯酸树脂的合成及性能研究

合成了碱溶性聚丙烯酸乙酯/丙烯酸丁酯/甲基丙烯酸[P(EA/BA/MAA)]无规共聚物,研究其对单体甲基丙烯酸甲酯(MMA)和丙烯酸乙酯(EA)的乳化稳定能力.以合成的[P(EA/BA/MAA)]作为高分子乳化剂,进行甲基丙烯酸甲酯/丙烯酸乙酯/甲基丙烯酸/甲基丙烯酸-β-羟乙酯[P(MMA/EA/MAA/HEMA)]乳液聚合反应;并通过正交试验对乳液的聚合参数进行优化,得到了最佳合成条件;在此条件下合成的乳液稳定性好、吸水性低,转化率高.采用FT-IR、TEM对聚合物乳液的结构进行了表征;TEM图片证实,乳胶粒子呈明显的核/壳结构,平均粒径80 nm.     

不同交联单体对水性丙烯酸防腐乳胶性能的影响

从乳胶稳定性、涂膜耐水性、涂膜耐盐雾性能等方面研究了N–羟甲基丙烯酰胺（N-MA）、甲基丙烯酸（MAA）、硅烷偶联剂以及磷酸酯功能单体4种不同交联单体对丙烯酸乳胶的性能影响。数据表明,适量加入N-MA会提高乳胶的稳定性,过多加入则会导致乳胶凝胶量增多,同时引起乳胶膜耐水性下降;MAA质量分数为2.0%时,对提高聚合物交联密度和涂膜硬度有作用;硅烷偶联剂质量分数为0.3%时,且采用后加入方式有利于提高乳胶稳定性;磷酸酯功能单体对改善涂膜耐盐雾性能效果显著。     

低温无甲醛涂料印花粘合剂的研制

配制了一种低温交联型印花粘合剂。采用预交联方法，粘合剂合成过程中引进交联，软硬单体比为3.5:1，当达到5：1时非常柔软，在未加共聚单体A时，乳胶膜的Tg=-27.8℃，加入8%共聚单体后的乳胶膜的Tg=-5.6℃，增加MAA的含量使乳液稳定，印花后织物的鲜艳度提高，超过4%则湿态强度下降，故以3-4%为宜，实验结果表明，这种无甲醛涂料印花粘合剂在低温下应用于织物摩擦牢度达到国家标准。     

高固含量BA/MMA/MAA共聚乳液的合成及性能:单体配比的影响

研究了用不同配比的单体制得的高固含量BA／MMA／MAA共聚物乳液的乳胶粒、乳液的稳定性、粘度及乳胶膜性能。发现：混合单体中MMA用量增加,乳胶粒粒径变大;聚会稳定性变差;MAA用量加大,乳液粘度变大;高固含量BA／MMA／MAA乳液聚合主要是无规聚合;共聚物聚集态为非晶态。     

水性涂料用苯丙树脂的制备及胶膜性能

以甲基丙烯酸(MAA)为亲水单体、甲基丙烯酸羟丙酯(HPMA)为交联单体,与苯乙烯(St)、甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)等通过半连续及转相乳液聚合法,制备了具有核壳结构的水性苯丙水分散体乳液,进一步将乳液制备成苯丙树脂胶膜。探讨了MAA核壳质量比,MAA、St、HPMA等单体用量对水性苯丙树脂水分散体乳液性能及胶膜性能的影响,并利用傅里叶变换红外光谱仪(FTIR)及热失重分析仪(TGA)对苯丙树脂胶膜的结构及热稳定性进行了表征,利用激光粒径散射仪(DLS)及透射电镜(TEM)对苯丙树脂乳液乳胶粒的大小及形貌进行了表征。结果表明:当MAA在核壳中分配质量比为2∶8、MAA用量为7%(以单体总质量为基准,下同)、HPMA用量为10%、St与MMA质量比为3∶1时,得到共聚物乳液的粒径为259.65 nm,黏度为349.1 mPa?s,胶膜耐水时间为90 h,硬度为72.4?,拉伸强度为1.422 MPa,断裂伸长率为59.355%;水性苯丙水分散体附着力为1级。     

水溶性单体类型对BA-MMA-St微皂乳液聚合的影响

通过与水溶性单体、甲基丙烯酸（MAA）、丙烯酸（AA）、N-羟甲基丙烯酰胺（N-MA）、丙烯酰胺（AM）共聚，实现了BA-MMA-St的微皂乳液聚合。考察了水溶性单体（羧酸类单体、非离子水溶性单体）对微皂乳液聚合稳定性和化学稳定性的影响。实验结果表明：为了使水溶性单体键合在乳胶粒表面，实现乳胶粒的稳定化，其亲水性参数I／O应为3～5，水溶性单体还必须具有良好的聚合稳定性及与主单体良好的共聚性。     

丙-叔-醋共聚乳液的研制与应用

通过使用非离子型乳化剂和阴离子型乳化剂组成的复合乳化剂和保护胶体,利用各反应物中丙烯酸酯,叔碳酸乙烯酯憎水性强、抗剪切强度好和较好的内增塑作用的特性,以丙烯酸酯、叔碳酸乙烯酯、醋酸乙烯酯为反应单体进行聚合,采取对混合单体先预乳化后滴加,控制反应过程的方式,制得丙-叔-醋多元共聚乳液,以其为基料,根据乳胶漆的生产需要,加入各种填料和助剂,制成乳胶漆,产品具有良好的耐水、耐酸碱和耐擦洗性,满足优质乳胶漆的应用性能要求。     

VAc/Veova型可再分散性乳胶粉的工艺条件研究

以聚乙烯醇(PVA)为保护胶体、过硫酸铵(APS)为引发剂、醋酸乙烯(VAc)和改性单体(Veova)为主要原料,采用种子乳液聚合法制备VAc/Veova乳液;然后以此为母液,采用喷雾干燥法制备可再分散性乳胶粉。结果表明:当保护胶体选择低聚合度不完全皂化的PVA、采用连续滴加法加入引发剂、采用前混工艺加入抗结块剂、干燥塔进口温度为150～200℃和出口温度为80～90℃时,VAc/Veova型可再分散性乳胶粉的主要应用性能满足JG 149—2003标准,并且接近甚至超过国内外同类产品。     

Postpolymerization of vinyl acetate‐containing latexes

The postpolymerization of vinyl acetate (VAc)‐containing latexes with tert‐butyl hydroperoxide (TBH)/ascorbic acid (AsA) as a redox initiation system was investigated. Volatile organic compounds (VOCs) such as acetone and tert‐butyl alcohol were produced in this process. The influence of the TBH/AsA ratio, initiator concentration, reaction temperature, and feeding time on the reduction of residual VAc and VOC formation during the postpolymerization was investigated. A total reduction of residual VAc monomer was achieved, with the formation of VOCs kept within acceptable limits. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 923–928, 2002     

Empirical Modeling of Butyl Acrylate/Vinyl Acetate/Acrylic Acid Emulsion‐Based Pressure‐Sensitive Adhesives

Summary: Butyl acrylate/vinyl acetate/acrylic acid (BA/VAc/AA) emulsion latexes were produced in a semi‐batch mode. The objective was to generate polymers with properties favoring their application as pressure‐sensitive adhesives. The influence of the individual monomer concentrations on final properties such as glass transition temperature (T_g), peel strength, shear strength and tack was investigated. To obtain the maximum amount of information in a reasonable number of runs, a constrained three‐component mixture design was used to define the experimental conditions. Latexes were coated onto a polyethylene terephthalate carrier and dried. Different empirical models (e.g. linear, quadratic and cubic mixture models) governing the individual properties (i.e. T_g, peel adhesion, shear resistance and tack) were developed and evaluated. In the given experimental region, no single model was found to fit all of the responses (i.e. the final properties). However, in all models the most significant factor affecting the final properties was the AA concentration, followed by the VAc concentration.

Shear strength contour lines over the investigated region.     

Structure and properties of AN/MAA/AM copolymer foam plastics

In this article, acrylonitrile (AN)/methacrylic acid (MAA)/acrylamide (AM) copolymer foam was prepared. DSC, TG and FTIR were adopted to analyze the chemical reactions in AN/MAA/AM copolymer foam, and confirm its molecule structure. SEM was employed to observe its cell structure, and the calculational method of resin distribution was founded basing on dodecahedron cell structural model. At last, its mechanical properties and thermal resistance were tested. The results indicate that cyclization reactions occur between adjacent AN/MAA units and MAA/AM units. Six-member imide rings, residuary MAA and AN units exist in main chains, and imide groups crosslink the chains. AN/MAA/AM copolymer foam has flat and closed cell walls with a high cell wall volume ratio. Cell wall volume ratios with the density of 32 kg/m³, 54 kg/m³ and 75 kg/m³ are 76%, 57% and 50% respectively. Because of rigid molecule structure and ideal cell structure, AN/MAA/AM copolymer foam possesses excellent mechanical properties and thermal resistance. As the densities are 32 kg/m³, 54 kg/m³ and 75 kg/m³, tensile strength are 1.00 MPa, 1.85 MPa and 2.30 MPa, compressive strength are 0.40 MPa, 1.00 MPa and 1.72 MPa, and shear strength are 0.45 MPa, 0.86 MPa and 1.29 MPa respectively. Heat distortion temperature of the copolymer foam is higher than 180 °C.     

粘贴导静电PVC地板的导静电乳液型胶粘剂的研制

用乳液聚合法制备了用于粘贴导静电PVC地板胶粘剂的醋酸乙烯酯-丙烯酸酯乳液,加入水性聚氨酯和增黏树脂提高乳液型胶粘剂的性能,加入导电纤维赋予乳液型胶粘剂导静电性能。研究了影响胶接强度和初粘力的主要因素,结果表明,胶接强度随醋酸乙烯酯、水性聚氨酯和滑石粉加入量增大而增大;初粘性随醋酸乙烯酯加入量的增大而减小。确定了较合适的m(VAc)/m(BA+VAc)=0 5,导静电性能由导电纤维决定,其加入量越大,导静电性能越好。得到的导静电乳液胶粘剂胶接强度达到0 56MPa,导静电能力可达到3 8×103Ω,两项指标均超过国家标准。     

指接材双组分胶粘剂的研制

研制了指接材双组分胶粘剂。研究了丙烯酸用量、引发剂用量和多亚甲基多苯基多异氰酸酯用量对乳液剪切强度的影响,同时还研究了引发剂用量和保温时间与乳液转化率的关系。结果表明:当丙烯酸用量为3％、过硫酸铵为0．5％、保温时间为40min、多亚甲基多苯基多异氰酸酯为14％时,乳液的干／湿态剪切强度分别为11．2MPa和6．3MPa。     

Emulsion copolymerization of vinyl acetate and 2‐ethyl hexyl acrylate using nonionic emulsifiers in loop reactor

Batch emulsion copolymerization of vinyl acetate and 2‐ethyl hexyl acrylate (VAc/2EHA = 90 : 10) was initiated by the thermal initiators ammonium persulfate and potassium persulfate at 70°C in the presence of nonylphenol ethoxylates with varying chain lengths and poly(vinyl alcohol). VAc–2EHA copolymer latexes were synthesized as two different series in a loop reactor. The first series was initiated by ammonium persulfate, and the second series was initiated by potassium persulfate. The influence of the counterions or initiators and chain lengths of a nonionic emulsifier on the properties of VAc–2EHA copolymer latexes were determined by measuring the viscosities, weight‐average molecular weights, number‐average molecular weights, molecular weight distribution, and surface tension of latexes to air. The results for the copolymer latexes indicated that some of their physicochemical properties increased with increasing chain length of the nonionic emulsifier, but some of them followed a different trend for the two initiators. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1380–1384, 2005     

Fourier transform ir studies of the degradation of polyacrylonitrile copolymers—I: Introduction and comparative rates of the degradation of three copolymers below 200°c and under reduced pressure

Polyacrylonitrile (PAN) and copolymers of PAN containing comonomers of vinyl acetate (VAc), methacrylic acid (MAA), acrylamide (AM) and other acrylics are important precursors to the formation of carbon fibers. Fourier transform IR spectroscopy has proved to be an excellent technique with which to study the degradation of these polymers in the initial stages where cyclization of the polymer chain takes place. In this communication we present comparative rate studies of the degradation of three PAN copolymers containing approx. 4 wt% of VAc, MAA and AM respectively. The rate of degradation is observed to be markedly dependent upon the chemical structure of the comonomer.     

Synthesis of a silicone containing allylic monomer and its uses in the waterborne polyurethane/vinyl acetate–acrylic hybrid emulsion copolymers

A new silicone containing allylic monomer, allyl 3-(triethoxysilyl) propyl carbamate (ATESPC), based on (3-isocyanatopropyl) triethoxysilane (ICPTES) and allyl alcohol (AAL) has been synthesized for formulation of waterborne polyurethane (WPU). Then a series of new siliconized WPU, vinyl acetate (VAc)/2-ethylhexylacrylate (2-EHA) and ATESPC hybrid latexes P(VAc-2-EHA)/PU/Si have been successfully synthesized by the emulsion copolymerization in the presence of a WPU dispersion by using potassium persulfate (KPS) as an initiator. The WPU dispersion has been synthesized by a polyaddition reaction of hexamethylene diisocyanate (HMDI), on polypropylene glycol (PPG-1000) and dimethylol propionic acid (DMPA) as chain extender. The NCO chain ends being reacted with water (which act as a further chain extender producing some urea bonds). Films were obtained for different hybrid latexes of various compositions. The resulted monomer characterized by Fourier transformer infrared spectroscopy (FTIR), proton (¹H NMR), and carbon (¹³C NMR) nuclear magnetic resonance spectroscopes, respectively. The copolymers also were characterized by using Fourier transform infrared spectroscopy (FT-IR). Thermal properties of the copolymers were studied by using thermogravimetric analysis (TGA) and dynamic mechanical thermal analysis (DMTA). The morphology of copolymers was investigated by scanning electron microscopy (SEM) and then the effects of silicone concentrations on the water absorption ratio, was examined.