硬段含量对聚酯型水性聚氨酯的影响

以聚已二酸新戊二醇酯二醇(PNA)和异佛尔酮二异氰酸酯(IPDI)为主要原料,二羟甲基丙酸(DMPA)为亲水扩链剂,一缩二乙二醇(DEG)为小分子扩链剂,合成了一系列水性聚氨酯乳液.采用傅里叶红外光谱对水性聚氨酯的结构进行表征,并考察了不同DMPA含量、不同IPDI与PNA配比对乳液粒径及涂膜吸水率、机械力学性能、耐热性的影响.结果表明,提高DMPA含量使乳液粒径逐渐减小,增大异氰酸酯与多元醇物质的量比n(-NCO)/n(-OH)使乳液粒径增加;DMPA含量或n(-NCO)/n(-OH)的提高,均能提高涂膜的拉伸强度,但涂膜的断裂伸长率降低且吸水率增加.热重分析表明n(-NCO)/n(-OH)比例的增加使涂膜的耐热性降低.     

水性双组分涂料用丙烯酸酯乳液的羟值因素

以甲基丙烯酸-β-羟丙酯(HPMA)为羟基单体,采用种子乳液聚合、极性单体分段滴加工艺合成了高羟值(98.8 mgKOH/g)和高固含量(≥45.0%)的丙烯酸酯乳液,配制水性双组分丙烯酸酯聚氨酯涂料(2K-WPU),考查了羟值对聚合稳定性、乳液粒径和涂膜物理化学性能的影响,研究了水性双组分丙烯酸酯聚氨酯涂料合适的-NCO和-OH物质量的比.研究发现:羟值的提高会增加乳液聚合的凝胶率,降低单体的转化率,使乳液聚合稳定性下降,乳液粒径变大,分布变宽;涂膜硬度和交联度随羟值的增大而提高,涂膜光泽和耐介质性能分别在羟值为65.9 mgKOH/g和82.4 mgKOH/g时达到最佳;当n(-NCO)∶n(-OH)为1.5～1.8时,水性双组分丙烯酸酯聚氨酯涂膜的综合性能最佳.傅里叶红外光谱分析表明在涂膜形成过程中-NCO与-OH的固化反应完全需7 d,TGA分析了水性双组分聚氨酯涂膜的耐热性.     

含疏水侧链聚氨酯表面活性剂的制备及其乳液聚合应用研究

以异佛尔酮二异氰酸酯、二羟甲基丙酸和单硬脂酸甘油酯为主要原料,通过改变原料配比制备一系列含疏水侧链聚氨酯表面活性剂。采用FT-IR和~1H NMR对产物的结构进行了表征。以单体质量5%的聚氨酯表面活性剂制备了固含量(质量分数)为35%的聚甲基丙烯酸甲酯-co-聚丙烯酸丁酯乳液,研究了预聚物n(-NCO)/n(-OH)对表面活性和乳液聚合应用的影响。结果表明,当预聚物n(-NCO)/n(-OH)=1.07时,含疏水侧链聚氨酯表面活性剂水溶液具有最低表面张力值33.24 mN/m。该聚氨酯表面活性剂用于制备聚丙烯酸酯乳液可得到核壳结构乳胶粒子,当预聚物n(-NCO)/n(-OH)=1.11时,制备得到的乳胶粒子最小,直径约为75 nm。     

纳米碳酸钙改性水性双组分胶粘剂的合成与性能研究

合成了一种综合性能优良的环境友好型双组分粘合剂,并对其进行性能研究:采用旋转粘度计研究了PVA含量对乳液粘度的影响,并就羟基含量、n(-NCO)/n(-OH)比值(R值)以及纳米碳酸钙的含量等对胶膜的耐水性能和粘接强度的影响进行了研究。研究结果表明:PVA含量为1.5%～2.5%时乳液粘度比较适宜;当R值为1.3、羟基含量为2%～3%及纳米碳酸钙加入量为2%～3%时,胶膜综合性能优异。     

聚氨酯交联改性聚丙烯酸酯压敏胶的研究

采用溶液自由基共聚法合成了含有羟基的(甲基)丙烯酸酯共聚物(PA),采用预聚法合成了端-NCO基聚氨酯(PU)预聚体,然后将PA和PU预聚体混合均匀后制备PUA压敏胶。考察了n(-NCO)∶n(-OH)比例、不同相对分子质量(Mn)的聚丙二醇(PPG)和不同类型的聚醚合成的PU预聚体对PUA压敏胶性能的影响。实验结果表明,改性PUA压敏胶的剥离强度随着PU预聚体用量的增加而逐渐降低,最大降幅为8N/30mm左右,但残胶现象可消除;当n(-NCO)∶n(-OH)=3∶2、m(PA)∶m(PU)=10∶1且PPG的Mn为400时,所制取的PUA压敏胶的持粘性较未改性PA压敏胶提高了267%,但初粘性则有所降低;对Mn均为400的聚乙二醇(PEG)和PPG而言,由PEG400合成的PUA压敏胶比由PPG400合成的PUA压敏胶改性效果更好。     

一种水性聚氨酯地坪涂料的制备及性能影响因素探讨

采用羟基丙烯酸乳液、水性聚氨酯固化剂、无重金属颜填料等原材料,制备了一种双组份水性聚氨酯地坪涂料,重点探讨了n(-NCO)/n(-OH)比例、颜基比及成膜温度对涂膜性能的影响,得到了一种性价比优异的环保型水性聚氨酯地坪涂料。     

双组分水性聚氨酯中涂漆的制备及性能研究

以羟基丙烯酸乳液和水性聚氨酯固化剂为成膜基料体系,配以优选助剂、颜填料和助溶剂等制备了满足车用工艺及性能要求的双组分水性聚氨酯中涂漆.考察了羟基丙烯酸乳液、水性聚氨酯固化剂树脂、n(-NCO)/n(-OH)比例及助溶剂等因素对涂膜外观及性能的影响,经配方优化后,得到了最佳的涂层效果.     

阴离子聚醚型水性聚氨酯的合成及性能研究

采用预聚-封端法合成一种主要用于织物整理的阴离子聚醚型水性聚氨酯.并讨论了DMPA的用量、-NCO/-OH(R值)等时乳液性能的影响.结果表明:DMPA%为6%、R值为3得到的乳液及涂膜性能较好.     

低模量单组份聚氨酯密封胶的研制

以聚醚多元醇、TDI、MDI、增塑剂为原料合成聚氨酯预聚体,添加滑石粉、触变剂、潜固化剂等助剂研制出一种无泡、低模量、高弹性的单组份聚氨酯密封胶,探讨了聚醚多元醇、潜固化剂、气相二氧化硅对密封胶性能的影响。结果表明,该密封胶配方的适宜配比为n(TDI)/n(MDI)=2～2.5、n(-NCO)/n(-OH)=1.7～1.9、潜固化剂含量1.2%～1.5%、气相二氧化硅含量1.5%～2.5%。     

多官能度水性光敏聚氨酯丙烯酸酯的合成及性能研究

用异佛尔酮二异氰酸酯(IPDI)、丙三醇、聚四氢呋喃醚二醇(PTMG)、甲基丙烯酸羟乙酯(DMPA)、季戊四醇三丙烯酸酯(PETA)等原料合成了具有高交联度的多官能度紫外光固化聚氨酯丙烯酸酯(PUA)水乳液。采用国标GB12009.4—89,FT-IR,13C NMR,DMA,AFM等方法对PUA预聚体合成过程和聚合物乳液(涂膜)进行了测试和表征,考察了n(IPDI)∶n(HO—OH)∶n(丙三醇)、DMPA质量分数、pH值等对乳液及涂膜性能的影响。结果表明,随着丙三醇质量分数增大,PUA光固化速率、耐溶剂性、膜硬度提高、吸水率降低;随着DMPA质量分数的增加,PUA涂膜硬度、吸水率增强,乳胶粒径越来越小;随着中和度增大,乳液逐渐由云雾状趋向透明,粘度下降。当n(IPDI)∶n(HO—OH)∶n(丙三醇)=9∶6∶1,w(丙三醇)=2%左右,DMPA质量分数为4.6%,中和度为90%时,乳液储存稳定(30 d),涂膜光固化速率达到7 s,附着力为1,硬度为3 H,耐水性、耐化学品性更佳。     

生物胶乳对纸张施胶性能的影响

合成胶乳表面施胶剂是常用的表面施胶剂,但是近年来合成胶乳的价格不断上升,给企业的成本带来巨大的压力。而生物胶乳作为环保型胶乳,又具备合成胶乳的功能,研究生物胶乳代替部分合成胶乳,有良好的前景。以丁苯胶乳、生物胶乳为原料,从胶乳配比、纳米粒子含量、分散速度、分散转速等方面着手,以抗张强度、平滑度、施胶度、白度为指标,得出了表面施胶液的最佳方案,即丁苯胶乳/生物胶乳为80∶20,纳米碳酸钙含量为8%,分散时间为80 min,分散转速为3 000 r/min。在适宜条件下进行表面施胶,纸张的施胶度可以提高10.74,并且抗张指数可以提高32.2%,平滑度等指标都有明显的改善。     

Cationic latex interaction with pulp fibers. I. Deposition of styrene-butadiene latex having quaternized amino groups

Four experimental latexes of different styrene-butadiene ratios stabilized with quaternized amino groups were employed in deposition studies on unbeaten kraft pulp fibers. The attraction between the oppositely charged latex and fibers facilitates a ready latex deposition in the pH region between the points of zero charge of the latex and of the fibers. The rate of deposition appears to be controlled by latex diffusion and convection up to the fiber surface. The distribution of latex particles deposited on the fiber surface is related to the butadiene content and the latex stability. Polystyrene latex is the most stable and covers the fibers uniformly as individual particles. With increased butadiene content, the coagulation region of the latex is more extended and the tendency to deposit as aggregates is promoted.     

环氧乳液与含氟乳液的拼混研究

运用种子乳液聚合法制备了固含量(固体质量分数)为45%的含氟乳液;运用后乳化法制得了环氧乳液。ATR-FTIR测试表明环氧乳液与含氟乳液进行了有效的拼混。运用KrussK12型动态表面能分析仪测试了含氟涂膜对水和十六烷的接触角,对影响拼混乳液涂膜性能的因素如环氧树脂及其固化剂的比例、氟原子含量、成膜基材材质、成膜温度等进行了探讨研究。结果表明制备的含氟拼混乳液性能良好。     

Impact of functionalised dispersing agents on the mechanical and viscoelastic properties of pigment coating

The effect of poly(acrylic acid) – poly(styrene sulphonic acid) (AA-SSA) and poly(acrylic acid) – poly(2-acrylamido-2-methylpropane sulphonic acid) (AA-AMPS) dispersing agents on the viscoelastic and mechanical properties of precipitated calcium carbonate-latex composites used was investigated. Four different formulations were prepared using carboxylated styrene butadiene (SBR) and styrene-acrylate (SA) latexes. Pore space was characterised using mercury porosimetry. The storage modulus and loss factor were evaluated through dynamic mechanical thermal analysis (DMTA) low frequency single cantilever bending mode. The ultimate tensile strength and the Young modulus were also measured. At low latex contents, storage modulus was found to be higher for SBR latex composites. At high latex content, the SA storage modulus was found to be higher. It is suggested that at lower latex content, the viscoelastic properties are function of physical microstructure, which at low latex is influenced by the latex glass transition temperature (Tg). Softer latex spreads more on the pigment surface providing higher stiffness, since pigments are held together by latex bridges. At higher latex content, the composite stiffness tends to be more dependent on the stiffness of the pure latex. The AA-SSA dispersant creates strong pigment–latex interfacial adhesion in dry composites, which is reflected in high elastic modulus and tensile strength. The AA-AMPS dispersant formulations had greater resistance to water. Due to the compatibility between the AMPS blocks and the SBR latex within the composite, higher storage modulus stability in water saturated composites is measured (at room temperature 56% of the storage modulus is preserved).     

Synthesis and properties of the vinyl silicone oil modified polyacrylate core-shell latex as a binder for pigment printing

Vinyl silicone oil (VSO) modified polyacrylate latex is synthesized by emulsion polymerization. The core-shell structure of the latex particle is observed on transmission electron microscopy. The chemical structure of the copolymer was characterized by infrared spectrum. The glass transition temperatures of core-layer and shell-layer of latex particle are determined by differential scanning calorimetry. The size of particle of the core-shell latex is measured on a nanoscale granularity analyzer. The good softening effect of VSO is proved by the application of the latex as a binder of pigment printing on textiles. The good fastness of the printed fabrics is obtained^, which shows that the synthesized core-shell latex can be used as a binder in pigment printing of textiles.     

油井水泥专用丁苯胶乳的实验评价

针对传统丁苯胶乳在油井水泥浆中适用性能差的问题,采用种子乳液聚合方法合成了一种油井水泥专用丁苯胶乳,并对其进行了微观结构和应用性能评价。该丁苯胶乳物理性能、红外及热失重分析结果表明：该丁苯胶乳乳液稳定性好,高温下分子结构稳定。丁苯胶乳水泥浆的应用性能结果和微观结构分析表明：该丁苯胶乳水泥浆API失水可控制在50 mL内,耐盐性能好,可解决传统胶乳水泥浆稠化实验"鼓包"、"包心"等问题;加有该丁苯胶乳的水泥浆早期强度发展快,胶凝强度过渡时间短;丁苯胶乳能细化水泥浆的孔径结构,提高水泥浆的胶结强度和形变能力,并且其水泥石的柔韧性比原浆水泥石提高了30%;此外,能够满足深井、超深井和气井等复杂井的固井作业要求。     

Multistage latex particle size analysis by disc centrifuge photosedimentometry

Characterization of a heterogeneous latex polymer synthesis requires quantifying the association of successive stage compositions with the previous stage latex seed particles. A new method for performing this analysis is presented for uniform sized latex particles by use of a Joyce Loebl disc centrifuge photosedimentometer. An iterative procedure is employed to solve a problem of unknown particle density when a successive polymerization produces new latex particles. The procedure is applicable regardless of the monomer compositions of the various stages and eliminates problems encountered with electron microscopy of soft deformable latex particles.     

LPNR胶乳和NR胶乳热降解性能的研究

采用热重分析法和导数热重分析法研究低蛋白NR(LPNR)胶乳和NR胶乳在氮气气氛中的热降解性能。结果表明，LPNR胶乳和NR胶乳的热降解过程相似，热降解反应级数相差不大，热降解率均随升温速率增大而略有增大；NR胶乳的平衡起始降解温度较高，LPNR胶乳的平衡最大降解速率温度和平衡终止降解温度与NR胶乳相近；LPNR胶乳的热稳定性比NR胶乳差。     

天然胶乳手套与合成胶乳手套的发展

介绍天然胶乳手套的起源和发展以及天然胶乳检查手套、外科手套、织物浸渍防护手套、家用手套、工业手套的用途、规格、特点和表面形式,指出因天然胶乳手套存在安全性能和使用性能的不足,促进了合成胶乳手套和人造胶乳手套的发展。丁腈胶乳检查手套因技术进步和成本降低成为天然胶乳检查手套的主要竞争者;低蛋白无粉天然胶乳外科手套、氯丁胶乳外科手套和聚异戊二烯胶乳外科手套成为对天然胶乳过敏症医护人员的选择;在非医疗领域,合成胶乳手套和人造胶乳手套适用于特殊领域的防护需求。     

一种多官能团乳化剂在羧基丁苯胶乳合成中的应用

试验发现：一种阴离子型兼具非离子性的乳化剂A用于羧基丁苯胶乳聚合体系，可显著提高胶乳的质量，其质量分数即使下降到原配方乳化剂标准用量的25％，也能制备出合格的胶乳；与使用SDS的聚合体系相比，使用乳化剂A的聚合体系的聚合反应及产物质量重复性好，胶乳的钙离子稳定性显著提高。分析发现，乳化剂用量的大小会导致聚合反应机理的差异，从而影响聚合反应及产物质量；在酸性条件下，乳化剂本 身的稳定性也是造成这种差异的原因之一。应用试验结果表明：用乳化剂A代替SDS并在一定范围内改变其用量，不会影响胶乳的应用性能。