丙烯酸酯-聚氨酯核壳乳液的合成

采用种子乳液聚合法和核壳技术制备了丙烯酸酯改性聚氨酯乳液(PUA)。聚合过程中用丙烯酸羟乙酯作为封闭剂,用丙烯酸酯单体代替溶剂,检测结果表明PUA乳液膜耐水性、耐水压和拉伸强度等性能明显优于聚丙烯酸酯乳液(PA)和PU/PA。     

丙烯酸酯改性水性聚氨酯乳液的合成及性能研究

采用核-壳聚合法制备了丙烯酸酯改性水性聚氨酯(PUA)乳液,通过红外、透射电镜、差示扫描量热法对乳液的形态及结构进行了表征;研究了聚合温度、引发剂种类及用量、丙烯酸酯加入量对乳液及涂膜性能的影响。结果表明:制备的为核壳型PUA复合乳液,当聚合温度在70～75℃,采用油溶性引发剂偶氮二异丁腈,用量为2.0%～2.5%时,可得到性能较佳的乳液,制得的PUA涂膜耐水性、稳定性以及力学性能有明显提高。     

聚氨酯/丙烯酸酯复合乳液

<正>近年来,许多研究者利用聚氨酯(PU)乳液和丙烯酸酯(PA)乳液共聚具有性能互补的作用,制备了聚氨酯/丙烯酸酯(PUA)复合乳液。虽然,PUA复合乳液较单一乳液性能好,但是其涂膜的硬度、耐水性和耐化学品性还难以满足高档水性木器涂料的要求。     

A／U-g-A型核壳聚氨酯-丙烯酸酯复合乳液的合成

通过加入双官能团单体甲基丙烯酸-β-羟乙酯(HEMA),采用溶液聚合法和原位乳液聚合法,把聚氨酯与丙烯酸(AA)、丙烯酸丁酯(BA)和苯乙烯(St)等丙烯酸酯单体接枝共聚,合成了PUA为壳、PA为核的聚氨酯-丙烯酸酯(PUA)复介乳液.研究了壳层PA/Pu、总PA/PU、核壳比、BA/St、壳层HEMA/PA和链转移剂含量对乳液制备过程、乳液及涂膜性能的影响.研究结果表明:PUA中的PA、BA、St、HEMA,链转移剂和DMPA与AA中的-COOH的含量(壳层PUA的质量分数)分别为55.6%、25%、17.8%、9%、1%和7%,核壳质量比为1:4时,复合乳液涂膜结构规整,各项性能较好.PUA胶粒的平均粒径在100 nm左右时,分布更均匀.     

水性聚氨酯-丙烯酸酯复合乳液的性能研究

用丙烯酸酯改性水性聚氨酯制备了具有核壳结构的水性聚氨酯-丙烯酸酯(WPUA)复合乳液,系统地研究了水性聚氨酯(PU)含量、nNCO/nOH(初始物质的量比)、亲水性扩链剂二羟甲基丙酸(DMPA)用量及软硬单体质量比对WPUA乳液及其膜的性能的影响.结果显示,WPUA乳液胶粒呈核壳型结构,聚丙烯酸酯(PA)与PU链段具有...     

聚氨酯-丙烯酸酯复合乳液成功合成

聚氨酯-丙烯酸酯复合乳液虽然较单一乳液的性能有很大改善,但是其涂膜的硬度、耐水性、耐化学品性还难以满足高档水性木器涂料的要求。最近,湖南大学化学化工学院在聚氨酯-丙烯酸酯复合乳液中,以不同方式加入环氧树脂,分别制备了物理共混和化学共聚的聚氨酯-丙烯酸酯-环氧树脂复合乳液（PUEA）,着重研究了环氧树脂加入方式、用量等对乳液及涂膜性能的影响。发现环氧树脂对于涂膜的硬度、耐水性、耐化学品性等有明显改进．研究还表明,环氧树脂的质量分数在3％～4％为宜。近年许多研究者利用PU乳液和PA乳液性能上具有的良好互补作用,共聚制备聚氨酯-丙烯酸酯（PUA）复合乳液;在先前的PUA复合乳液研究基础上,加入环氧树脂,合成环氧树脂改性的聚氨酯-丙烯酸酯（PUEA）复合乳液,可使其涂膜的吸水率显著降低,硬度与其他有关性能也有一定提高。     

丙烯酸酯对水性聚氨酯胶粘剂的改性研究

用自乳化的方法制备水性聚氨酯(PU)乳液,然后用丙烯酸酯进行改性,制备出水性聚氨酯和丙烯酸酯共聚乳液(PUA),并把聚丙烯酸酯(PA)乳液与PU乳液不同比例共混。考查了共聚型和共混型PUA乳液胶膜的吸水性、热行为、黏度、T型剥离强度。结果表明,在复合薄膜应用方面,共聚型PUA乳液的性能优于共混型PUA乳液。     

水性聚氨酯/丙烯酸酯复合乳液的合成及其性能研究

通过自由基乳液聚合,合成具有核壳结构的水性聚氨酯/丙烯酸酯复合乳液(PUA)。用IR、DSC和TEM对产物结构进行了表征,证明水性聚氨酯(PU)与丙烯酸酯单体在实验条件下发生了共聚反应;考察了PVA乳液及其胶膜耐热性和耐溶剂性。结果表明具有核壳结构的PUA乳液的各项性能均比水性聚氨酯有明显提高。     

四配位硅/丙烯酸醋改性水性聚氨醋的制备及性能

采用四配位硅单体对丙烯酸酯、聚氨酯杂合水分散体进行改性,制备出具有核壳结构的共聚乳液(Si-PUA).研究了MMA添加量对Si-PUA乳液及涂膜性能的影响.并利用红外光谱(IR)、热失重(TG)、差示扫描量热(DSC)分析等手段分别进行了表征.研究表明:随着MMA含量的增加,体系聚合稳定性变差,MMA的适合添加量为Si-PUA总质量的20%～30% ; PUA涂膜的耐水性和耐溶剂性明显优于PU涂膜,而用四配位硅单体改性后的Si-PUA涂膜,改性效果更加显著.IR表明,MMA、四配位硅单体是参加了聚合反应;DSC表明通过MMA和四配位硅的改性,使得PU的软段和硬段的相容性增加.TG表明改性后的水性聚氨酯耐高温性能有所提高.     

水性聚氨酯的改性研究

分别采用丙烯酸酯、环氧树脂合成2种不同的改性水性聚氨酯,比较了改性前后及2种不同的改性水性聚氨酯在乳液、涂膜性能及粘接性能方面的差异。结果表明,改性后的水性聚氨酯综合性能明显提高,其中环氧树脂改性水性聚氨酯(EPU)在固化交联后涂膜的耐水、耐溶剂及力学性能又明显好于丙烯酸酯改性水性聚氨酯(PUA),其粘接强度与溶剂型聚氨酯相当;而采用丙烯酸酯改性的水性聚氨酯PUA乳液稳定性好于EPU乳液。     

丙烯酸酯改性水性聚氨酯核壳复合乳液工艺探究

为了探究聚合工艺对丙烯酸酯(PA)改性水性聚氨酯(PU)性能的影响,选用不同的聚合工艺,合成了具有核壳结构的PUA复合乳液.通过高分辨透射电镜(TEM)、傅里叶红外光谱(FT-IR)、拉伸力学测试和热重(TG)等测试手段比较了不同工艺和引发剂类型对共聚物乳液形态和胶膜性能的影响.研究结果显示,使用偶氮二异丁腈( AIBN)作为引发剂,采用PA单体前乳化法可以得到具有明显核壳结构的复合乳液,乳胶膜综合性能最好,PU和PA具有更好的相容性.     

Morphology and particle size of nanograde polyurethane/polyacrylate hybrid emulsions

Poly(urethane acrylate) (PUA) composite particles were prepared by seeded surfactant‐free emulsion polymerization. The aqueous polyurethane (PU) dispersions were used as seed particles. The diameters of the seed particles of the aqueous PU dispersions and PUA composite latexes were measured by dynamic light scattering. The microstructures of the PUA composite emulsion particles were observed by transmission electron microscopy. The influences of the amount of the hydrophilic chain extender, the types of initiators, and the PU/polyacrylate (PA) weight ratios on the diameters of the aqueous PU and composite emulsions were also studied. The results showed that the PUA composite emulsions formed a core–shell structure with PU as the shell and with PA as the core. The diameter of the PU seed particles and the particle size of the PUA composite emulsions greatly depended on the amounts of the hydrophilic chain extender used in the preparation of the PU seed; when the hydrophilic chain extender concentration was 7.4%, the average diameter of the PUA composite emulsion particles showed the minimum value. The types of initiators and PU/PA weight ratios did not have a significant influence on the diameter of the PUA composite latex particles. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Aqueous PUA emulsion prepared by dispersing polyurethane prepolymer in polyacrylate emulsion

Waterborne polyurethane/polyacrylate (PUA) emulsions were prepared by dispersing polyurethane (PU) prepolymer in polyacrylate (PA) emulsion; therefore, the PU particles formed in the presence of PA nanoparticles. The particle size and its distribution of the composite PUA emulsion were determined by dynamic light scattering. The result shows that the average particle size increases initially and then decreases with increasing PA content, which is confirmed by transmission electron microscope characterization. The surface properties of PUA films were analyzed by water contact angle and atomic force microscope topography. It indicates that the water contact angle and the average roughness of the composite PUA films are larger than those of the PU film. Meanwhile, mechanical properties test, scanning electron microscopy, and thermogravimetric analyses disclose that the PUA films are characterized by enhanced tensile strength, rough fractured surface, and good thermal stability. The preparation method proposed in this article is an effective and convenient way to manufacture composite PUA emulsion. The composite PUA emulsion can be potentially used in coatings. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43203.     

蓖麻油和环氧树脂改性水性聚氨酯-丙烯酸酯的合成与表征

以甲苯二异氰酸酯(TD I)、聚醚型多元醇(N210)、2,2-二羟甲基丙酸(DMPA)、甲基丙烯酸甲酯(MMA)等为主要原料,蓖麻油(C.O.)和脂肪族环氧树脂(RE)为交联剂,以原位乳液聚合法制备出聚氨酯-丙烯酸酯(PUA)复合乳液。以无皂乳液聚合法合成了聚丙烯酸酯乳液(PA),再与聚氨酯(PU)乳液机械混合得到PU/PA共混乳液。探讨了蓖麻油C.O.、RE对复合乳液及涂膜性能的影响,烯丙氧基羟丙基磺酸钠(COPS-1)用量对共混乳液和涂膜性能的影响。结果表明,C.O.、RE分别占PU干质量的5.0%～7.0%和2.0%～3.0%,COPS-1占单体总质量的2.0%时,乳液和涂膜综合性能较好。PUA比PU/PA柔韧性好、断裂伸长率高及附着力好,硬度低,成本高。红外光谱分析发现,PUA与PU/PA中—NH—全部形成氢键。TEM观察到,PUA形成核-壳结构的粒子,粒径较小。通过AFM扫描发现,PUA存在硬段与软段的微相分离。     

丙烯酸树脂改性水性聚氨酯的结构与性能研究

采用丙烯酸树脂对水性聚氨酯进行改性，得到了共混改性（PU／PA）、共聚改性（PUA’）、接枝改性（PUA）3种丙烯酸改性水性聚氨酯聚合物。通过对改性聚氨酯乳液的激光粒度分析，乳胶膜的红外光谱、热分析、透明性、耐化学性及扫描电镜进行分析，结果表明：改性后的水性聚氨酯，各项性能均有不同程度的提高。在机械共混聚合物PU／PA体系中，聚氨酯分子链和丙烯酸树脂分子链间具有一定的相容性及共混性；在共聚反应聚合物PUA’、PUA体系中，聚氨酯分子链和丙烯酸树脂分子链形成核壳结构，且在PUA中，聚氨酯分子链和丙烯酸树脂分子链之间形成的化学键，可以有效的提高二者的相容性及共混程度。     

低亲水基丙烯酸酯-聚氨酯复合乳液涂膜的热分析研究

以异佛尔酮二异氰酸酯(IPD I)、聚已二酸-1,4丁-二醇酯(PBA)、二羟甲基丙酸(DMPA)、丙烯酸酯(PA)为主要原料,采用自乳化工艺制备了固体质量分数均为40%,亲水基团(DMPA的羧基)占固体质量百分数为1%的一系列稳定的聚氨酯-丙烯酸酯复合乳液(PUA);用热重分析(TG)、示差扫描量热分析(DSC)、动态机械热分析(DMA)方法研究PBA的相对分子质量、聚氨酯与丙烯酸酯的质量分数比(PU/PA)对PUA膜热性能的影响。热分析研究表明,增加PBA相对分子质量和加入适量的丙烯酸酯能提高PUA分子的有序程度,有利于PUA成膜物耐热性能的改善;随着PBA相对分子质量的增加,PU软段的非晶部分和PA的硬段相容性增强,微观相分离减小,乳液的混合能达到分子水平。     

蓖麻油聚氨酯-丙烯酸酯复合乳液的合成

采用甲基丙烯酸甲酯（MMA）与蓖麻油水性聚氨酯乳液共聚反应制备聚氨酯丙烯酸酯（PUA）复合乳液,研究了蓖麻油水性聚氨酯性能、MMA添加量、引发剂种类和聚合温度对PUA复合乳液及涂膜性能的影响,并应用傅里叶红外光谱（FTIR）测定反应产物的结构.研究发现,用外观半透明或微透明的PU-M分散液制备的PUA乳液及涂膜性能优良.油溶性引发剂（AIBN）比水溶性引发剂（K₂S₂O₈）更适合本体系的乳液聚合.随着MMA含量增大,PUA复合乳液胶粒粒径增大,黏度减小,涂膜光泽度下降,机械性能变好,耐水性增加.合适的MMA含量为体系总固含量的20%～30%.提出了PUA复合乳液胶粒形成及粒径长大机理.     

Preparation,mechanical properties of waterborne polyurethane and crosslinked polyurethane‐acrylate composite

The waterborne polyurethane (PU) prepolymer was first prepared based on isophorone diisocyanate, polyether polyol (NJ‐210), dimethylol propionic acid (DMPA), and hydroxyethyl methyl acrylate via in situ method. The crosslinked waterborne polyurethane‐acrylate (PUA) dispersions were prepared with the different functional crosslinkers. The chemical structures, optical transparency, and thermal properties of PU and PUA were confirmed by Fourier transform infrared spectrometry, ultraviolet–visible spectrophotometry, and differential scanning calorimetry. Some physical properties of the aqueous dispersions such as viscosity, particle size, and surface tension were measured. Some mechanical performances and solvent resistance of PUA films were systemically investigated. The experimental results showed that the particle sizes of the crosslinked PUA aqueous dispersions were larger than the PU and increased from 57.3 to 254.4 nm. When the ratios of BA/St, BA/TPGDA, and BA/TMPTA were 70/30, PUA films exhibited excellent comprehensive mechanical properties. The tensile strength and elongation at break of the film were 2.17 MPa and 197.19%. When the ratio of BA/St was 30/70, the film had excellent water resistance and was only 6.47%. The obtained PUA composites have great potential application such as coatings, leather finishing, adhesives, sealants, plastic coatings, and wood finishes. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012