【作者】 王东；

【导师】 李小瑞； 费贵强；

【作者基本信息】 陕西科技大学 ， 应用化学， 2016， 硕士

【摘要】 随着对挥发性有机化合物(VOC)排量的限制愈加严格,各种法规亦相继出台,新环保法规亦规定VOC是雾霾的重要来源之一,因此,节能环保产品的开发愈加受到重视。开发低溶剂、高固含量、廉价且性能优异的水性树脂已成为涂料领域的当务之急。紫外光(UV)固化技术作为一种环保高效节能的固化技术,具有很多优点,如固化速度快、节省能源、低VOC排放量等,近年来成为研究热点。传统水性光固化聚氨酯体系在性能上仍然存在部分缺陷,如固含量低、成膜速度慢、运输成本较高；涂膜的力学性能、耐候性、耐溶剂性等不理想,导致其在应用上受到一定的限制。为进一步提高固含量、光固化效率和产品性能,本研究分别引入了磺酸盐型聚酯多元醇(BY3301)、聚乙烯醇0588(PVA)、聚乙烯醇缩丁醛(PVB)等组份,通过分子设计,对水性光固化聚氨酯进行了系列改性,成功制备了高性能的水性光/氧双固化聚氨酯乳液；深入研究了乳液的制备方案及其与胶膜的构效关系。(1)BY3301、聚己内酯二元醇(PCL,Mn=1000)和异佛尔酮二异氰酸酯(IPDI)等为单体,制备出了高固含量磺酸盐型水性紫外-氧气双固化聚氨酯乳液(UV-SWPU)。通过动态光散射仪、原子力显微镜(AFM)热重(TG)、扫描电镜(SEM)等测试方法研究了m(PCL)/m(BY3301)比例对乳液以及乳胶膜微观形貌、力学性能、耐水性和热稳定性的影响。结果表明,随着BY3301的含量的增加,乳液的固含量由38%增加至55%,乳液的平均粒径由33.70 nm增加至50.94 nm,分布系数有所增加；乳胶膜拉伸强度由46.7 MPa提高至55.65 MPa,吸水率降低,乳胶膜表面粗糙度增加,热稳定性提高。但当BY3301含量高于16.7%时,乳胶膜的力学性能和耐水性下降；当BY3301含量高于33.3%,乳液粒径和分布系数有所下降。与单一氧气固化和单一紫外固化相比,紫外-氧气双固化体系可明显改善乳胶膜的拉伸强度和耐水性。涂层应用性能测试表明当BY3301含量在26.7%时,综合性能较为理想。(2)以BY3301、IPDI、季戊四醇三丙烯酸酯(PETA)为主要原料,二羟甲基丁酸(DMBA)作为亲水扩链剂,采用丙酮法合成了磺酸盐紫外固化水性聚氨酯(UV-SWPU),再将其与PVA溶液机械共混制得UV-SWPU/PVA共混乳液。采用了红外光谱(FT-IR)和X射线衍射(XRD)表征了聚合物结构和结晶性能,通过动态光散射仪、SEM等方法研究了乳液粒径、截面形貌等。结果表明,随着PVA含量的增高,乳液粒径增加,乳液粒径分布曲线和微分热重曲线均呈单峰分布,粒径分布系数变化不大,两者相容性较好。UV-SWPU/PVA胶膜结晶性、力学性能均提高,断裂伸长率下降,乳胶膜呈现脆性断裂；乳胶膜的吸水率上升,接触角下降。(3)以IPDI、聚乙烯缩丁醛(PVB)、PETA、 DMBA和马来酸酐(MA)等为原料,首先通过自由基聚合法,合成了水性中间体PVB接枝改性物PVB-M;并通过改变PVB-M的含量,制得系列UV固化型水性聚氨酯(UV-WPBU);并通过FT-IR,TG、XRD、AFM、SEM和DMA等方法对聚合物进行了表征。通过FT-IR证实了UV-WPBU的结构。随着PVB-M含量的增加,乳液的粒径由29.87 nm增加至79.95 nm;且当PVB-M的含量高于8.53%时,乳液的稳定性下降,粒径急增至428.9 nm。随着PVB-M的增加,吸水率从51.34%降至11.93%,接触角由920增加至1030,PVB-M的引入可明显提高胶膜的耐水性。乳胶膜的拉伸强度呈现先增大后减少的趋势,PVB-M的含量为8.53%时,达到最大值41.31 MPa;而断裂伸长率逐渐减少。乳胶膜的结晶度由23.17%降至0.70%,断裂由脆性断裂转变为韧性断裂；此外,胶膜的储能模量增加,分子间相互作用增强,微相分离程度下降。热分析亦表明热稳定性能随着PVB-M含量的增加而提高。凝胶量测试表明,适量PVB-M的引入可明显提高涂层的紫外光固化性能。更多还原

【Abstract】 Along with the increasingly strict limits on the VOC emissions, various regulations were formulated, and VOC has been specified as the source of atmopheric haze. Therefore, energy-saving and environmental products get more and more attention. And it is urgent and important to develop high cost-performance and environmental waterborne resin with high solid content in the field of coating. UV-curing technology has become a research hotspot in recent years. Curing technology owns multiple advantages like fast curing speed, energy-saving, low VOC emissions, etc. However, the application of ordinary UV-curable waterborne polyurethane was restricted due to several defects, such as low solid content of product, slow film-forming, high cost, poor mechanical properties and disappointing performance of weather resistance and solvent resistance. In this paper, to improve the solid content, curing efficiency and product performace, sulfonate polyester polyol (BY3301), polyvinyl alcohol of (PVA), and polyvinyl butyral (PVB) have been introduced, respectively. And a series of UV curable waterborne polyurethanes with high performance were prepared based on molecular design. The preparation scheme and the relationship between structure and properties of composite emulsions and films were discussed.(1)A series of waterborne UV-oxygen curable sulphonate polyurethane were synthesized with isophorone diisocyanate as hard segment, poly(caprolactone glycol)(PCL1000) and sulfonate polyester polyol (BY33O1) as soft segment. Effects of m(PCL)/m(BY3301) on film morphology, mechanical property, water resistance and thermal stability were characterized by Fourier transform infrared spectroscopy(FTIR), dynamic light scattering(DLS), transmission electron microscope(TEM), atomic force microscope(AFM), thermal gravimetric analysis(TG), scanning electron microscope(SEM) and other methods. With increasing BY3301 content, the solid content of emulsion increased from 38% to 55%. Meantime, the particle size increased from 33.70 nm to 50.94 nm, and the distribution was also slightly increased. The tensile strength of emulsion film increased from 46.7 nm to 55.65 MPa; The water absorption decreased, and the surface roughness increased, as well as the thermal stability. However, the mechanical property and thermal stability decreased when BY3301 content was greater than 16.7%. The particle size and distribution index of emulsion reduced when BY3301 content was greater than 33.3%. Compared with separate UV and oxygen curing method, UV-O2 dual-curing method was beneficial to significantly improve the tensile strength and water resistance of emulsion films. The application performance tests revealed that the comprehensive properties reached optimum when the BY3301 content was 26.7%.(2)Sulphonate waterborne UV-curable polyurethane (UV-SWPU) was prepared by acetone method, using isophorone diisocyanate (IPDI), sulphonate type polyester polyol (BY3301) and pentaerythritol triacrylate (PETA) as main materials, and dimethylolbutyric acid as hydrophilic chain extender. Afterwards, the obtained UV-SWPU emulsion was mixed with polyvinyl alcohol (PVA) solution to prepare UV-SWPU/PVA blend emulsion. The structure and crystallization properties of blend films were characterized by FTIR and X-ray diffraction. In addition, the emulsion particle size and cross-sectional morphology were investigated by dynamic light scattering instrument and scanning electron microscopy. It was found that the particle size increasing as increasing PVA content. The particles size distribution curves and differential thermogravimetric curves displayed as unimodal distribution, and slight change take place in distribution index, indicating better compatibility between UV-SWPU and PVA.(3)UV-curable waterborne polyurethane (UV-WPUB) was prepared by acetone method using IPDI, PCL1000 and 2,2-dimethylol butanoic acid (DMBA), polyvinyl butyral (PVB), PETA, and maleic anhydride (MA) as main materials. First, grafted polyvinyl butyral material (PVB-M) was prepared by modification of polyvinyl butyral (PVB) with maleic anhydride via free radical polymerization. The structure and properties of polymer were characterized with FTIR, DLS, AFM, TQ SEM and other methods. The structure of UV-WPUB was demonstrated by FTIR. With increasing PVB-M content, the particle size of UV-WPUB emulsion increased from 29.87 nm to 79.95 nm. However, the stability of emulsion decreased and particle size increased abruptly to 428.9 nm when the PVB-M content was greater than 8.53%. In addition, the water absorption decreased from 51.34% to 11.93%, and contact angle increased from 92° to 103°, the water resistance was greatly enhaced by the incorporation of PVB-M. The tensile strength increased first and then decreased, and reached the maximum value of 41.31 MPa when the PVB-M content was 8.53%. Whereas the elongation at break decreased. The crystallization degree decreased from 23.17% to 0.70%, and the fracture mode transferred from brittle fracture to ductile fracture. Moreover, the storage modulus increased, as well as the intermolecular interaction, and the microphase separation was weakened. Thermal analysis indicated that the thermal stability increased with increasing PVB-M content. Furthermore, the UV-curing properies were also improved with certain amount of PVB-M.更多还原