纳米SiO_2/聚氨酯丙烯酸酯预聚物的制备和性能研究

利用纳米SiO2表面Si—OH和异氰酸酯化合物反应的特点,将其与异佛尔酮二异氰酸酯(IPDI)、聚丙二醇(PPG)和丙烯酸羟乙酯(HEA)进行原位聚合制备纳米SiO2/聚氨酯丙烯酸酯预聚物。将该预聚物应用于光固化涂料,并对涂料的光敏性能、黏度及其固化膜的耐热性能、硬度和耐磨性能进行了研究。结果表明:纳米SiO2在紫外光固化涂料中团聚现象少,分散性能好。采用纳米SiO2/聚氨酯丙烯酸酯预聚物,所制涂料固化膜的初始热分解温度提高,硬度和耐磨性能均有显著改善,但涂料的透明性和光固化速率降低,黏度增大。     

纳米SiO2在有机硅涂料中的分散性研究

利用纳米SiO2粒子所具有的特殊性能,研制出新的有机硅基纳米SiO2防护涂料.纳米SiO2粒子在有机硅中的分散和稳定性问题是制备纳米SiO2有机硅涂料的关键.为了解决纳米SiO2粒子在有机硅中的分散性和稳定性,对纳米SiO2粒子进行了表面改性处理,从而改变了纳米SiO2粒子表面的理化性能,同时利用物理分散和化学分散相结合的方法进行纳米SiO2在有机硅涂料中的分散,采用适合的制造工艺制备纳米SiO2有机硅涂料.通过透射电镜(TEM)、傅立叶变换红外光谱(FTIR)等技术分析了纳米SiO2粒子在有机硅涂料中的分散性和稳定性.     

鞣酸改性纳米二氧化硅对UV固化涂料性能的影响

通过在纳米二氧化硅-乙醇悬浮液中加入一定量鞣酸的方法,在纳米二氧化硅表面引入羟基等活性基团对纳米二氧化硅进行表面改性,并用SEM、FTIR和TG等手段对鞣酸表面改性纳米二氧化硅的改性机理进行研究。利用交流阻抗图谱(EIS)研究包覆后二氧化硅对UV固化涂料的防腐蚀性能。结果表明:鞣酸是以化学键合的方式接枝到纳米二氧化硅表面,改性后的纳米二氧化硅分散良好,鞣酸改性纳米SiO2能极大提高UV固化涂层防腐蚀效果。     

纳米SiO_2表面接枝甲基丙烯酸甲酯的研究

为了提高纳米二氧化硅(SiO2)粒子在阻燃型聚合物基纳米复合材料中的有效利用,需要对粒子的表面进行改性。此实验采用溶液聚合法,使甲基丙烯酸甲酯单体(MMA)在烷基化预处理的纳米SiO2粒子的表面进行接枝聚合,得到以纳米SiO2粒子为核、接枝聚甲基丙烯酸甲酯为壳的复合颗粒(SiO2-g-PMMA)。结果表明,PMMA以化学键成功地接到纳米SiO2的表面,并可通过改变接枝聚合的条件来调节粒子上所接聚甲基丙烯酸甲酯的结构,改性后的纳米SiO2粒子具有良好的热稳定性及分散性。     

纳米粒子／环氧树脂复合材料的固化动力学研究

为了改善纳米SiO2粒子在环氧树脂基体中的分散性,提高无机粒子与基体的界面结合力,文章选择马来酸酐和苯乙烯单体在粒予表面进行接枝改性。改性粒予与环氧树脂在固化条件下基本不发生反应,而固化剂2-乙基-4-甲基咪唑使得改性粒子上的酸酐开环生成羧酸;固化动力学分析表明：纳米粒子表面的羟基对环氧树脂的固化起促进作用;与未改性的粒子相比,填充SiO2-SMA粒子的固化体系的粘度较低,所以固化起始温度降低,但反应活化能较高。     

光固化纳米二氧化硅/环氧丙烯酸酯杂化涂料的制备与表征

通过在纳米SiO2粒子表面锚固热引发剂,然后在活性稀释单体中对纳米SiO2进行原位接枝聚合改性.将改性纳米SiO2和活性稀释单体的混合物直接与其他原料共混,制备了光固化纳米SiO2/环氧丙烯酸酯(EA)杂化涂料.采用傅立叶变换红外光谱(FTIR)、扫描电镜(SEM)、热重分析(TG)和涂膜性能试验等对杂化涂料的结构与性能进行了研究.结果表明,聚合物链段通过化学键接枝到了纳米SiO2粒子表面;改性后的纳米SiO2在杂化膜中分散良好;在引入改性纳米SiO2后,涂膜的耐热性、抗冲击性、硬度、附着力等性能得到显著改善.     

纳米改性SiO2填料对光固化涂料耐腐蚀性的影响

用偶联剂6040对纳米SiO2表面进行了改性,并将改性后的SiO2加入到有机硅改性环氧丙烯酸酯中,制得光固化涂层。用XRD、FF—IR对改性后的纳米SiO2进行了表征;用SEM、EIS技术考察了填料改性对光固化涂层耐腐蚀性能的影响。结果表明：改性后SiO2由晶态转变为非晶态;并且改性后SiO2的表面带有偶联剂的特征基团;填料改性后在光固化涂层中的分散性良好,涂层耐腐蚀性大大提高。     

聚苯乙烯/纳米SiO_2复合材料的制备

经硅烷偶联剂KH-570改性后的纳米SiO2表面具有大量可反应性基团-CH=CH2。以苯乙烯和改性后的纳米SiO2为原料,利用自由基聚合反应,制备得到聚苯乙烯/纳米SiO2复合材料。FT IR和TG证明聚苯乙烯大分子链已成功接枝到纳米SiO2粒子表面。由于扩散作用的影响,相对于偶氮二异丁腈引发聚合反应,热聚合反应具有更高的接枝率。     

纳米复合外墙乳胶漆的研制

在传外墙乳胶漆的基础上，加入纳米TiO2和SiO2等粒子，并采取表面改性和超声波分散的方法，使纳米粒子在涂料体系中得到有效分散，从而提高涂料的综合性能。着重讨论了纳米粒子的分散性及其用量，以及纳米粒子表面改性剂对涂料性能的影响。     

Sol-Gel法制备光固化纳米复合涂料的应用性能

运用紫外光固化技术与溶胶-凝胶（Sol-Gel）法制备紫外光固化纳米复合涂料,考察了SiO2含量及有机树脂结构对涂膜性能的影响.结果表明复合涂料中纳米颗粒具有良好的分散性,并在其表面形成良好的界面结合层;纳米SiO2的加入可以改善涂膜的硬度、附着力和抗冲性能.用该方法得到的EA/PUA纳米复合涂料光固化后涂膜具有优良的综合性能.     

Surface modification of nanosilica with 3-mercaptopropyl trimethoxysilane and investigation of its effect on the properties of UV curable coatings

This paper describes surface modification of commercial nanosilica with 3-mercaptopropyl trimethoxysilane (MPTMS) and its effect on the properties of UV curable coatings. The mercapto groups were grafted onto nanosilica surface by a condensation of the surface Si–OH with the hydrolysized Si–OH of MPTMS. Fourier transform infrared spectroscopy, thermal gravimetric analysis, and particle size distribution were employed to characterize nanosilica and modified nanosilica. It was demonstrated that the mercapto groups were successfully grafted onto the nanosilica surface with the grafting ratio of 16.8% and the mercapto groups content of 0.9 mmol/g. The dispersion and self-aggregation of nanosilica in UV curable coatings were improved significantly. The photopolymerization kinetics of UV curable coatings, containing various amounts of nanosilica and modified nanosilica, were evaluated by the photo differential scanning calorimetry technique. This indicated that nanosilica both before and after modification decreased UV curing speed and ultimate percentage conversion; however, in comparison with the coatings containing unmodified nanosilica, the coatings containing modified nanosilica exhibited higher curing speeds and conversion ratios. It can be ascribed that the mercapto groups on the nanosilica surface reduced oxygen inhibition during the UV curing process via the thiol–ene click reaction. The mechanical properties of UV curable coatings were also compared.     

Preparation and properties of polymerizable silica hybrid nanoparticles with tertiary amine structure

To increase the photopolymerization rate and improve the properties of UV coatings, polymerizable silica hybrid nanoparticles with tertiary amine structure were prepared. Organic compound with isocyanate group was first grafted onto the surface of nanosilica by reaction of nanosilica with isophorone diisocyanate, then the nanosilica bearing isocyanate group reacted with N,N-di(3-propionic acid, 1,4,7-trimethyl-3,6-dioxaoctane-8-yl acrylate, ester) ethanolamine synthesized from tripropylene glycol diacrylate and ethanolamine. The preparation was characterized by ¹H nuclear magnetic resonance (NMR) and Fourier transform infrared spectrometry (FT-IR). Thermogravimetric analysis (TGA) showed that the organic compounds grafted onto the silica decomposed from 256 °C to 650 °C and the grafting percentage based on nanosilica was 105%. The morphology analysis of nanosilica and modified silica by field-emission scanning electron microscopy (FE-SEM) indicated that the silica kept nanosized scale after modification, while the nanosilica dispersion was improved and formation of agglomerates unlikely. Determination of viscosities of coatings with modified nanosilica, it was found that viscosities of the coatings decreased in comparison with the viscosities of coatings with unmodified nanosilica. Compared with pure organic coating, the photopolymerization rate of coatings were faster when modified nanosilica was used from 1 wt% to 5 wt%, but slower when the loadings of modified nanosilica was 7 wt% because co-initiating effects of tertiary amine compound grafted on nanosilica counterbalanced the effects of UV scattering by silica on photopolymerization rate. The hardness and abrasive resistance of cured films also increased and improvement degree was different when the various amounts of modified nanosilica were used.     

聚氨酯丙烯酸酯软段结构对UV胶性能的影响

以几种不同结构的多元醇、异佛尔酮二异氰酸酯(IPDI)和丙烯酸羟乙酯为原料,合成了多种聚氨酯丙烯酸酯预聚物(PUA).按照同样比例的单体、引发剂及其他助剂配制成光固化胶粘剂(UV胶),考察了聚氨酯中多元醇结构对UV胶固化速度、黏结强度、胶膜性能等的影响.结果表明,聚氨酯结构中软段结构对UV胶粘剂性能影响比较大,合理地选...     

Surface modification of nanosilica with acrylsilane-containing tertiary amine structure and their effect on the properties of UV-curable coating

In order to improve the dispersion of nanosilica and the mechanical properties of UV-curable coating, nanosilica was modified with acrylsilane-containing tertiary amine structure, which was synthesized by the Michael addition reaction between 3-aminopropyl triethoxysilane and tripropylene glycol diacrylate. The prepared acrylsilane was characterized by ¹H NMR, ¹³C NMR, and FTIR. The modified nanosilica was characterized by FTIR, TGA, and SEM. The TGA analysis showed that the grafting percentage of acrylsilane based on nanosilica was 72.4 wt%. The SEM results showed that the agglomeration of nanosilica was reduced and the dispersion was improved due to the acrylsilane modification. The viscosities of UV-curable coatings with modified nanosilica were determined and it was found that the viscosities of the coatings decreased in comparison with the viscosities of coatings with unmodified nanosilica. The photo-DSC results indicated that both nanosilica and modified nanosilica also decreased the UV-curing speed and final percentage conversion, while the conversion of the coatings containing modified nanosilica was faster than that with unmodified nanosilica owing to the tertiary amine structure and acrylate structure on the surface of the modified nanosilica.     

PUA改性磷酸酯的合成及其光固化性能研究

以聚醚二元醇和POCl3为原料合成了含磷三元醇聚合物,再与异佛尔酮二异氰酸酯(IP-DI)、丙烯酸羟乙酯(HEA)反应,制成了聚氨酯丙烯酸酯(PUA)改性磷酸酯,通过红外光谱进行分析表征。将合成的PUA改性磷酸酯添加在紫外光固化胶粘剂中分析测试了其应用性能,并与紫外光固化胶粘剂(UV胶)中常用的磷酸酯类附着力促进剂进行了对比。结果表明,POCl3与聚醚二元醇在40℃下反应4 h可以得到预期的含磷三元醇。得到的PUA改性磷酸酯与UV胶粘剂中常用的磷酸酯相比,附着力、粘接强度可以达到其要求,但是酸值低于现有的磷酸酯,更适合在UV胶粘剂中应用。     

UV固化蓖麻油基聚氨酯丙烯酸酯/SiO2杂化材料的制备与性能Q

以异佛尔酮二异氰酸酯（IPDI）、蓖麻油（CO）和丙烯酸羟乙酯（HEA）合成了蓖麻油基聚氨酯丙烯酸酯（COPUA），以正硅酸乙酯（TEOS）和3-(异丁烯酰氧)丙基三甲氧基硅烷（MEMO）通过溶胶-凝胶法制备了改性硅溶胶，作为无机相与COPUA有机相复合得到了UV固化COPUA/SiO2杂化材料。调节MEMO与TEOS的配比得到一系列改性硅溶胶，通过测试确定了MEMO与TEOS的最佳配比为1：1（MT-1）。在此基础上，改变MT-1的添加量得到UV固化COPUA/SiO2杂化材料。用FT-IR、TEM、SEM、TGA等对杂化材料和涂层进行结构表征，测试复合涂层的力学性能和表面性能。当MT-1添加量为COPUA树脂质量的15%时，涂层内部SiO2粒子分布均匀，涂层表面光滑平整，光透过率达到100.2%，硬度为5H，附着力0级，柔韧性1mm；涂膜拉伸强度达到13.52MPa，断裂伸长率为7.49%。     

聚己内酯三元醇型双固化聚氨酯丙烯酸酯的合成及其固化膜性能研究

以聚己内酯三元醇、异佛尔酮二异氰酸酯和羟基丙烯酸酯为原料,合成了一种新型聚氨酯丙烯酸酯。该树脂含有C C双键和未封闭的—NCO基团,可同时进行光固化和热固化反应。研究了不同双键含量对体系成膜性能的影响。结果表明,随着双键含量的上升,体系光固化后的摆杆硬度变大,耐溶剂性、玻璃化转变温度、铅笔硬度提高,但是柔韧性下降。同时发现,后期的热固化对体系的硬度和热性能有补强的作用,但是会在一定程度上导致涂膜的柔韧性下降。     

Synthesis and properties of UV-curable waterborne urethane modified acrylic coatings with varying vinyl content

It has been an effective method to improve the metal protective performance of UV-curable waterborne coatings by increasing the crosslinking degree. Hence, a series of UV-curable waterborne urethane modified acrylic (UV-WUA) coatings with different vinyl content were prepared. Firstly, a functional prepolymer containing carboxyl and hydroxyl groups was synthesized by free radical copolymerization (FRCP) using acrylic acid (AA), 2-hydroxyethyl acrylate (HEA), methyl methacrylate (MMA) and butyl acrylate (BA). Next, it was grafted with different amounts of semi-adduct of isophorone diisocyanate (IPDI) and HEA (IPDI-HEA), and finally neutralized and hydrated, obtaining UV-WUA dispersions which were then cured by UV to acquire cured films and coatings. Meanwhile, molecular structures, molecular weights, particle sizes, and Zeta potentials were characterized. Then, the heat resistance, mechanical performance, adhesion and the pencil hardness of the coatings were also investigated. Moreover, their protective performance was tested by electrochemical methods, and the surface morphology was analyzed by atomic force microscopy. The results showed that the coating had desirable comprehensive performance when vinyl content reached 0.86 mmol·g⁻¹.     

聚氨酯丙烯酸酯/SiO_2纳米杂化涂层的制备及其性能研究

采用不同相对分子质量的聚乙二醇(PEG-200、400、600)分别与六亚甲基二异氰酸酯(HDI)反应合成预聚体,再以此预聚体对纳米SiO2进行表面接枝改性,制备了聚氨酯改性纳米SiO2;将改性纳米SiO2分散到聚氨酯丙烯酸酯(PUA)中光固化制备了PUA/SiO2纳米杂化涂层。讨论了PEG相对分子质量对PUA/SiO2纳米杂化涂层的耐热性能和力学性能的影响,并以FT-IR、差示扫描量热法(DSC)等进行表征。结果表明,改性后的纳米SiO2粒子优化了PUA树脂的性能,且以PEG-400与HDI合成的预聚体来改性纳米SiO2用于制备的PUA/SiO2纳米杂化涂层具有较好的耐热性和抗冲击性。     

Photo‐curable highly water‐repellent nanocomposite coatings

Modification and use of natural products have gained a lot of interest in recent years due to their environmental friendliness and their availability from different sources. In this study, (castor oil)‐based photo‐curable highly hydrophobic coatings were prepared and characterized. Castor oil was first modified with 3‐isocyanatopropyltriethoxysilane and then hydrolyzed prior to the coating preparation. The resulting precursor was mixed with norbornyl acrylate and hexanediol diacrylate, and highly roughened hydrophobic coatings were prepared with the aid of fluorinated/nonfluorinated alkoxysilane coupling agents and hydrophobic fumed nanosilica particles. The coatings were applied on borofloat glass. The addition of fluorine and nanosilica showed a significant impact on the properties of the coatings. As the fluorine and nanosilica contents were increased in the formulations, flame retardancy and the contact angle values of the coatings increased. The surface roughness of the coatings increased with the addition of hydrophobic fumed nanosilica particles. Also, the relation between the surface energy and the contact angle values of the coatings was investigated. J. VINYL ADDIT. TECHNOL., 19:31–38, 2013. © 2013 Society of Plastics Engineers