光敏有机硅防粘剂的合成与性能

以含氢硅油和甲基丙烯酸烯丙酯为原料,通过硅氢加成法制备了具有紫外光固化性能的聚二甲基硅氧烷丙烯酸酯防粘剂预聚体.研究了反应温度、催化剂浓度及溶剂对反应的影响,确定了最佳反应条件:反应温度为60-70 ℃,以三苯基膦氯化铑为催化剂,加入量为原料总重量的0.04%.利用红外光谱法表征了预聚物的结构,并考察了其感光性能及表面性能.预聚体的感度可达56.9 mJ/cm2,其固化膜具有较低的表面能(γds(H2O)=32.49 mN/m).     

甲基丙烯酸酯类含硅有机单体的制备及其光固化

以甲基丙烯酸羟乙酯、γ-甲基丙烯酰氧基丙基三甲氧基硅烷为原料,在乙醇钠催化下进行酯化反应,合成了可以进行紫外光固化的多官能度甲基丙烯酸酯类含硅有机单体混合物(MAE-Si-OCH_3),并通过傅里叶红外光谱和核磁共振氢谱(~1H-NMR)对其结构进行了表征。通过~1H-NMR确定了甲基丙烯酸酯基团,含硅基团和甲氧基的比例关系。以2,4,6-三甲基苯甲酰基-二苯基氧化膦为光引发剂,考察了MAE-Si-OCH_3在405 nm LED光源下的自由基光固化行为。测试了MAE-Si-OCH_3的耐酸耐碱性和硬度。研究发现,所制备的甲基丙烯酸酯类含硅有机单体可以有效地进行自由基光固化,并且具有较好的耐酸碱性和一定的硬度。     

2－烷基蒽醌引发环氧丙烯酸酯光固化行为的研究

研究了在没有其它活化剂存在条件下，采用２－烷基蒽醌直接引发环氧丙烯酸酯体系的光交联反应。应用光谱方法和重量法测定了反应体系在光固化过程中双键含量、光交联密度、凝胶转化率和固化膜硬度的变化情况。实验结果表明，２－烷基蒽醌直接引发环氧丙烯酸酯类的光固化反应，具有很好的引发效率，可以和安息香双甲醚与流杂蒽酮等光引发剂相比拟，并具有价格便宜、光固化可在空气条件下操作等优点，另外对反应体系的引发剂浓度、组分配比的影响以及对不同类型环氧丙烯酸酯反应体系的引发效果均进行了讨论。     

光敏有机硅聚氨酯丙烯酸酯预聚体光聚合性能的研究

采用实时红外法（Real time infrared spectrum,RTIR）详细研究了光引发剂及活性单体对光敏有机硅聚氨酯丙烯酸酯（Polysiloxane urethane acrylate,PSUA）体系的光聚合性能的影响。研究发现,断裂型光引发剂的引发效率要高于夺氢型的光引发剂的引发效率,其中Irgaeure 1700引发体系的聚合速率最快。光引发剂最佳用量为0．5％～1％。体系的双键转化率随单体官能度的增加而降低。含单体HEA和IBOA的感光体系的双键转化率最大,基本完全聚合;而含TPGDA和HDDA的体系的双键转化率大约在90％～95％之间;含TMPTA的体系的双键转化率只有80％左右。含不同活性单体体系的双键转化速率的大小顺序为：TPGDA≈HDDA〉HEA〉TMPTA〉IBOA,体系的双键转化率和双键转化速率都随着单体含量的增加而减小。     

含硅光固化材料的性能研究

研究了体系组成对光固化有机硅聚氨酯丙烯酸酯(Polysiloxane isophorone urethane acrylate,PSIUA)体系的耐水性、体积收缩、硬度、附着力、耐溶剂性及机械性能的影响.研究发现,含羟基及醚键的活性单体会使体系吸水率上升;随着体系交联度增加,吸水率下降.PSIUA体系体积收缩率随PSIUA含量的增加而下降,所研究的PSIUA体系的体积收缩率均小于10%.加入三官能团单体和具有刚性结构、交联度较大的的环氧丙烯酸酯有利于提高体系的硬度.加入适量的含羟基的活性单体及环氧丙烯酸酯可以提高PSIUA光固化膜的附着力.测得PSIUA体系的玻璃化转变温度为246.0℃.     

有机硅环氧树脂及其复合材料的光固化研究

通过研究光引发剂的种类、用量、光照时间和光敏剂等对树脂光固化后凝胶率的影响,确定了ES-06有机硅环氧树脂光固化的工艺条件,在质量分数分别为5%的二苯基碘鎓六氟磷酸盐光引发剂和5.5%的多元醇链转移剂作用下,光照10 min后紫外光开环聚合产物的凝胶率可达80%.利用湿法手工铺叠工艺和光固化技术,制备了玻璃布/有机硅环氧树脂复合材料,测试并分析比较了有机硅环氧和双酚A环氧复合材料的力学性能.结果表明,光固化有机硅环氧树脂基复合材料层板的拉伸强度和层间剪切强度较优,分别为158.5 MPa和9.9MPa,而两者的弯曲性能和拉伸模量相当.     

紫外辐射共聚制备含环氧基团的多孔聚合物及其在固定化酶上的应用

以乙二醇二甲基丙烯酸酯(EDMA)为交联剂,甲基丙烯酸缩水甘油酯(GMA)为功能单体,聚乙二醇200(PEG 200)为致孔剂,采用紫外辐射共聚一步法制备了含有环氧基团的多孔聚合物。光电子能谱(SEM)分析表明,紫外辐射共聚法制备的聚合物表面含有环氧基团;扫描电镜结果表明:共聚过程中致孔剂的存在,能够在聚合物内形成多孔结构。采用共价结合法固定辣根过氧化酶(HRP),多孔结构有效增加了辣根过氧化酶的结合量,平均每克共聚物最高可以结合29.6 mg辣根过氧化酶。     

含药水凝胶膜的制备及其药物释放规律的研究

对辐照前、后两种庆大霉素进行体外抑菌实验,研究辐照对庆大霉素效价的影响。应用辐射交联技术,分别于辐照前、后加入药物,制备含药水凝胶膜,研究其药物体外释放规律。结果表明,37．5kGy电子束对庆大霉素的效价无影响。辐照前、后掺加药物的水凝胶膜分别在12h、8h内药物快速释放达高峰,而后缓慢释放,持续到第5天,其释放规律符合Higuchi方程,释药原理属骨架型扩散释放机制。相比较而言,辐照前掺入药物的水凝胶膜药物释放更为完全。     

UV curing of nanoparticle reinforced acrylates

To improve the surface hardness of radiation cured acrylate coatings, both silica nanoparticles and alumina particles with a few microns in size have been embedded into acrylate formulations. Regular mixing of nanoparticles into acrylate formulations, however, leads to highly viscous solutions inappropriate for coating procedures. The incompatibility of inorganic fillers and organic polymers can be avoided by surface modification of nanoparticles using trialkoxysilanes, which provide an interface between the two dissimilar materials. Nanoparticles modified by methacryloxypropyltrimethoxysilane (MEMO) and vinyltrimethoxysilane (VTMO), both having polymerisation-active groups, may be crosslinked with the acrylate resin. UV curing of the nanocomposites revealed an unexpected lower reactivity of the vinyl groups of VTMO modified silica compared to MEMO grafted on silica. For VTMO modification, DFT calculations showed a decrease of Mulliken atomic charge for the olefinic carbons pointing to a lower reactivity. For UV cured nano/microhybrid composites, a significant improvement of abrasion resistance was obtained.     

异海松酸UV固化反应条件研究

研究了异海松酸为单体进行紫外光固化反应的影响因素,采用红外光谱法对双键转化率进行了表征和分析。采用凝胶色谱分析（GPC）、差示扫描量热分析（DSC）和热重分析（TO）等手段对固化膜的性能进行了表征。结果表明：固化过程中双键转化率随光照时间的增加而增加,随引发剂添加量增加先上升后下降;相对固化速率随引发剂用量、光照强度的增加及光照距离的减小而增加。     

水性丙烯酸树脂的合成和UV固化研究

合成了一种新型的、可射线固化的水性丙烯酸树脂,采用该树脂和各种辅助成分配制成水性涂料。研究了在合成过程中异氰酸酯基含量（ＮＣＯ％）的变化以及该树脂的水稀释曲线。同时研究了辐照时间、距离,光引发剂的种类,光敏助剂以及活性稀释剂对交联程度的影响,得到了性能优良的涂膜。     

颜料/树脂界面状态对UV固化效率的影响

本工作对颜料的表面改性及其对紫外光(UV)固化效率的影响进行了研究。研究发现,除了通常认为的颜料对UV的吸收以及散射会造成UV固化效率下降外,颜料表面与树脂的界面区域残存有空气成分也可能是造成彩色光固化涂层固化速度下降的另一个重要原因。电子能谱研究结果表明,三乙醇胺改性的艳佳丽蓝颜料不仅使得颜料/树脂界面的空气成分大幅减少,而且颜料与树脂的结合处改性前后的碳、氮、氧的组成成分、结合能都发生了明显的变化,存在着明显的界面耦联现象。颜料改性后,固化速度比未改性前有明显提高(例如,膜厚为125μm的涂料通过三乙醇胺对蓝色颜料改性,固化时间从45s减少到14s)。显然这与颜料/树脂界面的状态有关,说明通过颜料的改性来促进UV固化是可行的。研究结果对光固化彩色涂料的研究开发乃至光固化体系填料的使用等都具有积极意义。     

叔胺结构对有机硅改性聚丙烯酸酯树脂UV固化的影响

UV-radiation curing has become a well-accepted technology because of its distinct advantages mainly as environmental benign, efficiency, less energy consumption and mild curing condition. The free radical photopolymerizations have been based mainly on acrylate systems, which polymerize rapidly and can be adjusted with ease to modify materials with different properties for different applications. The primary limiting factor of the approaches, however, is that the reactions would be inhibited by oxygen. A main method to tackle the problem is to add tertiary amine. Nevertheless, this causes new problems in the curing products, which turn yellow easily and their deposited period becomes short.In this work we have synthesized silicone modified polyacrylate (SPA) resins from bis[3-(trimethoxysilyl)propyl]amine (A1170) and polyethylene glycol diacrylate (SR-344) through Michael addition (Fig. 1). Without adding any extra tertiary amine, the structure of the obtained prepolymers could effectively solve the problem of oxygen inhibition.The DPC curves characterizing the UV curing behavior of the prepolymers are shown in Fig.2. With the SPA, the curing reaction in ambient atmosphere reached the maximum reaction rate at almost the same time as in N2, and the reaction rate in air is a little higher than in N2. The conversion of SPA in air is also a little higher than in N2. All these may be explained as follows. Tertiary amine can suppress the oxygen inhibition and produce more radicals. Tertiary amine may offer hydrogen to peroxide free radical produced in the oxygen inhibition process, the latter further decompose into alkyl radicals and hydroxide radicals.However, chain transfer and radicals terminations tend to occur, which made the rate reduced quiekly at later stages of the curing [1].     

Synthesis of amidoxime polymer gel to extract uranium compound from seawater by UV radiation curing

A new amidoxime polymer gel for uranium extraction from seawater was successfully prepared by photoinitiated crosslinking polymerization. It involves UV-induced radical polymerization of acrylonitrile (AN) and methacrylic acid (MAA) monomers with crosslinking agent and photoinitiator: an alternative synthesis pathway to gamma radiation. Characteristic peaks of Fourier transform infrared spectroscopy (FTIR) indicated that nitrile group was completely converted into amidoxime group. Eight hours of 60 W UV curing was enough for polymer gel formation. For the 4 to 1 ratio of AN to MAA, crosslinking agent concentration of 1 g/100 mL-monomers and photoinitiator content of 60 mL/100 mL-monomer, maximum uranium adsorption capacity of 17.02 mg/g adsorbent in seawater was achieved for sample spiked with 10 ppm uranium. For seawater sample spiked with 2,245 ppm uranium, the adsorption capacity reached 432.41 mg/g adsorbent. The amidoxime polymer gel could be regenerated for at least eight cycles while retaining about 50% of the uranium uptake capacity. Thus, the present amidoxime polymer adsorbent is a high-efficiency seawater uranium recovery agent for both high and low uranium concentrations.     

紫外光氧化法制备水溶性富勒醇

富勒烯因其特殊的结构在生物学中具有潜在的重要应用价值,而其不溶于水阻碍了其在相关领域的进一步应用。制备水溶性的富勒烯衍生物的方法被证实是一种可行的途径。本文采用波长为254nm的紫外光作为照射源,通过照射水溶液中的H2O2使其分解产生·OH自由基,并与富勒烯分子发生加成反应,成功制备了富勒醇。对制备的富勒醇进行了纯化、分析和表征。实验结果表明,合成的富勒醇分子结构式为C60(OH)26。紫外光氧化法制备水溶性富勒醇是一种简单可行的新方法,为由富勒烯制备富勒醇提供了新的借鉴。     

马来酸酐紫外辐照接枝高密度聚乙烯的制备及表征

采用紫外辐照技术制备了高密度聚乙烯-马来酸酐接枝物（HDPE—g—MAH）,并用红外光谱对接枝物进行了表征。研究了紫外光辐照时间、单体及引发剂浓度、第二单体苯乙烯（St）等因素对接枝率及凝胶含量的影响。结果显示,辐照时间为30s时,接枝效果最佳。马来酸酐（Maleic anhydride,MAH）用量的增加使接枝率不断上升,而接枝效率则在MAH含量为5．2％时达到最大值,之后开始下降。光引发剂二苯甲酮（Benzophenone,BP）的用量对接枝率及凝胶含量有重要影响,其用量为0．5％时接枝效果较好;St的加入使接枝物的凝胶含量显著降低。