环氧丙烯酸酯涂料的UV固化研究

采用傅里叶红外光谱,对以γ-缩水甘油醚氧丙基三甲氧基硅烷与丙烯酸为主要原料所制备的低黏度环氧丙烯酸酯涂料的UV固化过程进行了定量分析。结果表明,环氧丙烯酸酯的UV固化反应是打开CC双键的自由基聚合反应,双键转化率的高低决定了涂膜的固化程度与硬度。随着固化时间的延长,环氧丙烯酸酯中CC双键的交联反应先快后慢,所得涂膜的硬度相应增加;固化时间为96s时,CC双键的转化率达到最高,涂膜的铅笔硬度为H;进一步延长固化时间,涂膜的硬度不再增加。     

巯基-双键点击反应制备光固化红光转光膜及其性能

本研究将不同含量的稀土转光剂与含巯基和双键单体共混制备了光固化树脂,然后经巯基-双键或双键-双键点击反应制备了两种农用转光膜,通过荧光光谱、UV光谱、SEM、拉伸性能测试等对转光膜的结构与性能进行表征。研究结果表明,添加0.5%(质量分数)稀土转光剂的转光膜能将波长为353 nm的紫外光转换为波长为613 nm和617 nm的红光,且该转光膜具有良好的透光性能和力学性能,拉伸强度达到12.72 MPa,在农业大棚、玻璃温室等方面具有良好的应用前景。     

紫外光固化含氟聚氨酯弹性涂层的制备及性能研究

以异佛尔酮二异氰酸酯(IPDI)、端羟基聚丁二烯(HTPB)、1,4-丁二醇(BDO)和丙烯酸羟乙酯(HEA)为主要原料制备了双键封端的聚氨酯树脂,通过红外、核磁对聚氨酯的结构进行了表征,结果表明合成的聚氨酯结构明确;对合成的聚氨酯树脂进行氟改性,当氟单体用量增加到8%时,聚氨酯弹性涂层的铅笔硬度由2B提高到HB,光泽度由67.5°提高到78.2°,接触角由85.4°上升到108.3°;利用巯基-烯反应速率快、氧阻聚效应小的特点,在体系中加入多官能的巯基化合物,结果表明聚氨酯涂层的表干时间由32s缩短到12s,光泽度由78.2°提高到86.8°,铅笔硬度由HB提高到了H。     

聚乙二醇二丙烯酸酯齐聚物的合成及其红外激光固化性能研究

使用3种方法合成了具有不同分子量的聚乙二醇二丙烯酸酯（PEGDA）齐聚物,包括：聚乙二醇（PEG）与丙烯酸反应,聚乙二醇与丙烯酰氯反应,聚乙二醇钠与丙烯酰氯反应,并在此基础上对3种合成方法进行比较。研究了聚乙二醇二丙烯酸酯齐聚物的红外激光固化反应,利用红外分析测定双键转化率,发现随着齐聚物分子量增大,激光固化后的双键转化率有所上升。     

双环戊二烯/蒎烯共聚合研究

研究了以三配钨酚(WCl_6)做主催化剂,一氯二乙基铝(Et_2AlCl)做助催化剂,蒎烯(Pinene)为共聚单体与双环戊二烯(DCPD)进行共聚,采用反应注射成型工艺制备出了聚双环戊二烯/蒎烯(PDCPD/Pinene)材料。并采用红外光谱、扫描电镜和热重等表征手段对复合材料的结构及性能进行了表征。结果表明:所制备出聚双环戊二烯/蒎烯复合材料,共聚物经溶剂抽提后质量不变,且红外光谱分析显示存在DCPD加成后的特征吸收峰;热失重分析显示共聚合物仅有一个分解温度。同时考察了蒎烯用量对聚双环戊二烯/蒎烯复合材料力学性能及转化率的影响。材料拉伸和冲击性能在α-蒎烯和_β-蒎烯含量均为0.5%时达到最佳,与聚双环戊二烯材料相比,拉伸性能分别提高了52.78%和53.89%;其冲击性能也分别提高了23.98%和18.86%;以α-蒎烯和_β-蒎烯混合物(其中α-蒎烯占70%,β-蒎烯占30%)与DCPD共聚,其共聚的拉伸强度和冲击强度分别提高了43.89%和15.4%。     

紫外光固化聚氨酯丙烯酸酯粘结剂的优化设计EI北大核心CSCD

采用红外光谱对聚氨酯丙烯酸酯(PUA)涂料的紫外固化过程进行定量分析;测试了不同配方和固化条件下涂膜的摆杆硬度、柔韧性和抗冲击性;考察了γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)对粘结剂附着力的影响,并对其作用机制进行了分析。结果表明,固化过程中C=C双键发生聚合,其转化率反映了涂膜的固化程度;增大光强、减少稀释剂用量和延长固化时间均有利于提高双键转化率和摆杆硬度;随着光引发剂浓度的增加,双键转化率先增后减;增大二官能PUA比例能够提高涂膜柔韧性和抗冲击性;KH570能够改善涂膜附着力,加入量越大改善效果越明显,且静置对附着力有很大影响;其作用机制是KH570分子中的双键与丙烯酸双键发生聚合,羟基与基底间形成氢键作用。     

紫外光固化聚氨酯丙烯酸酯粘结剂的优化设计

采用红外光谱对聚氨酯丙烯酸酯(PUA)涂料的紫外固化过程进行定量分析;测试了不同配方和固化条件下涂膜的摆杆硬度、柔韧性和抗冲击性;考察了γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH570)对粘结剂附着力的影响,并对其作用机制进行了分析。结果表明,固化过程中C=C双键发生聚合,其转化率反映了涂膜的固化程度;增大光强、减少稀释剂用量和延长固化时间均有利于提高双键转化率和摆杆硬度;随着光引发剂浓度的增加,双键转化率先增后减;增大二官能PUA比例能够提高涂膜柔韧性和抗冲击性;KH570能够改善涂膜附着力,加入量越大改善效果越明显,且静置对附着力有很大影响;其作用机制是KH570分子中的双键与丙烯酸双键发生聚合,羟基与基底间形成氢键作用。     

超支化拓扑高分子“点击化学”合成的新进展

"点击化学"具有高效和选择性强等优点,有利于"裁剪"合成具有丰富拓扑结构的超支化高分子。综述了利用炔基-叠氮1,3-偶极环加成反应、巯基-烯烃加成反应、胺/双键加成反应三种"点击化学"控制合成超支化高分子拓扑结构新进展。     

多官能度丙烯酸酯的合成及光固化性能

以双季戊四醇及乙氧基化双季戊四醇与丙烯酸反应合成含双季戊四醇五丙烯酸酯与六丙烯酸酯的混合物及乙氧基化双季戊四醇六丙烯酸酯,五丙烯酸酯的羟基进一步与异氰酸酯反应合成十官能度聚氨酯改性丙烯酸酯,用傅里叶变换红外光谱、核磁共振波谱对其结构进行表征。用FT-IR光谱研究了所得丙烯酸酯在低光能密度的光照下双键转化率与双键密度间关系,结果表明,双键转化率随双键密度的增大呈现先升高后降低的趋势。在丙烯酸酯单元含量相近时,丙烯酸酯间的距离越大,交联点的分布越均匀,在光固化速度及固化膜硬度下降不多时膜的韧性得到提高。     

支化苯乙烯-丙烯腈共聚物合成与结构表征

以α-溴代异丁酸叔丁酯(t-BBiB)为引发剂,二乙烯苯(DVB)为支化单体,经原子转移自由基聚合(ATRP)合成支化苯乙烯/丙烯腈共聚物。用核磁共振(~1H-NMR)、凝胶渗透色谱-多角激光散射(GPC-MALLS)和黏度测试方法对聚合反应过程和聚合物进行表征和分析。结果表明,反应初期生成带有悬垂双键的初级链,在单体转化率达到40%后悬垂双键参加反应生成支化聚合物;随着单体转化率的提高,支化结构更为完善,聚合产物Zimm支化因子变小;同一聚合物样品中,分子质量较高的组分具有相对较高的支化程度,表现出相对更小的Zimm支化因子。     

Effect of highly dispersible zirconia nanoparticles on the properties of UV-curable poly(urethane-acrylate) coatings

Highly crystalline and dispersible zirconia nanoparticles, ex situ synthesized from a solvothermal reaction of zirconium(IV) isopropoxide isopropanol complex in benzyl alcohol, were functionalized with 3-(trimethoxysilyl)propyl methacrylate and blended with UV-curable urethane-acrylate formulations to fabricate poly(urethane-acrylate)/zirconia (PUA/ZrO₂) nanocomposite coatings. A critical ZrO₂ concentration of 20 wt% was observed for the evolutions of both the structure and properties of the nanocomposites as a function of ZrO₂ content. Below the critical concentration, completely transparent nanocomposite film was obtained and the nanocomposites exhibited increasing final carbon–carbon double bond conversion, refractive index, hardness, elastic modulus, and thermal stability as ZrO₂ content increased. However, serious agglomeration of ZrO₂ nanoparticles occurred at 25 wt% of ZrO₂, which decreased final conversion, transparency and hardness, and thermal stability of the nanocomposite film. These results clearly reveal that the performance of UV-curable nanocomposites is strongly dependent on the dispersion of nanoparticles.     

基于准连续域束缚态介质超表面的光微流折射率传感研究

准连续域束缚态(Quasi-BIC)是超表面中一种特殊共振模,具有极高的品质因子,可以极大地提高光与物质的相互作用,在荧光增强、纳米激光、光传感以及非线性光学等领域均有重要应用。本文基于我们前期对quasi-BIC产生的理论,研究quasi-BIC介质超表面在折射率传感方面的应用。本文给出了传感系统的基本结构,利用电子束光刻技术结合注塑工艺完成了样品光流控结构的制备,并初步测试性能。研究结果表明,得益于产生quasi-BIC的新方法,该超表面具有两个高Q值quasi-BIC共振峰(1.523 µm和1.570 µm,品质因子分别为3069和4071)。以四种折射率溶液(n分别为1.450/1.462/1.470/1.480)为样品的测试实验表明,两个共振峰均能完成折射率检测,灵敏度S分别为452 nm/RIU、428 nm/RIU,性能评价指标FOM分别为376.7、372,优于现有文献;共振波长和折射率之间线性度良好,展现了quasi-BIC超表面在折射率传感中的应用潜力。

     

Synthesis of a novel tertiary amine containing urethane dimethacrylate monomer (UDMTA) and its application in dental resin

A novel tertiary amine containing urethane dimethacrylate monomer UDMTA was synthesized with the aim of replacing Bis-GMA as one component of dental restorative materials. The structure of UDMTA was confirmed by FT-IR and ¹H-NMR spectra. UDMTA was incorporated into Bis-GMA/TEGDMA (50 wt%/50 wt%) resin system to replace Bis-GMA partly and totally. Double bond conversion, polymerization volumetric shrinkage, water sorption and solubility, flexural strength and modulus of UDMTA containing resin formulations were studied with neat Bis-GMA/TEGDMA resin formulation as a reference. Results showed that UDMTA could be used as a coinitiator in photocurable dental resin, UDMTA containing resin had higher double bond conversion and lower polymerization shrinkage than that of Bis-GMA/TEGDMA resin, and the UDMTA containing copolymer had higher flexural strength and flexural modulus than Bis-GMA/TEGDMA copolymer. When UDMTA was used to replace more than 25 wt% of Bis-GMA, the obtained copolymer had higher water sorption and solubility. The optimized resin composition is by replacing 25 wt% of Bis-GMA in Bis-GMA/TEGDMA (50/50 by wt%), for the prepared resin had the best comprehensive properties.     

Optical and mechanical characterization of evaporated SiO(2) layers. Long-term evolution

Numerous characterizations were performed on 120-nm thick evaporated SiO(2) layers in order to understand how their features change as a function of deposition conditions and time. Density decreases with increasing deposition pressure. It governs all the layer properties (refractive index, hardness, and stress). In situ stress measurements show that stress can be divided into intrinsic and water-induced components, respectively linked to local density (outside the pores) and porosity. Intrinsic stress increase with decreasing pressure is explained by a diminution of the Si-O-Si bond angle (IR measurements). Long-term evolution is characterized by stress relaxation related to Si-O-Si strained bond hydrolysis.     

Acetonitrile covalent adduct chemical ionization mass spectrometry for double bond localization in non-methylene-interrupted polyene fatty acid methyl esters

Covalent adduct chemical ionization (CACI) using a product of acetonitrile self-reaction, (1-methyleneimino)-1-ethenylium (MIE; CH2=C=N+=CH2), has been investigated as a method for localizing double bonds in a series of 16 non-methylene-interrupted fatty acid methyl esters (NMI-FAME) of polyenes with three and more double bonds. As with polyunsaturated homoallylic (methylene-interrupted) FAME and conjugated dienes, MIE (m/z 54) reacts across double bonds to yield molecular ions 54 mass units above the parent analyte. [M + 54]+ ions of several 20- and 22-carbon FAME that include one double bond in the C2-C3 position separated by two to five methylene units from a three, four, or five C homoallylic system dissociated according to rules for the homoallylic system, with an additional fragment corresponding to cleavage between the lone double bond and the carboxyl group and defining the position of the lone double bond. Triene FAME with both methylene and ethylene interruption yielded characteristic fragments distinguishable from homoallylic trienes. Fragmentation of fully conjugated trienes in the MS-1 spectra yields ratios of [M + 54]+/[M + 54 - 32]+ (loss of methanol) near unity, which distinguishes them from homoallylic FAME having a ratio of 8 or more; collisionally activated dissociation of [M + 54]+ yields a series of ions, including some rearrangement products, indicative of double bond position. Unlike conjugated dienes, fully conjugated triene diagnostic ion signal ratios did not follow any pattern based on double bond geometry. Partially conjugated trienes behave similarly to monoenes and conjugated dienes, yielding [M + 54]+/[M + 54 - 32]+ of 2-3 and, permitting them to be assigned as partially conjugated FAME using the MS-1 spectrum. They yield unique MS/MS spectra with weaker but assignable fragment ions, along with a diagnostic fragment that locates the lone double bond and permits 6,10,12-octatrienoate to be distinguished from 6,8,12-octatrienoate. The presence of a triple bond did not affect fragment formation in a methylene-interrupted yne-ene but did change fragments in a conjugated yne-ene. These data extend the principle of double bond localization by acetonitrile CACI-MS/MS to double bond structure in complex FAME found in nature.     

氮掺杂氟化非晶碳薄膜光学性质的研究

用射频等离子体增强化学气相沉积(RF-PECVD)法制备氮掺杂氟化非晶碳(a-C:F:N)薄膜.用紫外-可见分光光谱仪、椭偏仪、傅立叶变换红外光谱仪对薄膜进行了检测.结果表明:随源气体中氮气含量的增加,光学带隙先减小后升高,折射率变化情况与之相反.在其它条件相同的情况下,升高沉积温度使得薄膜的光学带隙和折射率降低.光学带隙的大小与sp2键含量密切相关,sp2键浓度越大,薄膜的光学带隙越小.     

松香树脂酸合成新材料的研究进展

综述了松香树脂酸合成新材料的最新研究进展,分别详细介绍了松香树脂酸基于羧基的改性、共轭双键的改性、羧基和芳环的共改性以及羧基和共轭双键的共改性及其衍生物的应用情况,并展望了该领域发展趋势及前景。     

High-sensitivity double-parameter sensor based on the fibre-tip Fabry–Pérot interferometer

We have proposed an ultra-compact double polymer-capped Fabry–Pérot interferometer (FPI), which could be used for simultaneously measuring refractive index (RI) and temperature with low cross sensitivity. The designed and fabricated FPIs have double polymer layers which were fabricated by step-curing ultraviolet photoresist (SU-8) and polydimethylsiloxane on the end face of a traditional single-mode fibre. Three samples were fabricated with different Fabry–Pérot cavity lengths. Experimental results show that the double polymer structure has higher temperature and RI sensitivities than single-layer structure. About 689.68 pm/°C (based on the wavelength shift) in the temperature range of 20–75 °C and ?147.04 dB/RIU (based on peak intensity measurement) in the RI range of 1.335–1.355 were measured, respectively. Moreover, the compact structure, high temperature sensitivity and low cross-sensitivity of the FPI make it suitable for integration such as biomedical and microfluidic sensor probe.     

Photosensitizer–Gold Nanorod Composite for Targeted Multimodal Therapy

In this work, a DNA inter‐strand replacement strategy for therapeutic activity is successfully designed for multimodal therapy. In this multimodal therapy, chlorin e6 (Ce6) photosensitizer molecules are used for photodynamic therapy (PDT), while aptamer‐AuNRs, are used for selective binding to target cancer cells and for photothermal therapy (PTT) with near infrared laser irradiation. Aptamer Sgc8, which specifically targets leukemia T cells, is conjugated to an AuNR by a thiol‐Au covalent bond and then hybridized with a Ce6‐labeled photosensitizer/reporter to form a DNA double helix. When target cancer cells are absent, Ce6 is quenched and shows no PDT effect. However, when target cancer cells are present, the aptamer changes structure to release Ce6 to produce singlet oxygen for PDT upon light irradiation. Importantly, by combining photosensitizer and photothermal agents, PTT/PDT dual therapy supplies a more effective therapeutic outcome than either therapeutic modality alone.     

端丙烯酸酯基超支化聚酯/聚氨酯丙烯酸酯体系的紫外光固化行为及性能

利用红外光谱(FT-IR)法研究了端丙烯酸酯基超支化聚酯(VHBP)/聚氨酯丙烯酸酯(PUA)体系紫外光固化反应,并研究了不同代数及含量VHBP对涂层性能的影响。结果表明,纯PUA达到最终双键转化率所需的时间最短,VHBP代数和含量高的体系时间较长。在PUA中加入VHBP后涂层硬度大幅提高,具有良好的综合性能,优于传统的PUA/环氧丙烯酸酯体系。随着VHBP含量的增加,涂层的硬度逐渐增大,耐冲击性和附着力有所降低。在相同VHBP含量时,硬度随代数的增加而逐渐降低。