Morphology,optical properties,and curing behavior of UV-curable acrylate-siloxane polymer blends

UV-curable organic-inorganic blends have captured lots of attention recently due to leveraging the positive features of polymer blending and radiation curing. However, the optical properties of such blends, including transparency, which is an important attribute in many applications, have not been sufficiently explored. In this study, a series of UV-Curable acrylate-siloxanes blends were prepared using different compositions and processing variables to obtain blends with promising transparency, and acceptable stability before and after curing. The variables include speed and time of mixing, siloxane functionality (-OH versus –CH₃), the monomer/oligomer ratio in the acrylate phase, and the amount of compatibilizer.The spectrophotometric results revealed that blends containing 100 wt% of acrylate monomer as the acrylate phase and 10 wt% of compatibilizer in the siloxane phase, demonstrated the highest transparency regardless of the siloxane functionality. SEM illustrated that a two-phase droplet-in-matrix morphology was formed containing dispersed siloxane particles in an acrylate matrix. The incorporation of compatibilizer significantly reduced the average size of the droplets and increased the uniformity of their distribution. Additionally, Photo-DSC, RT-ATR, AFM, and refractometry methods respectively showed that the addition of the siloxane phase to the acrylate matrix, regardless of its functionality, reduced the heat of reaction and CC conversion, while increased the surface roughness and refractive index. The developed UV-Curable acrylate-siloxane blends showed promising stability and transparency, and present a potential platform for PDLCs.     

Facile access to chiral 4-substituted chromanes through Rh-catalyzed asymmetric hydrogenation

Rh/ZhaoPhos-catalyzed asymmetric hydrogenation of a series of (E)-2-(chroman-4-ylidene)acetates was successfully developed to prepare various chiral 4-substituted chromanes with high yields and excellent enantioselectivities (up to 99% yield, 98% ee). Moreover, the gram-scale hydrogenation could be performed well in the presence of 0.02 mol% catalyst loading (TON = 5000), the hydrogenation product was easily converted to access other important compounds, which demonstrated the synthetic utility of this asymmetric catalytic methodology.     

Coherent control of narrow structures in absorption,transparency and dispersion by interference induced among the Rabi-split resonances

The evolution of nonlinear behaviour of electromagnetically induced absorption and transparency subject to coherent perturbation, is presented in a triply driven five-level atomic system. It has been shown that the coherence effects like absolute line narrowing, single or multiple transparencies, sharply varying dispersion and two opposite types of quantum switching can be efficiently controlled by interference induced among the Rabi-split resonances at various situations. As far as measurement induced subwavelength atom localization is concerned, this model can be very much useful in controlling single peak atom localization in subwavelength and sub-half-wavelength domain by three different ways.     

Synthesis of maleimide substituted polystyrene–silica hybrid utilizing michael addition reaction

The transparent polymer hybrids were prepared from polystyrene bearing pendant maleimide moieties (16%) and tetraethoxysilane (TEOS) using γ-aminopropyltriethoxysilane (γ-APS) as a crosslinking agent by an in situ sol–gel process by utilizing Michael-addition reaction. Maleimide substituted polystyrene was synthesized by a mild Friedel-Crafts reaction of polystyrene and N-chloromethylmaleimide. Fourier Transform Infrared (FTIR) spectral data confirms the occurrence of Michael-addition reaction between the pendant maleimide moieties of the styrene copolymer and γ-aminopropyltriethoxysilane. The percentage of maleimide substitution was calculated from ¹H NMR spectrum. The transparent hybrid shows high solvent resistance at the boiling point of Tetrahydrofuran (THF) since the polystyrene-substituted-maleimide (PS-s-MA) was covalently bonded with siloxane matrix. Thermal properties of the transparent hybrid materials were investigated by Differential scanning calorimeter (DSC) and Thermo gravimetric analysis (TGA) in order to ascertain their glass transition temperature (Tg) and thermal stability behaviour. Morphology and transparency of the organic–inorganic hybrids were confirmed by Scanning electron microscopy (SEM) and optical images. The homogeneity of the polymer hybrids was also examined by nitrogen porosimetry studies.     

TC2理论中tc夸克的联合产生

在TC2理论框架下,计算了在高能正负电子对撞机(LC)上,TC2动力学对味改变中性流过程e⁺e^－→tc产生截面的修正和TC2理论预言的中性top–pionπ0t对该过程产生截面的贡献.计算结果表明:TC2理论对LC实验中tc夸克联合产生的贡献主要来自中性top-pion π0t.在TC2理论的绝大部分参数空间内,可达10^－2ph.若假设LC的积分亮度为500fb^－1,则每年可产生数千个tc事例.因此,将来的LC实验可作为检验TC2理论的重要工具.     

类电磁诱导透明效应在硅基微环谐振腔中的实现与优化

为在硅基光波导上实现类电磁诱导透明效应,设计并加工了基于绝缘体上硅的串联双环结构.通过300℃到1 200℃热氧化退火、缓冲刻蚀液湿法腐蚀以及1 000℃高温氮气退火等波导结构的后期处理,利用垂直光栅耦合的方式输入及输出信号,观测到了类电磁诱导透明效应.分析了两环间不同间距对类电磁诱导透明效应的影响,结果表明:工艺中单环Q值达到5.1×104,类电磁诱导透明效应透明峰的带宽约为500MHz.     

溶剂和添加剂对尼龙6鬃丝结构形态和道明性的脸响

针对增加鱼网丝的透明性,各国都进行了大量的工作。一种措施是在生产尼龙6鬃丝的过程中,用不同的溶剂代替水作凝固浴,例如四氯化碳,氢氧化钠的水溶液,己烷,白油等。水的影响已引起人们的重视。另一种措施是在纺丝时向尼龙6切片中加入某种添加剂,例如氯化钠、十八烷基胺、硬脂酸锌共同使用,N,N′-双十八烷基对苯酰     

SYNTHESIS OF MBS RESIN BASED ON MOLECULE DESIGN

The relationships between the properties of PVC-MBS polyblend and of the MBS multiphase structure and between the MBS structure and polymerization parameters are studied theoretically and experimentally. MBS resin synthesized from the molecule design principle is suitable to prepare PVC-MBS polyblend with good transparency and high impact strength.     

Design and Synthesis of Transparent Poly （acrylonitrile-butadiene-styrene） and Relationship Between Its Phase Construction and Transparency

IntroductionABS resins have been widely applied to the field ofengineering materials because of their excellent me-chanical,electrical,physical,and chemical proper-ties.Typically,ABS resins comprise a rigid copolymermatrix-phase dispersed in a graft copol…     

Recovering recyclable materials: Experimental analysis of CD-R laser processing

This paper examines the influence of operating parameters in diode laser processing of CD-Rs for the purpose of recovering two of the main constituents: the polycarbonate substrate and the silver reflective layer. The targets used in experimental tests were ‘silver’ CD-Rs. Four operating parameters were investigated during experimental tests on selected CD-Rs, namely transverse and rotating speed, output power, and focal length. CD-Rs were successfully treated by using sufficiently wide operating ranges, and in optimized process conditions. It took less than 4.7 s to treat a CD-R, that is, 0.3 s less than the fastest CD-R manufacturing time. The best process performance is expressed in terms of transparency index, and is achieved by using both higher scanning speed and best focus conditions in conjunction. Output power is not so influential, but in order to attain the most effectiveness CD-R laser processing, values that are too low must be avoided. The extent of treated, untreated, and burnt areas of CD-Rs after diode laser processing was defined and measured, from which the most appropriate processing windows were found, including the quality of the recycled materials. Experimental findings were then used to define and validate an analytical model of CD-R laser processing. Two different mechanisms operating at low and high process speeds were inferred, and lastly, several aspects concerning the industrial application of the technique are discussed at length.