Liquid crystal is a material which is between solid and liquid phase and commonly called mesophase. Blends of liquid crystal are of great interest because of their unique optical properties. Blending in this study using two monomers of liquid crystal were cholesteryl acrylate and methyl phenyl benzoyl acrylate. The polymerization process using uv curing techniques by irradiation UV ray and without irradiation UV ray. Polymerization of blending liquid crystal acrylate using initiator 2-hydroxy-2-methyl-1-phenylpropane. Based on peak at GPC curve of polymerization by irradiation UV ray, type of that polymer is copolymer. Therefore the polymerization without UV ray, type of that polymer is homopolymer. SEM images of liquid crystal acrylate polymer showed lamella chain models that are characteristic of a polymer chains. Type of polymer liquid crystal acrylate was the type of Side Chain Liquid Crystalline Polymers (SCLCPs). Therefore acrylate polymer liquid crystal in this research has semi-crystalline phase, which contained crystalline phase and amorphous phase on the XRD pattern. The results of FT-IR spectroscopic characterization of the two monomers showed a peak at the wave number of 1600.43 cm -1 and 1622.86 cm-1 which indicates a double bond (C=C) were obtained from acrylation. While the spectroscopy on the product blending the wave number of the peak regions is reduced that shows that carbon double bonds (C=C) in the acrylate group has polymerized. It also strengthened with a very sharp peak for CC functional groups on the wave number of 2855.15 cm-1. The results of this study indicate that the liquid crystal polymer acrylic polymerization results with radiation UV ray and without UV ray, respectively absorb light in the UV wavelength region 363 nm and 351 nm. 相似文献
Densities of the ternary system 1,4-dioxane + butyl acrylate + ethyl acrylate and its binary butyl acrylate + ethyl acrylate have been measured in the whole composition range, at 298.15 K and atmospheric pressure, using an Anton Paar DMA 5000 oscillating U-tube densimeter. The calculated excess molar volumes of the binary system are positive and were correlated with the Redlich–Kister equation and with a series of Legendre polynomials. Several models were used to correlate the ternary behavior from the excess molar volume data of their constituent binaries and were found equally good to fit the data. The best fit was based on a direct approach, without information on the component binary systems. 相似文献
Abstract Phenylacetylene (PA, M2) and methyl acrylate (Mi) copolymerization can be described by the simple terminal model having the parameters r1 = 0.67 and r2 = 0.11. 1H-NMR spectroscopy shows the predominant trans configuration of PA units, the high tendency of coisotactic alternating addition, and influence of temperature on the chain conformation. 相似文献
Acrylate–alkyd hybrid latex via miniemulsion polymerizations show promise as water‐borne coating systems. However, poor homogeneity of the particles caused by the immiscibility of the alkyd in polyacrylate limits monomer conversion and film formation. To resolve this problem, the hybrid miniemulsion polymerization of acrylate in the presence of linoleic acid and sunflower seed oil was carried out. Products were characterized by solvent extraction, dynamic light scattering, gel permeation chromatography (GPC), differential scanning calorimeter (DSC), and transmission electron microscopy (TEM). The results provide clear evidence that substituting a fatty acid or natural oil with smaller molecular size (weight) for a conventional alkyd improves the grafting efficiency, and enhances the homogeneity of the hybrid polymer particles in water‐borne latex systems.
The polymerization kinetics of n-lauryl acrylate have been investigated in ethyl acetate and n-heptane at 40°C. A high monomer order, 1.6(5), was found in both solvents. Corresponding initiator orders, determined using Azdn and lauroyl peroxide, were slightly less than the usual value of 0.5. Although the chain termination reaction is undoubtedly diffusion controlled from the start of polymerization, diffusion effects dependent on monomer concentration only partly account for the high monomer order. Other possible explanations based on primary radical termination, “cage-effects,” degradative chain transfer, and radical complexing are also not applicable. Contrary to observations with lower acrylate esters, autoacceleration effects do not occur in the high conversion polymerization of n-lauryl acrylate. Ths probably reflects the reduced importance of radical branching reactions with this monomer. 相似文献
Ternary monomer reactivity ratios of triisopropylsilyl acrylate (SiA), methyl methacrylate (MMA), and n‐butyl acrylate (BA), as common monomers in self‐polishing coatings (SPCs) binders are obtained using experimental data collected from free radical bulk polymerization at 70 °C. Different terpolymerizations at low and medium‐high conversions are performed at optimized feed compositions. Estimations are made using the error‐in‐variables model (EVM) framework, applying the recast form of the Alfrey–Goldfinger (AG) model and a direct numerical integration (DNI) approach to the collected data. Estimations from individual low and medium‐high conversion data are compared to those found with the combined data (full conversion range data). The highest certainty in point estimates are obtained with analysis of the full conversion range data. Furthermore, the reactivity ratios determined from the combined data fall between those found with analysis of individual low and medium‐high conversion data, another corroboration of reliable data collection. Reactivity ratios determined from analysis of the combined data (rSiA/MMA = 0.4185, rMMA/SiA = 1.3754, rSiA/BA = 0.8739, rBA/SiA = 0.5736, rBA/MMA = 0.3692, rMMA/BA = 1.7919) are used in the recast AG model to predict cumulative terpolymer composition as a function of conversion. The experimental data and model prediction show satisfactory agreement. 相似文献
A procedure was developed for the determination of polyethylene glycol monoester acrylate (PEGMA) and polyethylene glycol diester acrylate (PEGDA) by reversed-phase high performance liquid chromatographic (RP-HPLC) with UV detector. Sample was well separated on an SinoChrom ODS-BP (C-18) column (200 × 4.6 mm i.d., 5 μm) with mobile phases composed of acetonitrile-phosphate buffer solution (0.05 mol · L?1 pH = 6.86) in the ratio of 42:58 (v/v). The PEGMA and PEGDA were detected by UV detector at 205 nm, and quantitatively analyzed with an external standard of methyl acrylate. For PEGMA, the linear response ranged from 0.40 × 10?5 mol · L?1 to 2.00 × 10?3mol · L?1 (r2 > 0.999), the detection limit was 0.12 × 10?5 mol · L?1, the recovery rate was found to be 93.4%–99.7%. For PEGDA, the linear response ranged from 0.20 × 10?5 mol · L?1 to 1.00 × 10?3mol · L?1 (r2 > 0.999), the detection limit was 0.04 × 10?5 mol · L?1, the recovery rate was found to be 99.1% ~ 105.8%. This quantitative method can also be used in the HPLC analysis of other α,β-unsaturated esters. 相似文献
Polyurethane acrylate resins cured by two different ways, a thermal way and a photochemical way, are investigated by means of differential scanning calorimetry (DSC) and thermally stimulated depolarization currents (TSDC). Even if both curing methods lead to the same material from a chemical point of view, we show that important differences exist between the thermocured resin and the photocured resin in terms of molecular relaxation behaviour.This revised version was published online in November 2005 with corrections to the Cover Date. 相似文献
Abstract Copolymers of p-nitrobenzyl acrylate and methyl acrylate with different feed ratios are synthesized in ethyl methyl ketone using benzoyl peroxide as a free radical initiator at 70 ± 1°C. The copolymers were characterized by IR and 1H-NMR spectroscopic techniques. Copolymer compositions were determined by 1H-NMR analysis of the polymers. The monomer reactivity ratios were determined by the application of conventional linearization methods such as Fineman–Ross and Kelen–Tüdös. Gel permeation chromatography was used for determining the molecular weights Mn and Mw, and the polydispersity index. The intrinsic viscosities and the thermal properties of the homo- and copolymers are also discussed. 相似文献
β-Picolinium-p-chlorophenacylide initiates radical polymerization of methyl acrylate (MA) up to 19.5% conversion without gelation due to autoacceleration. The average rate of polymerization (Rp) increases as [ylide] is raised from 1.02 to 3.06 mmol/L, the order of reaction being 0.5 ± 0.02. However, at higher concentrations (>3.06 mmol/L), Rp decreases. The monomer exponent is 1.40 when benzene is used as diluent. The overall energy of activation is computed to be 28.8 kJ/mol. A polar solvent like dimethyl-sulfoxide and a radical scavenger like hydroquinone retard the reaction. The kinetic data and ESR studies indicate that the polymerization proceeds via a free-radical mechanism. Chain termination by degradative chain (initiator) transfer appears to be significant. 相似文献