Alkyl Methacrylate Monomers Research Articles

Studies on a New Series of Cross-Linked Polymer Electrolytes for a Lithium Secondary Battery

We have studied cross-linked polymer electrolytes prepared by polymerization of polyethylene glycol dimethacrylate (PEGDMA) and alkyl methacrylate monomer (MMA, EMA, and BMA) in the presence of liquid electrolyte [1.3 M carbonate-diethyl carbonate or 1.3 M carbonate-propylene carbonate (EC-PC)]. Flexibility and ionic conductivity of the electrolyte matrix improved as the monomer content is increased and the alkyl chain of the monomer becomes shorter. As the alkyl chain length becomes long, e.g., BMA, the polymer matrix does not appear to form a homogeneous phase with a highly polar electrolyte, e.g., resulting in reduced ionic conductivity. The polymer electrolyte containing 50 wt % MMA forms homogeneous films with good mechanical properties and gives high ionic conductivity of at room temperature. We have also studied the electrical performance and cycling performance of a Li/polymer electrolyte/ solid-state cell employing PEGDMA and alkyl methacrylate monomer-based polymer electrolyte. © 2001 The Electrochemical Society. All rights reserved.

Poly(methacrylates) bearing dendritic blocks

Alkyl methacrylate monomers with three kinds of dendritic fragments as alkyl groups, two kinds of Frechet-type and a new type containing multi-aryl ether linkage, were prepared. These macromonomers were radically polymerized with 2,2'-azobisisobutyronitrile (AIBN) as the initiator. The concentration of monomers has great influence on the degree of polymerization. High degrees of polymerization are obtained at high concentration of monomers even for those monomers with dendritic side groups in the second generation. The activation energy of thermal degradation of polymers was calculated by the integral (Ozawa) method. It reveals that the stability of the polymers is greatly improved with increasing generation number of dendritic wedges as side blocks. The functionality of the chain ends of the dendritic fragments also influences considerably the thermal properties of the polymers. The glass transition temperature decreases with increase of the size of the side groups.

Poly(methacrylates) bearing dendritic blocks

Alkyl methacrylate monomers with three kinds of dendritic fragments as alkyl groups, two kinds of Fréchet-type and a new type containing multi-aryl ether linkage, were prepared. These macromonomers were radically polymerized with 2,2′-azobisisobutyronitrile (AIBN) as the initiator. The concentration of monomers has great influence on the degree of polymerization. High degrees of polymerization are obtained at high concentration of monomers even for those monomers with dendritic side groups in the second generation. The activation energy of thermal degradation of polymers was calculated by the integral (Ozawa) method. It reveals that the stability of the polymers is greatly improved with increasing generation number of dendritic wedges as side blocks. The functionality of the chain ends of the dendritic fragments also influences considerably the thermal properties of the polymers. The glass transition temperature decreases with increase of the size of the side groups.

Preparation of high purity, anionic polymerization grade alkyl methacrylate monomers

A method has been developed which provides very pure alkyl methacrylate monomers for anionic polymerization. This method takes advantage of the chemistry of trialkylaluminum compounds-their reactivity with alcohols and moisture, and their complex formation with methacrylic esters which facilitates titration of impurities. When coupled with previously known polymerization techniques, this purification methodology allows for both the synthesis of narrow distribution poly(alkyl methacrylates) of controlled and predictable molecular weight and for the utilization of a wide variety of methacrylate monomers. The procedure described herein should be equally applicable to group transfer polymerization.

Study of oil soluble polymers as drag reducers

AbstractThis investigation was undertaken to find the most effective material which would reduce the friction coefficient in turbulent flow when added in small quantities to oil pipelines. For this purpose, a series of oil‐soluble polymers, namely homopolymers and copolymers of alkyl methacrylates, alkyl acrylates, and alkyl styrenes were synthesized. Emulsion polymerization techniques were used. Commercially available alkyl methacrylate and alkyl acrylate monomers were used in the synthesis. Monomeric alkyl styrenes were synthesized and structures established prior to polymerization. Intrinsic viscosities were measured and viscosity average molecular weights were calculated for several of the homopolymers synthesized in this study. Reduction of factional drag and resistance to shear degradation were measured by pumping a solution of the polymer in a hydrocarbon solvent through a pipe and recording the pressure drop across the pipe. Drag‐reducing properties of several of the polymers were correlated in terms of their viscosity average molecular weights. Drag reduction of poly (isodecyl methacrylate) was studied in various hydrocarbon solvents. Drag‐reducing behavior of polymers prepared in this study exhibited a strong dependence on molecular weight; increasing the molecular weight increased the drag reduction for a given polymer concentration and pipe size. Several of these polymers were found to be superior to commercially available polyisobutylene as drag reducers, especially in terms of shear stability.

Analysis of Polymethacrylate Viscosity Index Improvers by Pyrolysis-Gas Chromatography

Polymethacrylate viscosity index (V.I.) improvers were analysed by pyrolysis-gas chromatographic technique, and constituent monomer of them were quantitatively determined. Polymethacrylates were decomposed in the sample vaporizer of ordinary gas chromatograph without using particular pyrolyzer, so that the condensation of alkylmethacrylate monomers having high boiling point was prevented. The optimum decomposition temperature for quantitative analysis was 400°C, where any secondary decomposition of monomers didn't occur.By this technique, some of commercial polymethacrylate V.I. improvers were analysed, and it was clarified that these are the multi-component copolymer of C1∼C18 alkyl methacrylate monomers. It was also found that V.I. improving performance of these polymethacrylates tends to vary with the content of C1∼C4 alkylmethacrylate in the polymer.

Vinyl polymerization. LXXIX. Effect of the alkyl group on the radical polymerization of alkyl methacrylates

AbstractThe effect of the alkyl group on the rates of polymerization of alkyl methacrylates initiated by α,α′‐azobisisobutyronitrile in benzene at 60°C. has been investigated. The rate of polymerization increased with increasing length of the alkyl group. This has already been attributed to the increased steric effect of the alkyl group in the termination process. In the present study, it was proved that the viscosities of alkyl methacrylate monomers increased with increasing length of the alkyl group, and that overall polymerization rate constants were inversely proportional to the viscosities. Accordingly, the above result might be explained by an increase in the contribution of the diffusioncontrolled termination with increasing length of the alkyl group in alkyl methacrylate.