Preparation Of Poly-¦Á-ethyl Cyanoacrylate And Poly (ethyl Methacrylate), Characterization And Density Functional Theory Study

Preparation of polymer and study on its performance are hot spots concerned by materials science today. This paper mainly uses anionic polymerization to compound poly (ethyl methacrylate) and poly (ethyl a-cyanoacrylates), and characterize their performances. Moreover applying theoretical calculation into polymer system and using the density functional theory, study the reactants and the transition state of ethyl acrylate and its derivative with initiator on the reaction potential energy level, molecular geometry, electronic structure, energy, spectrum and thermodynamic property. Systematically studying influence of solvating effect, consequently realize the whole microcosmic description on the anionic polymerization path. Main contents are as follows:Using anionic polymerization, compound poly (ethyl methacrylate) and poly (ethyl a-cyanoacrylates) with narrow molecular weight distribution, study reaction mechanism and polymerization conditions, and discuss effect of temperature, steric hindrance of initiator, additive and solvent on molecular weight and its distribution. By means of Fourier transform infrared spectrum (FTIR), hydrogen nuclear magnetic resonance spectrum (1HNMR), scanning electron microscope, gel penetration chromatographic analysis (GPC) and differential scanning calorimetry (DSC), characterize the performances of compounded products of poly (ethyl methacrylate) and poly (ethyl a-cyanoacrylates), determine degradation percent in different pH solution, and consequently study the relation between structure and performance and forecast its applied prospect.Using the density functional theory, study geometric configuration on entirely optimized gas phase of ethyl acrylate and its derivative on the level of B3LY/6-311G*. By means of theoretic method on self-consistent reaction field (SCRF), study the relation among geometry, electric charge, dipole moment and energy of ethyl acrylate and its derivative in liquid phase. Comparing with results of gas phase, reveal the effect of solvents with different dielectric constants on ethyl acrylate and its derivative.Utilizing search technique for transition state with low potential barrier in Gaussion98 program, successfully find the transition state of ethyl acrylate and its derivative in the process of anionic polymerization. Calculate geometric structure, dipole moment and energy of transition state of anionic polymerization on ethyl acrylate, ethyl methacrylate and ethyl a-cyanoacrylates by using self-consistent field theory. Study the characteristics and corresponding properties of polymerization in solvents withdifferent dielectric constants, as well as charge distribution of transition state and transfer situation of charge during anionic polymerization. Via calculating systematic energy of anionic polymerization on ethyl acrylate and its derivative in solvents with different dielectric constants, gain activation energy of this initiation reaction.The research reports calculated IR spectrum of ethyl acrylate and its derivative on the level of B3LYP/6-311G*, as well as its transition state, and analyzes and identifys. Discussing the effect of solvents with different dielectric constants on IR spectrum, and comparing with 'HNMR and IR spectrum of compounded products of poly (ethyl methacrylate) and poly (ethyl a-cyanoacrylates), the result indicates, calculated IR spectrum on the level of B3LYP/6-311G* basically (not correcting) accord with experiment result, proves vibration analysis research of this theory is reliable, and is important to design of compounding high polymer.By means of the density functional theory DFT-B3LYP, calculate thermodynamic parameters such as isobaric thermal capacity Cp, standard entropy STo. and standardenthalpy HoT of reactants of ethyl acrylate, ethyl methacrylate and ethyla-cyanoacrylates within temperature range of (200~600)K and in gas phase of transition state, on the basis of vibration analysis and by statistical thermodynamics method. According to absolute reaction rate theory, gain anionic initiation rate...