Chlorosulfonated Rubber Modified Acrylate Water Emulsion And Its Related Molecular Simulation

In this paper,acrylic acid is the functional monomer,butyl acrylate is the soft monomer,methyl methacrylate and styrene are the hard monomers,and chlorosulfonated polyethylene(CSM)is the modified substance.Chlorosulfonated polyethylene modified acrylate emulsion was obtained by pre-emulsion copolymerization.In order to explore the interaction between chlorosulfonated polyethylene and acrylate in water emulsion and its cross-linking modification mechanism from the atomic and molecular perspectives,this paper studied the influence of chlorosulfonated polyethylene with different chlorine contents on the properties of acrylate rubber by using computer molecular simulation method.Including the study of diffusion coefficient(MSD),glass transition temperature(Tg),young's modulus(E),shear modulus(G),bulk modulus(K),the free volume fraction(FFV),cohesive energy density(CED),the influence of the interaction energy and polar groups,etc.The details are as follows:1.The properties of the water emulsion prepared by three steps of monomer preemulsification,seed emulsion preparation and polymerization were analyzed.The test results showed that:(1)In water emulsion,the stability,adhesion,water resistance,hardness,etc.all comply with the national standard QB/T 2223-1996;(2)After modification using CSM,which accounts for 4.5%of the total monomers,the particle size is the smallest and the better storage stability.(3)With the addition of CSM,the film-forming adhesive strength increased and then decreased,and reached the maximum at the addition of 4.5%;(4)According to TGA analysis,it is found that the addition of CSM can improve the thermal stability of acrylate emulsion,and reached the maximum at the addition of 4.5%;(5)The elongation at break of100°C high temperature cured film is proportional to the amount of CSM added,and the tensile strength is inversely proportional to the amount of CSM added,indicating that the addition of CSM helps to improve the heat resistance of acrylate emulsion;(6)In the modified water emulsion,as the amount of CSM increases,the self-corrosion potential moves forward,the impedance values increase,indicating that CSM can improve the corrosion resistance of acrylate water emulsion.2.Molecular dynamics simulation of heat resistance and mechanical properties of chlorosulfonated polyethylene modified acrylate adhesives with different chlorine content.In this paper,CSM models with different chlorine content were constructed to simulate the molecular dynamics of modified acrylate adhesive(BMA).The results:(1)With the increase of chlorine content,T_g,Young's modulus(E),shear modulus(G),bulk modulus(K),cohesive energy density(CED)first increase and then decrease,reaching a maximum value when the chlorine content is 26 wt.%.(2)The free volume fraction(FFV)of the system increases continuously with the increase of temperature.When the temperature is?300 K,the addition of CSM makes the increase of FFV of the BMA system decrease significantly;(3)Through the analysis of the interaction energy and the influence of polar groups,when the chlorine content is 26 wt.%,CSM has the best modification effect on acrylate water emulsion.3.All-atom and coarse-grained simulations were carried out on lignocellulosic modified chlorosulfonated polyethylene system.In the experiment,it was found that CSM has a greater impact on the performance of the emulsion.In order to obtain water emulsion with better performance,it is considered to further modify the CSM with lignocellulose to improve the performance of the CSM.The results:(1)With the increase of lignocellulose(LCC)content,T_g has been increasing,indicating that LCC can improve the high temperature resistance of CSM.E,G,K,CED,increase first and then decrease and reach the maximum value when lignocellulose accounts for 66%of the total system(66LCSM),the mechanical properties are the best.FFV shows a trend of decreasing first and then increasing,reaching a minimum value at 66LCSM;(2)After the coarse-grained simulation of the system,the density curve and radial distribution analysis are performed,the results were consistent with the results of all-atom simulation.4.Molecular dynamics simulation of interactions of poly(amidoamine)with sodium octadecyl sulfate at the water/octane interface.Through experiments,it is found that the emulsification effect is very important for the success of the experiment.In order to further explore the emulsification properties of petroleum sulfonate from the molecular level.This article uses MARTINI force field coarse-grain molecular dynamic simulations of interactions of poly(amidoamine)with sodium octadecyl sulfate at the water/octane interface.The influence of the addition of PAMAM at the oil-water interface on the properties of SOS was analyzed by density curve,interface thickness,order parameters,interfacial tension,compression modulus and radial distribution function.The results:(1)The interface thickness and order parameters of the system are proportional to the SOS interface coverage.With the increase of the SOS interface coverage,the arrangement of SOS molecules on the interface is more upright and orderly,and the interface tension decreases;(2)The addition of PAMAM can further increase the interface thickness and order parameters and further reduce the interface tension;(3)The strong molecular force between PAMAM molecule and SOS molecule can be seen from RDF peak.