Synthesis Basic Emulsion For Water-Based Damping Coatings

Recent years,with gradual emphasis on noise pollution,shock-absorbing damping materials are becoming popular used in industrial production and daily life.Although commonly used asphalt damping coatings have good damping property and low price.However,when heated,they not only produce VOC components that are harmful to the environment,but also volatilize certain substances that are harmful to the human body,which have a certain negative impact on environmental protection and living health,the water-based damping coating that combines environmental protection and excellent performance has been favored by many industries.The development and research of new waterborne damping coatings have both theoretical and practical significances.The main components of waterborne damping coatings include basic emulsions,fillers and flame retardants.The damping performance mainly comes from the performance of the matrix polymer.In this article,we carried out the following works on damping base emulsions and made basic research for preparing high-performance damping coatings.1.A series of styrene-acrylic emulsions were prepared by random copolymerization.By changing the ratio of soft and hard monomers and the amount of emulsifier,the effects of the above plans on the properties of the emulsions and the mechanical properties,the water absorption as well as the damping properties of the films were studied.In the DMA curves,the material is considered to have a damping effect when tan δ ≥ 0.3.The study found that by changing the butyl acrylate / styrene(BA/St)ratios,the glass transition temperature(Tg)can be changed.With the increase of the St component,the effective damping temperature range shifts to high temperature,but the temperature range width does not change significantly,and the change in the amount of emulsifier does not affect the damping performance.A series of styrene-acrylic emulsions were prepared by graft polymerization method.The ratio of soft and hard monomers was changed.It was found that the styrene-acrylic emulsions obtained by conventional graft polymerization would show a damping performance faultage in the DMA curve and could not meet the requirement of the wide temperature range.2.A series of monomer-alternating multilayered core-shell styrene-acrylic emulsions were prepared by semi-continuous seeded emulsion polymerization and the multilayer structure in which soft and hard monomers are alternately grafted were realized.As a result,it is found that the damping performance of the core-shell emulsion films,still have damping faultage and could not meet the requirement of the damping.Furthermore,we had designed the particles with monomer ladder multilayered core-shell structure,and the structural design of the styrene-acrylic emulsions with increasing proportion of the soft monomer in each shell from the inside to the outside.The results showed that the monomer ladder multi-layered core-shell emulsion films have the best effect of keeping the damping temperature region intact and a wide temperature range.The effective damping temperature range is above 100 °C.