Ethylene Vinyl Acetate Foam

Vinyl acetate-ethylene copolymer emulsion is a polymer emulsion made of vinyl acetate and ethylene as basic raw materials, referred to as VAE emulsion or EVA emulsion in English. Since its introduction in 1965, it has been widely used in adhesives, building materials, coatings, papermaking, fabric processing, tobacco, packaging and other fields due to its excellent adhesion, permanent flexibility, good acid and alkali resistance and other properties.   In order to improve the performance of VAE emulsion and expand its application range, a lot of fruitful modification research has been done to improve the water resistance, mechanical strength, heat resistance, adhesion, curing speed and other aspects of VAE emulsion. These modification studies are mainly focused on the following directions: additive method, copolymerization method, composite modification method and blending method. Among them, the blending method is a method of physically blending VAE emulsion with one or more polymer solutions or emulsions to form a multi-component system. The properties of the various components of the blending method can complement each other, thereby obtaining new materials with better performance or new properties, reducing costs while potentially expanding the application field of VAE emulsion, allowing VAE emulsion to play a greater application value.   Polymer solutions or polymer emulsions that are often blended with VAE emulsions include: rosin resin, phenolic resin, urea-formaldehyde resin, terpene resin, polyurethane emulsion, acrylic emulsion, styrene-acrylic emulsion, vinyl acetate emulsion, styrene-butadiene emulsion, etc. Since VAE emulsion has good miscibility with a variety of emulsions, blending is the simplest and most direct way to achieve complementary properties of the blended components and obtain new properties.   PVAc emulsion was used to modify VAE emulsion, and at the same time, thickening resin and additives were used to synthesize an adhesive suitable for bonding non-polar plastic materials. The addition of thickening resin significantly improved the bonding strength of the emulsion; the addition of acidic metal salt crosslinking agent improved the water resistance of the system without affecting the stability of the emulsion.   VAE emulsion was modified by blending pure acrylic emulsion, acetic acid acrylic emulsion, silicone acrylic emulsion, styrene acrylic emulsion and VAE emulsion to prepare adhesive. The results show that the VAE emulsion modified by acrylate emulsion has been greatly improved in bonding performance and peel strength. Among them, the adhesive obtained by using acetic acid acrylic emulsion to modify VAE emulsion has the best comprehensive performance, especially the most obvious improvement in high temperature adhesion.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com ElephChem Holding Limited, professional market expert in Polyvinyl Alcohol(PVA) and Vinyl Acetate–ethylene Copolymer Emulsion(VAE) with strong recognition and excellent plant facilities of international standards.  

Vinyl acetate-ethylene copolymer (VAE) emulsion is the abbreviation of vinyl acetate-ethylene copolymer emulsion. It is a polymer emulsion formed by copolymerizing vinyl acetate and ethylene monomers with other auxiliary materials through emulsion polymerization.   White latex is a water-soluble adhesive, a thermoplastic adhesive produced by polymerization of vinyl acetate monomer under the action of an initiator. Usually called white latex or PVAC emulsion for short, the chemical name is polyvinyl acetate adhesive, which is synthesized from acetic acid and ethylene to vinyl acetate, with the addition of titanium dioxide (low-grade ones add light calcium, talc, and other powders). It is then made by emulsion polymerization. A thick milky white liquid.   VAE emulsion has the advantages of permanent softness, water resistance, low temperature resistance, fast bonding speed, high bonding strength, and is safe and non-toxic. VAE emulsion is widely used in adhesives, exterior wall insulation, building waterproofing, coatings, composite packaging materials, building cement mortar modification, non-woven fabric manufacturing, paper coating and general adhesive for various polar and non-polar materials. Access and other fields.   The characteristics of white latex include normal temperature curing, fast curing, high bonding strength, good toughness and durability of the bonding layer and not easy to age. White latex is a widely used water-soluble adhesive. It is mainly used in wood bonding, construction industry, coatings, etc. It is also used in furniture assembly, surface repair, etc.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com ElephChem Holding Limited, professional market expert in Polyvinyl Alcohol(PVA) and Vinyl Acetate–ethylene Copolymer Emulsion(VAE) with strong recognition and excellent plant facilities of international standards.

VAE (ethylene-vinyl acetate copolymer) emulsion viscosity is an important quality indicator and has a significant impact on product mass transfer, heat transfer, fluid flow, emulsion stability and emulsion transportation. Monomer ratio, polymerization temperature, initiator, emulsifier system optimization, electrolyte additives, and storage conditions are all factors that affect the viscosity of VAE emulsion.   1. Monomer ratio The selection and proportion of monomers directly affect the viscosity and other properties of VAE emulsion. The ratio of ethylene to vinyl acetate (VAc) is particularly critical. Generally speaking, VAE emulsions with a VAc content of 70% to 95% have higher viscosity. Increased VAc content will increase the flexibility and elasticity of the emulsion, and will also increase the viscosity of the emulsion.   2.Polymerization temperature control Polymerization temperature is another important factor affecting the viscosity of VAE emulsion. Changes in temperature will affect the rate of free radical generation and the rate of polymerization. Generally speaking, within a suitable temperature range, an increase in temperature will speed up the polymerization reaction, causing the latex particles in the emulsion to grow rapidly, resulting in an increase in viscosity. However, too high a temperature may cause the emulsion to gel, affecting its quality and stability.   3.Initiator The amount and type of initiator have a significant impact on the viscosity of VAE emulsions. Initiators mainly affect the rate of polymerization. When the amount of initiator is large, the polymerization reaction is fast, the number of generated latex particles increases, and the viscosity of the emulsion increases. However, excessive initiator may cause the reaction to be too fast and difficult to control, resulting in reduced emulsion performance. Different types of initiators generate different types of free radicals during the reaction and have different effects on the viscosity of the emulsion.   4. Emulsifier system optimization The selection and dosage of emulsifier are crucial to the stability and viscosity of VAE emulsion. The main function of emulsifier is to reduce the surface tension of emulsion and promote monomer dispersion and emulsion formation. Appropriate emulsifier concentration and anionic/nonionic emulsifier ratio can improve the stability of the emulsion and also affect the viscosity of the emulsion. The degree of polymerization and alcoholysis of protective colloids such as PVA (polyvinyl alcohol) also significantly affect the viscosity of the emulsion. The higher the degree of polymerization of PVA, the greater the viscosity of the emulsion; the higher the degree of alcoholysis, the lower the viscosity of the emulsion.   5.Electrolyte additives The addition of electrolyte additives can affect the viscosity and stability of VAE emulsions. Some electrolyte additives can compress the electric double layer of latex particles and reduce the electrostatic repulsion between latex particles, thereby increasing the viscosity of the emulsion. However, excessive amounts of electrolyte additives may cause aggregation in the emulsion, affecting its performance.   The factors that affect the viscosity of VAE emulsions include reaction time and rate, PH value, storage conditions and stability. In actual production and application, these factors need to be reasonably adjusted according to specific needs and conditions to obtain VAE emulsion products with excellent performance.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com ElephChem Holding Limited, professional market expert in Polyvinyl Alcohol(PVA) and Vinyl Acetate–ethylene Copolymer Emulsion(VAE) with strong recognition and excellent plant facilities of international standards.