PVA Glue

Polyvinyl alcohol (PVA) is a widely used synthetic material. PVA ability to dissolve in water and break down naturally makes it a good choice for packaging films. The main production methods for PVA film are aqueous solution coating and melt blow molding. PVA is hard to shape with heat because it melts at a higher temperature than it decomposes. This is due to the strong links between its molecules and its crystal structure. Therefore, the most important factor in the processing of PVA film is the selection of appropriate additives.   1. Effect of Plasticizer Amount on Tensile Strength, Tear Strength, and Elongation at Break of Polyvinyl Alcohol Film As shown in Figure 1, film ability to resist breaking lessens as more plasticizer is added. This suggests that plasticizers reduce how strong the film is. The plasticizer gel theory explains that when the plasticizer mixes with the resin, it loosens the points where the resin molecules connect. These connections have different strengths. The plasticizer pulls them apart and hides the forces that hold the polymer together. This reduces the secondary forces between the polymer macromolecules, increases the flexibility of the macromolecular chains, and accelerates the relaxation process. Tensile strength goes down as you add more plasticizer. As the amount of plasticizer is increased, the film becomes more flexible and stretches further before breaking. This suggests that plasticizers make the film more pliable. Plasticizers achieve this by weakening the attraction between the large molecules in the polymer. This increased flexibility and longer relaxation period lead to the film ability to stretch further. The data indicates that as more plasticizer is added, the film becomes easier to tear. This likely happens as the plasticizer reduces the film's surface energy and lessens the energy needed for both plastic flow and lasting deformation. These factors, in turn, contribute to the film's reduced resistance to tearing.   2. Effect of Crosslinker Amount on the Tensile Strength, Elongation at Break, and Tear Strength of PVA Film As shown in Figure 3, the film's tensile strength goes up gradually as the amount of crosslinker is increased, during which the elongation at break goes down gradually. When a certain point is reached, the film's tensile strength goes down gradually, while the elongation at break goes up gradually. At first, as more crosslinker is added, the number of working polymer chains goes up, intermolecular forces get stronger, and the polymer chains become less flexible. The ability of the large molecular chains to change shape and rearrange decreases while the chain relaxation is difficult. So, the tensile strength goes up, while the elongation at break goes down. Continuing the use of crosslinkers causes degradation and branching to increase gradually, which decreases the number of working polymer chains, and increases the flexibility of the polymer chains. The ability of the large molecular chains to change shape and rearrange increases, while the chain relaxation becomes easier. As a result, the tensile strength starts to go down again, while the elongation at break goes back up. As shown in Figure 4, the tear strength of the film changes with the amount of crosslinker. At first, it goes up, but then it starts to go down. This happens because when crosslinking starts, more crosslinker helps the polymer network form. This makes the film's surface energy go up gradually. It then needs more energy to spread plastic flow and irreversible viscoelastic processes. Because of this, the film's tear strength gets better as crosslinking happens. But, if there is too much crosslinker with too much polymer broken down, and there are more branching reactions, the tear strength gets worse.   3. Conclusions When you add more plasticizer, PVA film becomes less strong but stretches and tears more easily. When you add more crosslinker, film strength and resistance to tearing improve at first, but then weaken, while its ability to stretch keeps getting better.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

The full name of PVB is polyvinyl butyral, or PVB resin for short. It contains a lot of hydroxyl (OH) groups, which can produce bridging reactions with some thermosetting resins to improve chemical resistance and coating film hardness. PVB molecules contain long branched chains and have good flexibility, excellent transparency, strong adhesion, good light resistance, heat resistance, cold resistance, water resistance, film-forming properties, solubility, miscibility, high tensile strength and impact resistance, etc. It is widely used in the fields of manufacturing laminated safety glass, coatings, adhesives, ceramic film decals, vacuum aluminum foil paper, electrical materials, fiberglass products, fabric treatment agents and engineering plastics. It is a synthetic resin material with broad development and utilization prospects. There are three main synthesis methods for producing PVB(such as Butvar B-98 & PVB WWW-A-20) in the industry: one-step method, dissolution method and precipitation method. The following will introduce these three process methods and their advantages and disadvantages in the production process one by one.   The one-step method refers to a generation process in which the hydrolysis of polyvinyl acetate (PVAC) and the acetal reaction of the generated PVB are carried out simultaneously. It is represented by the production process of Solutia Company (the chemical division of Monsanto Company was split to form Solutia Company, which has now been acquired by Eastman Company). Vinyl acetate is bulk polymerized to form a methanol solution of polyvinyl acetate, and HCI is added for alcoholysis. The PVA generated by alcoholysis is suspended in a mixed solvent of ethanol and ethyl acetate, and butyraldehyde and HCI are added for acetal reaction. At the reflux temperature, react for 8 to 10 hours. As the reaction proceeds,  Polyvinyl Alcohol (PVA) is completely dissolved and a uniform PVB solution is finally formed. Then add alkali to adjust the pH to 6. After reaching the specified acetal rate, it precipitates in water. After washing, neutralizing and drying, the finished PVB product can be obtained.   The dissolution method is to make PVA into a methanol suspension, add HCI and butyraldehyde to perform a condensation reaction. As the reaction proceeds, PVA gradually dissolves to form a uniform solution. After reaching the specified acetal ratio, it precipitates in water. After washing, neutralizing and drying, the finished PVB product can be obtained. The acetal rate of the PVB resin produced by this method can reach more than 86%, and the condensation distribution is uniform.   The precipitation method requires first dissolving PVA in water (85-90°C), then filtering the solution, pressing it into an acetal kettle, adding hydrochloric acid and butyraldehyde, and adding butyraldehyde in two batches to start homogeneous condensation. When the reaction reaches a certain level, PVB particles are precipitated from the solution and suspended in the mother liquor, which is a heterogeneous condensation reaction. When the condensation is completed, the material is put into a water washing kettle, washed with water, and alkali is added for stabilization, then filtered and dried to obtain powdered PVB.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Redispersible emulsion powder is a modified emulsion powder obtained by spray drying of a binary or ternary copolymer of vinyl acetate and tertiary vinyl carbonate -VeoVa or ethylene or acrylic ester, which has good redispersibility and is re-dispersed into emulsion when it is in contact with water, and its chemical properties are exactly the same as the initial emulsion. After mixing with the water in the mortar, it emulsifies and disperses in the water to form a stable polymerization emulsion. After dispersing in water, the water evaporates, forming a polymer film in the mortar after drying, improving the performance of the mortar. Different dispersible latex powders have different effects on the dry mortar. 1. Improve the impact resistance, durability and wear resistance of mortar The rubber powder particles fill the cavity of the mortar, the densification of the mortar is increased, and the wear resistance is improved. Under the action of external forces will produce relaxation and not be destroyed. The polymer film can exist in the mortar system for a long time.   2. Improve the bonding strength and cohesion of mortar As an organic binder, dispersible emulsion powders provide high tensile strength and bonding strength on different substrates. It plays a very important role in the adhesion between mortar and organic materials (molded plates, extruded plates) and smooth surface substrates. The film-forming polymer rubber powder is distributed in the whole mortar system as a reinforcing material to increase the cohesion of the mortar.   3. Improve the mortar's weatherability, freeze-thaw resistance and prevent mortar crackingThe RDP emulsion powder is a thermoplastic resin adhesive powder with good flexibility, which can make the mortar cope with the external cold and hot environment changes and effectively prevent the mortar from cracking due to the change in temperature difference.   4. Improve the hydrophobicity of mortar and reduce water absorptionThe RDP emulsion powder forms a film in the mortar cavity and surface, and the polymer resin film will not disperse twice after encountering water, preventing the invasion of water and improving the impermeability. Enhanced dispersible adhesive powder with hydrophobic effect has better hydrophobic effect.   5. Improve the bending strength and flexural strength of mortar The polymer film formed by dispersible emulsion powder has good flexibility. The film is formed in the gap and surface of cement mortar particles to form a flexible connection, so that the brittle cement mortar becomes elastic. The mortar added with dispersible emulsion powder has much better tensile and flexural properties than ordinary mortar.   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.

ElephChem Polyvinyl alcohol (PVA) is a versatile polymer with a wide range of applications due to its unique combination of properties, including water solubility, film-forming ability, and adhesion. Here are some common applications of ElephChem Polyvinyl Alcohol:   1.Adhesives: ElephChem PVA is widely used in the formulation of water-based adhesives. It provides excellent adhesion to various surfaces, making it suitable for woodworking, paper bonding, and packaging applications.   2.Paper Industry: ElephChem PVA is used as a surface sizing agent in the paper industry. It improves the surface properties of paper, such as smoothness and printability.   3.Textile Industry: In the textile industry, ElephChem PVA is used as a sizing agent to add strength and flexibility to fibers during the weaving process. It is also employed in the production of warp yarns.   4.Emulsion Polymerization: ElephChem PVA is used in emulsion polymerization processes to stabilize and control the particle size of latex polymers. It serves as a protective colloid in the synthesis of latex dispersions.   5.Packaging Films: ElephChem PVA is utilized in the production of water-soluble packaging films. These films are environmentally friendly and find applications in single-dose packaging for detergents, agrochemicals, and other products.   6.Textile Sizing: ElephChem PVA is used as a sizing agent for warp yarns in the textile industry. It imparts strength and lubrication during the weaving process.   7.Construction Industry: ElephChem PVA is incorporated into cement-based formulations as a cement modifier. It enhances the adhesion and workability of cementitious materials, such as mortar and concrete.   8.Release Agents:  ElephChem PVA is used as a release agent in the production of molded objects, such as rubber and plastic components. It prevents adhesion of the molded product to the mold surface.   9.Medical Applications: ElephChem PVA is used in the medical field for applications such as the production of hydrogel-based wound dressings and controlled drug delivery systems.   10.Photographic Films: ElephChem PVA is used as a protective colloid in the manufacturing of photographic emulsions. It contributes to the stability and dispersibility of silver halide crystals.   11.Coatings and Paints: ElephChem PVA is employed as a binder in water-based coatings and paints. It enhances film formation, adhesion, and flexibility.   12.Water-Soluble Films: ElephChem PVA is used to produce water-soluble films for various applications, including packaging of detergents, dyes, and agrochemicals. These films dissolve in water, leaving no residue.   These applications showcase the versatility of polyvinyl alcohol across diverse industries. The specific grade and characteristics of ElephChem PVA can be tailored to meet the requirements of each application, making it a valuable polymer in the manufacturing sector.