News Details
Acrylic polyurethane dispersion (PUA) coating crosslinking agent
2017-5-11 17:54:28
Acrylic polyurethane dispersion (PUA) coating crosslinking agent. Acrylic polyurethane dispersion (PUA) with acrylic polymer modified polyurethane, due to the introduction of acrylic polymer, forming a core-shell structure, greatly improving the dispersion film hardness, solved the low temperature, the contradiction of the film and film hardness and has good adhesion, abrasion resistance, good elasticity, high impact strength, feel good characteristics.
Due to the good performance balance and versatility of PUA, it has been applied in water-based coating, adhesive, fabric treating agent, leather coating agent.
Waterborne polyurethane synthesis is often used when dihydroxy methyl propionate such strong hydrophilic compounds, the aggregation of the dispersion of more for a linear structure of the polymer, so the strength of the membrane are often poor, low water resistance, solvent resistance is poor.
In order to overcome these shortcomings, it is a good method to improve the molecular structure by using crosslinking method. Crosslinks can be divided into two types: the interlinking of the molecules and the crosslinking agent, which is often a bi-component system and is not very convenient to use. So there's been a lot of interest in the internal crosslinking method, and there's been a lot of research involved in this.
For example, the graft copolymerization of poly (acrylate and polyurethane molecular connections, the polyurethane molecular stated, the polyacrylate molecular stated, carboxyl in the process of dry film and epoxy crosslinking, and the introduction of ketone carbonyl/crosslinking hydrazide method, etc. It is an interesting question whether these crosslinks can be combined in a variety of ways.
This paper discussed the multiple crosslinking methods applied to the synthesis of acrylic modified polyurethane, the possibility of preparing PUA some, scope of application of crosslinking agent and matters needing attention. This dispersible body can be used as the base material of water-borne wood coating.
Crosslinking methods and mechanisms. The pu-pa copolymerization. The PUA dispersion is microscopically in the form of a polyacrylate (PA) hard core, which is a dispersed body of the shell of polyurethane (PU). In the film-forming process through the fusion of external soft shell to form a whole film, glass transition temperature of soft shell can be done is low (usually less than at room temperature), it overcomes the polyacrylate film at low temperature the disadvantages of poor get complete membrane. The internal PA hardcore can guarantee that the film has a good hardness, thereby avoiding the return viscosity of the membrane and improving the adhesion ability of the coating.
Chinese name: Diethyl toluene diamine(DETDA)
Diethyltoluenediamine Uses:
The product is identical to Ethancure 100 and Lonza DETDA 80, DETDA is very effective polyurethane elastomer chain extender; also be used as polyurethane and epoxy resin curing agent, epoxy resin of an antioxidant, industrial oils and lubricants . In addition, also as intermediates in organic synthesis.Especially for the RIM (reaction injection molding), is important in the field of spray polyurea chain extender species. Also can be used for casting polyurethane elastomer (CPU) and a curing agent, epoxy curing agent, epoxy resin of antioxidants, lubricants and industrial oils other antioxidants.
The mechanism of the PU and PA molecules is completely different. The PU relies on hydroxyl and isocyanates, and the PA is a double bond compound that is polymerized by free radicals. The non-coherence of the two reactions can affect the performance of the final products, such as water resistant, solvent-resistant and low mechanical strength.
If you combine the molecules of two polymers, it's good for performance. During the preparation of polyurethane (PU) to join the hydroxyl compounds containing double bonds, for example, (methyl) acrylic hydroxyl ethyl ester, (methyl), hydroxypropyl acrylate, etc., made of PU can participate in the polymerization of acrylates, can put the PU and PA molecules together, thereby improving the performance of the film forming matter.
Reaction first is the preparation of polyurethane pre polymers with double bond, reoccupy vinyl monomer and the free radical addition polymerization, which ties the two different types of large molecules.
Polyurethane internal crosslinking. Introduce three faculties PU synthetic degree of hydroxyl component, such as trimethylolpropane (TMP), glycerol, 1,2,6 - has three glycol, etc., to realize part of intramolecular crosslinking, the single, two-component solvent PU products, coatings, adhesives, leather finishing agent and fabric treatment agent, etc.) in a wide range of applications.
It turns out that the introduction of crosslinking agent has a significant effect on improving product performance. In the case of acrylic modified polyurethane dispersion system, it is also possible to add the appropriate tri-functional hydroxy compounds in the PU synthesis stage to allow the early local precrosslinking of the molecules.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Diethyl toluene diamine(DETDA) http://www.yaruichem.com
Due to the good performance balance and versatility of PUA, it has been applied in water-based coating, adhesive, fabric treating agent, leather coating agent.
Waterborne polyurethane synthesis is often used when dihydroxy methyl propionate such strong hydrophilic compounds, the aggregation of the dispersion of more for a linear structure of the polymer, so the strength of the membrane are often poor, low water resistance, solvent resistance is poor.
In order to overcome these shortcomings, it is a good method to improve the molecular structure by using crosslinking method. Crosslinks can be divided into two types: the interlinking of the molecules and the crosslinking agent, which is often a bi-component system and is not very convenient to use. So there's been a lot of interest in the internal crosslinking method, and there's been a lot of research involved in this.
For example, the graft copolymerization of poly (acrylate and polyurethane molecular connections, the polyurethane molecular stated, the polyacrylate molecular stated, carboxyl in the process of dry film and epoxy crosslinking, and the introduction of ketone carbonyl/crosslinking hydrazide method, etc. It is an interesting question whether these crosslinks can be combined in a variety of ways.
This paper discussed the multiple crosslinking methods applied to the synthesis of acrylic modified polyurethane, the possibility of preparing PUA some, scope of application of crosslinking agent and matters needing attention. This dispersible body can be used as the base material of water-borne wood coating.
Crosslinking methods and mechanisms. The pu-pa copolymerization. The PUA dispersion is microscopically in the form of a polyacrylate (PA) hard core, which is a dispersed body of the shell of polyurethane (PU). In the film-forming process through the fusion of external soft shell to form a whole film, glass transition temperature of soft shell can be done is low (usually less than at room temperature), it overcomes the polyacrylate film at low temperature the disadvantages of poor get complete membrane. The internal PA hardcore can guarantee that the film has a good hardness, thereby avoiding the return viscosity of the membrane and improving the adhesion ability of the coating.
Chinese name: Diethyl toluene diamine(DETDA)
Diethyltoluenediamine Uses:
The product is identical to Ethancure 100 and Lonza DETDA 80, DETDA is very effective polyurethane elastomer chain extender; also be used as polyurethane and epoxy resin curing agent, epoxy resin of an antioxidant, industrial oils and lubricants . In addition, also as intermediates in organic synthesis.Especially for the RIM (reaction injection molding), is important in the field of spray polyurea chain extender species. Also can be used for casting polyurethane elastomer (CPU) and a curing agent, epoxy curing agent, epoxy resin of antioxidants, lubricants and industrial oils other antioxidants.
The mechanism of the PU and PA molecules is completely different. The PU relies on hydroxyl and isocyanates, and the PA is a double bond compound that is polymerized by free radicals. The non-coherence of the two reactions can affect the performance of the final products, such as water resistant, solvent-resistant and low mechanical strength.
If you combine the molecules of two polymers, it's good for performance. During the preparation of polyurethane (PU) to join the hydroxyl compounds containing double bonds, for example, (methyl) acrylic hydroxyl ethyl ester, (methyl), hydroxypropyl acrylate, etc., made of PU can participate in the polymerization of acrylates, can put the PU and PA molecules together, thereby improving the performance of the film forming matter.
Reaction first is the preparation of polyurethane pre polymers with double bond, reoccupy vinyl monomer and the free radical addition polymerization, which ties the two different types of large molecules.
Polyurethane internal crosslinking. Introduce three faculties PU synthetic degree of hydroxyl component, such as trimethylolpropane (TMP), glycerol, 1,2,6 - has three glycol, etc., to realize part of intramolecular crosslinking, the single, two-component solvent PU products, coatings, adhesives, leather finishing agent and fabric treatment agent, etc.) in a wide range of applications.
It turns out that the introduction of crosslinking agent has a significant effect on improving product performance. In the case of acrylic modified polyurethane dispersion system, it is also possible to add the appropriate tri-functional hydroxy compounds in the PU synthesis stage to allow the early local precrosslinking of the molecules.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Diethyl toluene diamine(DETDA) http://www.yaruichem.com
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