News Details
Polyurethane foam is used chain extender
2017-2-26 17:42:00
Polyurethane foam is used chain extender, more varieties of glycol type chain extension agent, mainly has 1, 4 - butanediol, ethylene glycol, propylene glycol, a shrinkage diethylene glycol, neopentyl glycol, etc. The ternary alcohol compounds with glycerol, trimethylolpropane (TMP), etc.
In the synthesis of polyurethane foam, the most used is 1, 4 - butanediol. Polyurethane is A basic linear structure (A - B) x type block copolymer, the soft chain segment composed, polyethylene glycol macromolecular chain of hard segment is composed, diisocyanate and low molecular diol reaction and 1, 4 - butanediol has A moderate carbon - carbon chain length, can make the soft and hard chain segment produces micro zone to separation, carbamate hard chain segment crystalline better, even if have to MDI - 1, 4 butanediol hard chain can well orientation.
Crystallization and orientation arrangement makes it easier for between polymer molecular chain to form hydrogen, means that can produce good orderly crystal, crystal resistance effect and polymer chain segment of migration, finally show the polymer has excellent toughness and hardness.
Is given priority to with fatty alcohol kind of chain extender, the bubble in the products, is mainly used in high elastic resilient soft, semi-hard foam, rigid RIM and microporous elastomer products such as production, they not only participate in the reaction, chain extender and crosslinking effect, adjust the foam structure and opening rate, improve the resilience of the product, the rigid and mechanical properties, at the same time it also can reduce viscosity of raw material component, improve the intermiscibility raw material components.
Fatty alcohol type chain extension agent in polyurethane elastomer, coating, and other products, especially the MDI PUR products, is a widely used chain extender. In the new development of alcohol chain extender, the abbreviation for HQEE and its ehrs worth two glycol chain extender with aromatic ring.
In fatty alcohol type of chain extender, except the compounds of difunctional, also often use three faculties or four faculties base compound. Commonly used with trimethylolpropane and pentaerythritol, etc. They generate carbamate in reaction with isocyanate groups make molecular chain growth at the same time, also in the molecular chain of generating leads to a chain reaction, make polymer molecules to produce a certain degree of crosslinking, form a mesh structure. Production of them with ordinary dibasic alcohol or diamine, obtain some properties of polyurethane products improve and enhance.
Low molecular weight diamine compounds react with diisocyanate is very fierce, the rapid rate of gel, production is not easy to control, but it can react with isocyanate to generate cohesion high urea base, can give polyurethane polymer very good physical and mechanical properties; Generally used hindered amine compounds, one of the most famous is 3, 3 '- dichloro - 4-2 amino diphenyl methane.
Chinese name: Diethyl toluene diamine(DETDA)
Physical and chemical properties: light yellow transparent liquid, slightly soluble in water, soluble in alcohols, ethers, ketones and other polar organic solvents, and polyether, polyester polyol compatibility.
Density 1.022
Viscosity (20 ℃) ??mPa·ss290±10
Pour Point ℃-9
Boiling point of310°C
Flash Point°C161.1°C
In MOCA molecules, because in the presence of chlorine atom of the amine of ortho electronic effect and steric absorption function, thus reduce amino reactivity of appropriate, is able to adapt to the pu gel process. At the same time, it can give material excellent mechanical properties, so the MOCA has been extremely important in the production of polyurethane products chain extender;
MOCA as a white to light yellow needle-like crystals, moisture absorption ability, soluble in acetone, tetrahydrofuran, DMF solvents, soluble in ethanol, benzene, toluene, But the diamine extender chain agent in 1973, the American people for its suspected carcinogen, although after decades of system with a negative conclusion toxicity study, but the use of MOCA in many countries remains cautious.
Bayer company in 1969 developed type instead of MOCA non-toxic diamine chain extension agent, the scientific name for 3, 5-2-4 - ammonia chlorobenzoic acid isobutyl alcohol ester, name of commodity is Baytec - 1604. The chain extender slightly lower melting point and reactivity, easy machining operations, and can give excellent physical and mechanical properties of polyurethane rubber. But the deficiency of the chain extender is it brown after melting, applies only to the preparation of brunet high-performance PUR products.
A second aromatic liquid containing MOCA aromatic amine chain extension agent, the average relative molecular quality amine compounds 640. It is mainly used for casting type polyurea (polyurethane) ADA 890
Primary amine difunctional degrees. Mainly used for polyurethane, polyurea and epoxy resin, have good adhesion.
Double ammonia DA 145 N, N - propyl methyl amine. Low viscosity aliphatic binary primary amine, used for polyurethane and polyurea highly active, also used in epoxy resin curing agent.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
In the synthesis of polyurethane foam, the most used is 1, 4 - butanediol. Polyurethane is A basic linear structure (A - B) x type block copolymer, the soft chain segment composed, polyethylene glycol macromolecular chain of hard segment is composed, diisocyanate and low molecular diol reaction and 1, 4 - butanediol has A moderate carbon - carbon chain length, can make the soft and hard chain segment produces micro zone to separation, carbamate hard chain segment crystalline better, even if have to MDI - 1, 4 butanediol hard chain can well orientation.
Crystallization and orientation arrangement makes it easier for between polymer molecular chain to form hydrogen, means that can produce good orderly crystal, crystal resistance effect and polymer chain segment of migration, finally show the polymer has excellent toughness and hardness.
Is given priority to with fatty alcohol kind of chain extender, the bubble in the products, is mainly used in high elastic resilient soft, semi-hard foam, rigid RIM and microporous elastomer products such as production, they not only participate in the reaction, chain extender and crosslinking effect, adjust the foam structure and opening rate, improve the resilience of the product, the rigid and mechanical properties, at the same time it also can reduce viscosity of raw material component, improve the intermiscibility raw material components.
Fatty alcohol type chain extension agent in polyurethane elastomer, coating, and other products, especially the MDI PUR products, is a widely used chain extender. In the new development of alcohol chain extender, the abbreviation for HQEE and its ehrs worth two glycol chain extender with aromatic ring.
In fatty alcohol type of chain extender, except the compounds of difunctional, also often use three faculties or four faculties base compound. Commonly used with trimethylolpropane and pentaerythritol, etc. They generate carbamate in reaction with isocyanate groups make molecular chain growth at the same time, also in the molecular chain of generating leads to a chain reaction, make polymer molecules to produce a certain degree of crosslinking, form a mesh structure. Production of them with ordinary dibasic alcohol or diamine, obtain some properties of polyurethane products improve and enhance.
Low molecular weight diamine compounds react with diisocyanate is very fierce, the rapid rate of gel, production is not easy to control, but it can react with isocyanate to generate cohesion high urea base, can give polyurethane polymer very good physical and mechanical properties; Generally used hindered amine compounds, one of the most famous is 3, 3 '- dichloro - 4-2 amino diphenyl methane.
Chinese name: Diethyl toluene diamine(DETDA)
Physical and chemical properties: light yellow transparent liquid, slightly soluble in water, soluble in alcohols, ethers, ketones and other polar organic solvents, and polyether, polyester polyol compatibility.
Density 1.022
Viscosity (20 ℃) ??mPa·ss290±10
Pour Point ℃-9
Boiling point of310°C
Flash Point°C161.1°C
In MOCA molecules, because in the presence of chlorine atom of the amine of ortho electronic effect and steric absorption function, thus reduce amino reactivity of appropriate, is able to adapt to the pu gel process. At the same time, it can give material excellent mechanical properties, so the MOCA has been extremely important in the production of polyurethane products chain extender;
MOCA as a white to light yellow needle-like crystals, moisture absorption ability, soluble in acetone, tetrahydrofuran, DMF solvents, soluble in ethanol, benzene, toluene, But the diamine extender chain agent in 1973, the American people for its suspected carcinogen, although after decades of system with a negative conclusion toxicity study, but the use of MOCA in many countries remains cautious.
Bayer company in 1969 developed type instead of MOCA non-toxic diamine chain extension agent, the scientific name for 3, 5-2-4 - ammonia chlorobenzoic acid isobutyl alcohol ester, name of commodity is Baytec - 1604. The chain extender slightly lower melting point and reactivity, easy machining operations, and can give excellent physical and mechanical properties of polyurethane rubber. But the deficiency of the chain extender is it brown after melting, applies only to the preparation of brunet high-performance PUR products.
A second aromatic liquid containing MOCA aromatic amine chain extension agent, the average relative molecular quality amine compounds 640. It is mainly used for casting type polyurea (polyurethane) ADA 890
Primary amine difunctional degrees. Mainly used for polyurethane, polyurea and epoxy resin, have good adhesion.
Double ammonia DA 145 N, N - propyl methyl amine. Low viscosity aliphatic binary primary amine, used for polyurethane and polyurea highly active, also used in epoxy resin curing agent.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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