News Details
Chain extender USES
2017-2-21 11:57:11
Chain extender USES: chain extension agent for the production of a variety of polymer. Extended straight chain, to improve the physical properties, at the same time will not produce the shortcoming of thermosetting plastics (also does not have the advantages of thermosetting plastic). Extension of crosslinked polymer linear block, to improve the physical properties. Will straight-chain bonding or hardening, to form a has both advantages and disadvantages of thermosetting plastics.
For polyurethane prepolymer, react with chain extension agent or curing agent, thus forming the final polymer. Chain extender and prepolymer molecular bonding together, increase the molecular weight.
Chain extender on the hard and soft block in polyurethane polymer directly impact on the distribution. The crystallization and the degree of crosslinking is also affected, depending on the structure of the chain extender and chain extender is with functions of amino or hydroxyl functionality.
Thermosetting plastic chain formed between bonding will limit its mobility and the relative displacement, thus forming certain advantages and disadvantages.
advantages
Infusibility: thermosetting plastic heat degradation, degradation is not through the density of its liquid.
In general, thermosetting plastic not drip drip in case of fire, the cohesion and need some residual physical blocking effect.
Due to the limited mobile chain, relative displacement is reduced, therefore, the temperature rise will cause modulus remain.
Due to the bonding between chain limit polymer relative displacement, therefore, therefore can produce better creep behavior.
disadvantages
The crosslinking process will extend the production cycle, and often require heating, thus increasing the cost.
Must implement the crosslinking reaction and forming the delicate balance between, so the processing difficulty will increase.
Because of the hardening of the irreversible reaction, cause waste recycling.
Chain extender is a low molecular weight products, linear and linear polymer chain segment bond for thermoplastic. If not using crosslinking agent, the final polymer will keep advantages (and disadvantages) of thermoplastics, i.e., the molecular weight increased, structure improvement.
In the process of polyurethane foam, the stand or fall of chain extender using direct impact on foam performance, sometimes affect the quality of products. Polyurethane (pu) is composed of rigid chain segments and flexible chain segment block copolymer; Rigid chain segments and the composition of flexible chain segment, in addition to the associated with polyethylene glycol and isocyanate, at the same time, the choice of chain extender and use also has a direct influence on the formation of them. Chain extender refers to can cause chain extension, expansion of compounds. In polymer formation, mainly for the double functional group of chemicals.
Unfortunately, using a chain extender agent and crosslinking agent, can't take advantage of all.
Chinese name: Diethyl toluene diamine(DETDA)
Diethyltoluenediamine packingļ¼ net weight 200KG/ galvanized iron drum (a small cabinet pallet loaded 16 tons), 1000KG/IB barrels (a small cabinet loaded 18 tons or 23 tons of ISOTANK).
The classification of the chain extender: polyurethane polymer with chain extender sort is more, according to the chemical structure of chain extender basic can be divided into alcohol and amine compounds, its functionality, are all 2 or less than 4.
The classification of the chain extender: with the rapid development of polyurethane industry and expansion of application fields, product forms, chain extension agent varieties are also increasing rapidly, but the actual use is still the glycol or secondary amine low molecular compounds.
Used in polyurethane chain extender classification and typical species list.
Polyols class Ethylene glycol, propylene glycol, 1, 4 - butanediol, a reduction of diethylene glycol, glycerin, trimethylolpropane, etc
Alicyclic alcohol 1, 4 - cyclohexanol diol, hydrogenated bisphenol A
Aromatic alcohols Second, hydroquinone and methyl phenyl glycol double - beta hydroxy ethyl ether, resorcinol hydroxyl ether
Alcohol amine, diethanolamine, triethanolamine, methyl diethanolamine
Secondary amine Two ethyl toluene diamine, 3, 5 - dimethyl sulfonium toluene diamine
Other alpha glycerin allyl ether, glycidyl allyl ether, dicumyl peroxide, sulphur
PTMG/MDI type casting polyurethane elastomer in the process of preparation, such as chain extender agent containing benzene ring, can obtain the high hardness polyurethane material, USES the chain extension agent, containing the ternary alcohol besides can reduce the hardness of pu, can also change the elastomer macromolecular structure on material, increase the elastomer crosslinking, improve some of the properties of polyurethane elastomer.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
For polyurethane prepolymer, react with chain extension agent or curing agent, thus forming the final polymer. Chain extender and prepolymer molecular bonding together, increase the molecular weight.
Chain extender on the hard and soft block in polyurethane polymer directly impact on the distribution. The crystallization and the degree of crosslinking is also affected, depending on the structure of the chain extender and chain extender is with functions of amino or hydroxyl functionality.
Thermosetting plastic chain formed between bonding will limit its mobility and the relative displacement, thus forming certain advantages and disadvantages.
advantages
Infusibility: thermosetting plastic heat degradation, degradation is not through the density of its liquid.
In general, thermosetting plastic not drip drip in case of fire, the cohesion and need some residual physical blocking effect.
Due to the limited mobile chain, relative displacement is reduced, therefore, the temperature rise will cause modulus remain.
Due to the bonding between chain limit polymer relative displacement, therefore, therefore can produce better creep behavior.
disadvantages
The crosslinking process will extend the production cycle, and often require heating, thus increasing the cost.
Must implement the crosslinking reaction and forming the delicate balance between, so the processing difficulty will increase.
Because of the hardening of the irreversible reaction, cause waste recycling.
Chain extender is a low molecular weight products, linear and linear polymer chain segment bond for thermoplastic. If not using crosslinking agent, the final polymer will keep advantages (and disadvantages) of thermoplastics, i.e., the molecular weight increased, structure improvement.
In the process of polyurethane foam, the stand or fall of chain extender using direct impact on foam performance, sometimes affect the quality of products. Polyurethane (pu) is composed of rigid chain segments and flexible chain segment block copolymer; Rigid chain segments and the composition of flexible chain segment, in addition to the associated with polyethylene glycol and isocyanate, at the same time, the choice of chain extender and use also has a direct influence on the formation of them. Chain extender refers to can cause chain extension, expansion of compounds. In polymer formation, mainly for the double functional group of chemicals.
Unfortunately, using a chain extender agent and crosslinking agent, can't take advantage of all.
Chinese name: Diethyl toluene diamine(DETDA)
Diethyltoluenediamine packingļ¼ net weight 200KG/ galvanized iron drum (a small cabinet pallet loaded 16 tons), 1000KG/IB barrels (a small cabinet loaded 18 tons or 23 tons of ISOTANK).
The classification of the chain extender: polyurethane polymer with chain extender sort is more, according to the chemical structure of chain extender basic can be divided into alcohol and amine compounds, its functionality, are all 2 or less than 4.
The classification of the chain extender: with the rapid development of polyurethane industry and expansion of application fields, product forms, chain extension agent varieties are also increasing rapidly, but the actual use is still the glycol or secondary amine low molecular compounds.
Used in polyurethane chain extender classification and typical species list.
Polyols class Ethylene glycol, propylene glycol, 1, 4 - butanediol, a reduction of diethylene glycol, glycerin, trimethylolpropane, etc
Alicyclic alcohol 1, 4 - cyclohexanol diol, hydrogenated bisphenol A
Aromatic alcohols Second, hydroquinone and methyl phenyl glycol double - beta hydroxy ethyl ether, resorcinol hydroxyl ether
Alcohol amine, diethanolamine, triethanolamine, methyl diethanolamine
Secondary amine Two ethyl toluene diamine, 3, 5 - dimethyl sulfonium toluene diamine
Other alpha glycerin allyl ether, glycidyl allyl ether, dicumyl peroxide, sulphur
PTMG/MDI type casting polyurethane elastomer in the process of preparation, such as chain extender agent containing benzene ring, can obtain the high hardness polyurethane material, USES the chain extension agent, containing the ternary alcohol besides can reduce the hardness of pu, can also change the elastomer macromolecular structure on material, increase the elastomer crosslinking, improve some of the properties of polyurethane elastomer.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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