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Unsaturated polyester resin paint crosslinking agent
2017-8-4 11:14:15
Unsaturated polyester resin paint crosslinking agent
Unsaturated polyester resin (UPR) crosslinking seems to study from theory and practice has been very thorough, but because of the complexity of the factors, which affect the crosslinking reaction, and in various application areas of UPR, products of quality defects in the very great degree almost all related to "cross linking".
Therefore, we have an in-depth discussion on unsaturated polyester resin crosslinking agent. To explore the crosslinking agent of unsaturated polyester resin, some concepts and definitions related to unsaturated polyester resin crosslinking agent should be understood.
The definition of cross-linking. The liquid UPR can be formed by the combination of the unsaturated double bond in the linear polyester chain and the double bond of the crosslinking monomer in the action of the light, heat or initiator, forming the insoluble body structure of the three-way crosslinking. This process is called the cross-linking of UPR.
Unsaturated polyester resin crosslinking agent. The crosslinking of unsaturated polyester resins is the co-polymerization reaction induced by free radicals, how to enable the reaction initiation is the key to the problem. Once a monomer is triggered, a free radical can be generated, and the molecular chain can rapidly grow to form a large molecule of three to crosslinked.
Saturated polyester resin crosslinking startup is first of all make the unsaturated C - C double bond rupture, due to chemical bonds break the amount of energy needed, for C - C key, the key to E = 350 kj/mol, should be 350-550 ℃ temperature can stimulate the cracking. It is obvious that the resin crosslinking is not practical at such a high temperature.
So people find things that can break down free radicals at a lower temperature, and that's organic peroxide. Some organic oxides of o-o can decompose free radicals at lower temperatures.
Some of them can decompose in 50-150 ℃ of peroxide crosslinking of resin is very useful. We can take advantage of this characteristic of organic peroxides and select some of them as initiators of resins, or crosslinking agents.
Definition of crosslinking agent: unsaturated polyester resin with crosslinking agent, is under the effect of promoter or other outside conditions caused a peroxide crosslinking resin, also known as the initiator and catalyst.
Chinese name: Diethyl toluene diamine(DETDA)
Chinese alias: aryl, aryl diethyl - aryl - methyl-p-phenylenediamine
English name: Benzenediamine, ar, ar-diethyl-ar-methyl-English aliases:Diethyltoluenediamine; ar, ar-Diethyl-ar-methylbenzenediamine;Diethylmethylbenzenediamine;
CAS No. :68479-98-1
EINECS No. :270 -877-4
Molecular formula: C11H18N2
Molecular Weight: 178.28
Boiling point: 310 ℃
Refractive index: 1.581
Flash Point: > 140 ℃
Inchi: InChI = 1/C11H18N2/c1-4-8-6-7 (3) 10 (12) 11 (13) 9 (8) 5-2/h6H ,4-5,12-13H2 ,1-3H3 density : 1.022
Risk Codes: R10; R35
RIDADR: UN 3082
Safety instructions: S2; S26; S39; S61
Packing Group: III
Unsaturated polyester resin (UPR) crosslinking seems to study from theory and practice has been very thorough, but because of the complexity of the factors, which affect the crosslinking reaction, and in various application areas of UPR, products of quality defects in the very great degree almost all related to "cross linking".
Therefore, we have an in-depth discussion on unsaturated polyester resin crosslinking agent. To explore the crosslinking agent of unsaturated polyester resin, some concepts and definitions related to unsaturated polyester resin crosslinking agent should be understood.
The definition of cross-linking. The liquid UPR can be formed by the combination of the unsaturated double bond in the linear polyester chain and the double bond of the crosslinking monomer in the action of the light, heat or initiator, forming the insoluble body structure of the three-way crosslinking. This process is called the cross-linking of UPR.
Unsaturated polyester resin crosslinking agent. The crosslinking of unsaturated polyester resins is the co-polymerization reaction induced by free radicals, how to enable the reaction initiation is the key to the problem. Once a monomer is triggered, a free radical can be generated, and the molecular chain can rapidly grow to form a large molecule of three to crosslinked.
Saturated polyester resin crosslinking startup is first of all make the unsaturated C - C double bond rupture, due to chemical bonds break the amount of energy needed, for C - C key, the key to E = 350 kj/mol, should be 350-550 ℃ temperature can stimulate the cracking. It is obvious that the resin crosslinking is not practical at such a high temperature.
So people find things that can break down free radicals at a lower temperature, and that's organic peroxide. Some organic oxides of o-o can decompose free radicals at lower temperatures.
Some of them can decompose in 50-150 ℃ of peroxide crosslinking of resin is very useful. We can take advantage of this characteristic of organic peroxides and select some of them as initiators of resins, or crosslinking agents.
Definition of crosslinking agent: unsaturated polyester resin with crosslinking agent, is under the effect of promoter or other outside conditions caused a peroxide crosslinking resin, also known as the initiator and catalyst.
Chinese name: Diethyl toluene diamine(DETDA)
Chinese alias: aryl, aryl diethyl - aryl - methyl-p-phenylenediamine
English name: Benzenediamine, ar, ar-diethyl-ar-methyl-English aliases:Diethyltoluenediamine; ar, ar-Diethyl-ar-methylbenzenediamine;Diethylmethylbenzenediamine;
CAS No. :68479-98-1
EINECS No. :270 -877-4
Molecular formula: C11H18N2
Molecular Weight: 178.28
Boiling point: 310 ℃
Refractive index: 1.581
Flash Point: > 140 ℃
Inchi: InChI = 1/C11H18N2/c1-4-8-6-7 (3) 10 (12) 11 (13) 9 (8) 5-2/h6H ,4-5,12-13H2 ,1-3H3 density : 1.022
Risk Codes: R10; R35
RIDADR: UN 3082
Safety instructions: S2; S26; S39; S61
Packing Group: III
Hazard Class: 6.1
The "catalyst" here is different from the traditional "catalyst". In the traditional sense, the term "catalyst" is used to help the reactants, which, while promoting the reaction, are not consumed by themselves. In UPR crosslinking reaction, peroxide must before it "catalytic reaction, alter the structure of itself, and therefore for UPR peroxide crosslinking, a more appropriate name should be called" start "or" initiator ".
two concepts that we need to know about peroxide are the active oxygen content and the critical temperature. Among them, "reactive oxygen" or "active oxygen content" is a concept which is closely related to crosslinking agent and is often misunderstood.
Ros content: the active oxygen content is simply the percentage of the total amount of oxygen and peroxide in peroxide.
From the concept itself, a lower molecular weight of peroxide may be relatively high in reactive oxygen content. However, this does not mean that the peroxide with high reactive oxygen content has more or faster activity than that of ros with low ros content. (because many applications manufacturer is we use active oxygen content as an index) assessment of crosslinking agent, in fact, active oxygen content is only as a constant of any particular peroxide concentration and purity of a scale.
People found that many have high active oxygen content of peroxide is not suitable for crosslinked resin, because they are in the standard of crosslinking temperature will quickly break down, or "exhausted", namely it down too fast of free radicals.
Due to free radicals always have a strong tendency of combination between each other, when the free radicals produced by speed faster than the speed of them is unsaturated double bond use, they will rearrange or terminate the polymer chains, resulting in a low molecular weight of polymer and cause the result of incomplete crosslinking. (a typical example is hydrogen peroxide.)
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
The "catalyst" here is different from the traditional "catalyst". In the traditional sense, the term "catalyst" is used to help the reactants, which, while promoting the reaction, are not consumed by themselves. In UPR crosslinking reaction, peroxide must before it "catalytic reaction, alter the structure of itself, and therefore for UPR peroxide crosslinking, a more appropriate name should be called" start "or" initiator ".
two concepts that we need to know about peroxide are the active oxygen content and the critical temperature. Among them, "reactive oxygen" or "active oxygen content" is a concept which is closely related to crosslinking agent and is often misunderstood.
Ros content: the active oxygen content is simply the percentage of the total amount of oxygen and peroxide in peroxide.
From the concept itself, a lower molecular weight of peroxide may be relatively high in reactive oxygen content. However, this does not mean that the peroxide with high reactive oxygen content has more or faster activity than that of ros with low ros content. (because many applications manufacturer is we use active oxygen content as an index) assessment of crosslinking agent, in fact, active oxygen content is only as a constant of any particular peroxide concentration and purity of a scale.
People found that many have high active oxygen content of peroxide is not suitable for crosslinked resin, because they are in the standard of crosslinking temperature will quickly break down, or "exhausted", namely it down too fast of free radicals.
Due to free radicals always have a strong tendency of combination between each other, when the free radicals produced by speed faster than the speed of them is unsaturated double bond use, they will rearrange or terminate the polymer chains, resulting in a low molecular weight of polymer and cause the result of incomplete crosslinking. (a typical example is hydrogen peroxide.)
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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