News Details
Modified epoxy resin coating crosslinking agent
2017-7-9 15:28:56
Modified epoxy resin coating crosslinking agent
The crosslinking agent prepared by PEG800 as raw material has the longest alkali resistance after crosslinking and the amount of precipitation of compound emulsion is also less. And PEGl000 alkali resistance is weaker than the former, which is due to polyethylene glycol segment length caused by reduced cross-linking density.
Effect of modified epoxy resin on the molecular weight of polyethylene glycol in crosslinking agent. The modified epoxy resin was synthesized by the ratio of polyethylene glycol with different molecular weight and E to 51 at the mass ratio of 2.4: 1.
PEG600 alkali time is shorter, complex emulsion also has more precipitation. This is because the cross-linking performance depends not only on the cross-linking agent cross-linking the size of the size of the cross-linking agent with the size of the relationship between the ability.
The molecular structure of the crosslinked agent prepared by using the modified epoxy resin with relatively small molecular weight polyethylene glycol as the raw material has short hydrophilic group and poor emulsifying ability, so the precipitation of the compound emulsion is also more.
And because of the lack of emulsifying capacity of the cross-linking agent, will make the compound emulsion system particle size larger impact of cross-linking film when the compact, resulting in decreased alkali resistance. Therefore, E-51 and PEG800 were used as raw materials to synthesize modified epoxy resin.
The effect of raw material ratio
When the ratio of raw materials is 2.4: 1, the crosslinking agent prepared by synthesizing modified epoxy resin has the longest alkali time after crosslinking. And when the ratio of 2.8: 1 when the alkali resistance has been reduced, while the emulsion is more complex precipitation. This is due to the larger proportion of epoxy resin when the larger, the final synthesis of cross-linking agent due to lack of emulsification capacity.
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.
When the raw material ratio is 2: 1, the crosslinking agent prepared by the synthetic modified epoxy resin has good alkali resistance after crosslinking and the stability of the compound emulsion is good, The presence of side reactions will consume a portion of the epoxy groups, so that a small amount of polyethylene glycol may not react completely at a 2: 1 ratio. So the selected ratio as the synthetic modified epoxy resin the best raw material ratio.
When the raw material ratio is 2: 1, the crosslinking agent prepared by the synthetic modified epoxy resin has good alkali resistance after crosslinking and the stability of the compound emulsion is good, The presence of side reactions will consume a portion of the epoxy groups, so that a small amount of polyethylene glycol may not react completely at a 2: 1 ratio. So the selected ratio as the synthetic modified epoxy resin the best raw material ratio.
Effect of Polyamines on Crosslinking Performance. The synthesis of cross-linking agents with different polybutylene polyamines reacts with epoxy resins. When TEPA is used as raw material, the gel phenomenon occurs during the reaction, because TEPA contains more secondary amine groups, and the degree of branching is too high in the reaction to form a network crosslinked structure. The coating time of the coating film prepared with TETA as raw material is longer than that of DETA, because TETA is more than one DETA, and the crosslinking density of the crosslinking agent is higher than that of DETA. The alkali resistance of the coating after crosslinking is long.
IR. Using Vector22 type Fourier transform infrared spectroscopy.
Synthesis of Modified Epoxy Resin. Effect of Epoxy Resin on Relative Molecular Mass. The modified epoxy resin was synthesized at E-51 and E-44 with PEG800 at a mass ratio of 2.4: 1, and the alkali resistance of E-51 was better than that of E-44, because the relative molecular mass of the raw material was larger , The corresponding cross-linking agent will be the lower the density of cross-linking, film-forming density is also the corresponding lower, so its alkali resistance is also worse.
Effect of Reaction Temperature on Crosslinking Performance. The effect of different reaction temperatures on the reaction process of triethylene tetramine with modified epoxy resin or the alkali resistance of the resulting crosslinking agent.
80 ° C reaction system will produce gel, this is because the reaction temperature increases the amine on the hydrogen and epoxy reactivity increased, so that part of the middle of the segment in the middle of the secondary amine involved in the reaction, the degree of branch Increase, the formation of cross-linked network structure, resulting in gel.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Spanish
French
Italian
Portuguese
Japanese
Korean
Arabic
Russian