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Effect of Coating Crosslinker Structure on Glass Transition Temperature (Tg)
2017-7-11 19:48:58
Effect of Coating Crosslinker Structure on Glass Transition Temperature (Tg)
The influence of the structure of the coating crosslinker on the glass transition temperature (Tg) showed that the crosslinking of the resin / crosslinker system was more and the higher the crosslinking degree, the higher the Tg was, and the cross- Of the Tg, according to the change in Tg value to determine the cross-linked cross-linked complete degree.
Effect of crosslinker structure on glass transition temperature (Tg) In the experiments, the Tg values ??of the crosslinked materials obtained at different temperatures or different temperatures of the same temperature at different temperatures in the same time can be seen. The Tg value increases with the extension of the crosslinking time, and the law is consistent with the change trend of the epoxy index with the crosslinking time. With the increase of the crosslinking temperature, the Tg value of the crosslinked product increases gradually.
When the temperature is 100 ~ 110e, the Tg value of the cross-linked products reaches the maximum. When the crosslinking temperature continues to increase, the Tg value of the crosslinked product decreases with different degrees, indicating that the crosslinked crosslinking system structure But not completely, the degree of cross-linking decreased, which is consistent with the above-mentioned infrared spectroscopy analysis of crosslinking degree of cross-linking and cross-linking temperature is exactly the same.
When the temperature is 100 ~ 110e, the Tg value of the cross-linked products reaches the maximum. When the crosslinking temperature continues to increase, the Tg value of the crosslinked product decreases with different degrees, indicating that the crosslinked crosslinking system structure But not completely, the degree of cross-linking decreased, which is consistent with the above-mentioned infrared spectroscopy analysis of crosslinking degree of cross-linking and cross-linking temperature is exactly the same.
Cross - linked material mechanical properties. The tensile strength and elongation at break of the cross-linked products obtained by cross-linking of the three systems at different temperatures for 6 hours are related to the cross-linking reaction temperature. The tensile strength of the three systems is: A / A / DMDC and A / DMDC system, the tensile strength of A / DMDA and A / DMDC system can reach more than 70MPa.
With the increase of crosslinking temperature, the tensile strength of A / D230 cross-linked material remained basically unchanged. The tensile strength of crosslinked A / IPDA and A / DMDC system was different with the increase of crosslinking temperature This is due to the local stress generated by the local cross-linking of the crosslinking system at high temperatures, consistent with the results of the infrared tracking and Tg analysis discussed above.
The elongation at break of the cross-linked products of the A / IPDA and A / DMDC systems was as follows: A / DMDC> A / IPDA> A / D230; The A / D230 cross-linked product has an increasing tendency of the elongation at break in the high temperature stage, which is related to the high activation energy of the system and the more suitable reactivity at high temperature.
Chinese name: Diethyl toluene diamine(DETDA)Diethyltoluenediamine packing： 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 use of alicyclic crosslinking agent IPDA and DMDC cross-linked epoxy resin also has high strength and good elongation at break.
The activation energy of crosslinking reaction of A / D-230, A / IPDA and A / DMDC resin was 5916,5019,5419kJ # mol-1, the viscosity, infrared tracking analysis, the degree of reaction and the degree of reaction were obtained by DSC test. Tg, the activity sequence of the three crosslinking agents can be IPDA> DMDC> D-230.
Compared with the aliphatic cross-linking agent D-230, the use of alicyclic crosslinking agent IPDA, DMDC cross-linked epoxy resin cross-linking at the same time with high strength and high toughness, double-ring structure of the cross-linking agent DMDC can provide higher Toughness.
The crosslinking temperature of the 3221 epoxy crosslinking system using crosslinking accelerator was predicted by thermal analysis method. The crosslinking temperature was 128 ℃ ~ 130 ℃. The experimental results show that the cross-linking parameters are practical and the system can be completely cross-linked at 130 ℃ for 4h.
Accelerator 1,8-diazepine-bicyclo (5,4,0) -7-undecene (DBU): molecular formula C9H16N2, relative molecular mass 152, showing the strongest basicity in existing organic compounds , Is a super-alkaline, with strong catalytic capacity. DBU is mainly used as integrated circuit and electronic components packaging epoxy resin crosslinking accelerator. When used in the form of DBU salt, the package heat, DBU dissociation from the cross-linking to promote the role.
2-thiol-based benzothiazole (accelerator M): structural formula, light yellow monoclinic or flaky powder, slightly smelly and slightly bitter, melting point 164 ~ 175 ℃, the relative density of 1.52, soluble in ethanol, Acetone, carbon disulfide and chloroform and other organic solvents. Prepared from aniline, carbon disulfide and sulfur.
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
Copyright: Zhang Jia Gang YaRui Chemical co.,Ltd
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