Synthesis and Characterization of E-20 Epoxy Acrylate

Abstract:
E-20 epoxy acrylics are synthesized from acrylic and E-20 epoxy resins. The reaction rate model is established to predict the time required to predict the end point of the reaction. The synthesis experiment under different factors was designed with JMP software, and the influence of each factor was evaluated
the
. Factors such as catalyst, polymerizer and temperature were tested and explored under the conditions of 110 degrees C reaction temperature, 1% tribenzene catalyst (in resin quality) and 0.3% paraben ether polymerizer (in resin quality).
1 foreword
epoxy resins are widely used in coatings and various structural materials. The modified and cured epoxy resin by appropriate method can make the cured epoxy resin widely applicable to different performance requirements. Epoxy resins exhibit excellent bonding, corrosion resistance, excellent electrical insulation, high stretching, bending and compression strength and thermal stability for a variety of substrates. By acrylic to epoxy resin modified, unsaturated double bonds are introduced at both ends of the epoxy resin, enabling the resin to cure under triggers, ultraviolet light or electron radiation. And acrylic resins are more environmentally friendly and energy-efficient, with no volatile organic matter (VOC) emissions.
in this study, the esterification reaction under different catalysts, temperature, polymer inhibitors and epoxy resins and acrylic matching conditions, the JMP software was used to statistically analyze the experimental results and find suitable reaction conditions, synthesize acrylic epoxy prepolymers, and make DSC, FTIR and TGA symptom analysis.
2 Experimental part
2.1 Raw Materials
2.2 Synthesis Principles and Methods add a certain amount of E-20 and toluene to four-mouth bottles equipped with agitators, condensate tubes, drip funnels, thermometers to 80 degrees C stirring solution, to be completely dissolved after nitrogen and add a certain amount of blocker. Then heat up to 90 degrees C drop acrylic and catalyst mixture, about 1 hour after dripping, and then heat up to a certain temperature insulation. Interval sampling determines the acid value and stops the reaction when the acid value is less than 10mgK0H/g or when the interval acid value has not changed. Decompression distills the solvent toluene and obtains the product.
2.3 Analysis test
2.3.1 acid value determinationusing the national standard GB /T2895-2008 "plastic polyester resin partial acid and total acid value determination" as specified in the method to determine the acid value of the resin.
2.3.2 conversion rate
conversion rate p is defined as the proportion of acrylic-based participation in the opening ring at the t-moment. The content of acrylic carpenole can be determined by acid value.
2.3.3 epoxy value
the epoxy value of the product is determined using the method specified in the national standard GB/T1677-2008 "Measurement of epoxy value of plasticizer".
2.3.4 DSC differential scanning amount heat method
scan temperature xi-70 degrees C to 150 degrees C, heating rate of 20 degrees C/min, nitrogen protection. The glassy conversion temperature Tg took the second heating inflection point.
2.3.5 thermal heavy analysis
using Iwazu DTG-60AH type thermal heavy analyzer, heating range of 30 to 600 degrees C, heating rate of 10 degrees C/min, heating up to 200 degrees C insulation 10min after continued to heat up, nitrogen rate 50ml/min atmosphere protection.
2.3.6 Infrared Spectroscopy
using the U.S. Nicolet FTER-360 Fourier Transform Infrared Spectrometer, KBr film coating, 4000 to 400cm-1 scanning at room temperature.
3 Results and discussion of the
reaction rate model
E-20 epoxy acrylic synthesis process acid value is decreasing, the opening rate is gradually slowing down, while the inevitable polymerization reaction of ole propylene in the product causes the system viscosity to increase, and the polymerization reaction automatically accelerates. Therefore, it is necessary to determine the reaction rate to establish the reaction rate model table 2, predict the reaction endpoint to avoid the explosion of the gel.
the synthesis of E-20 cycloacrylates, the t-moment acrylic concentration c can be determined by the acid value.
assuming that the reaction is not a first-stage reaction and the upper transformation, there is a linear fit of
with lnc as the vertical axis t as the horizontal axis, with a slope of -0.1601 obtained by the least square multiplication, an intercept of 4.1890, and an R^2 of 0.9994. That is, the predicted acid value c'
: as shown in Figure 1 of the reaction model fit, the measured acid values are basically distributed on the first-level reaction prediction model. Therefore, by sampling the acid value in the previous period to establish a first-level reaction model, it can be well predicted that the end point of the reaction will take time, so as to avoid the occurrence of gel burst.
Orthographic Design
Based on the results of exploratory experiments, with reaction time and color as the target value, maintain the catalytic dosing (as opposed to E-20 mass, the same below) 1%, acrylic drop-plus process 90 degrees C constant temperature and drop in about 1 hour. The JMP software design experiment was used, in which the catalyst type, reaction temperature, esterification rate, blocker type, blocker dosage 5 factors were selected for the study object see Table 3.
results of the experiment are in Table 4. Acrylic open-loop esterification process in addition to catalyst xl, temperature x2, esterification ratio x3 blocker type x4 and blocker content x5 and other 5 factors will affect the reaction results. The catalyst and temperature also interact, taking into account the interaction between the blocker content and the type, and the prediction model is as follows:
will be 5 factors and 2 orthodectant factors, respectively, the factor variable time Yl, chroma Y2 polynoric linear fitting. The results of fitting the predicted and real interstitial values are shown in Figures 2 and 3,
the model fit and compare with the actual detection data. The verse represents the model 0 error. The P-value of the time model and the chroma model of 80% conversion rate is less than 0.0001, indicating that the hypothetical model is highly statistically significant. The time model with 80% conversion rate and RA2 of the chroma model are 0.99, 0.93, respectively, and the model has high prediction accuracy, which can be used to predict experimental results.
time forecasting model with an 80% conversion rate is as follows: 80% of the
conversion rate takes time to predict the temperature factor (x2)
correlation coefficient p less than 0.001, catalyst factor (xl) ) p is less than 0.001, the correlation coefficient of catalyst interaction with temperature (xl x2) is 0.0013, and the correlation coefficient of blocker content factor (x5) p is 0.0074. This shows that temperature, catalyst type, catalyst type and temperature interaction, the content of the blocker four factors have a significant impact on the reaction rate. The esterification ratio factor (x3), the blocker type factor (x4) blocker type and content interaction factor (x4 x5) correlation coefficient p was 0.17, 0.18, 0.41, respectively. This shows that the esterification ratio, the type of blocker and the interaction between the type of blocker and the content of the three factors have no obvious effect on the reaction rate.
reaction endpoint chromation model is predicted as follows: the relevant coefficient of the blocker type (x4) in the
reaction endpoint color prediction model is less than 0.0001, and the correlation coefficient of the blocker content (x5) is p is 0.0015, indicating that the type and content of the blocker have a significant effect on chromicity. The correlation between other factors is low, with the correlation coefficient catalyst (xl) P at 0.14, the blocker type interacting with the content (x4 x5) P at 0.31, the temperature (x2) p at 0.82, and the catalyst interacting with the temperature (x1 x2) p at 0.97.
effect of the reaction temperature The reaction temperature has an effect on both rate and color, and the temperature has a more obvious effect on the reaction rate. Figure 3, which fits the expected value, shows that when the reaction temperature is 90 degrees C, it takes 7h to achieve an 80% conversion rate. At a reaction temperature of 110 degrees C, the conversion rate of 80% can be achieved in about 1 hour. However, the temperature should not be too high, in a single experimental factor experiment in the reaction of more than 120 degrees C later prone to gel.
of the catalyst
the catalyst has a greater effect on color. Experiments using 1% catalyst, its fitting expectation Figure 3 can be seen at the same temperature of different catalysts triethylamine and triamphetamine reaction rate is similar, but triethylamine catalyst easy to make the reaction product color yellowing.
effects of the anti- Acrylic and the product's acrylic base in the reaction process will occur thermal polymerization, in order to reduce thermal polymerization needs to add polymer inhibitors. It can be seen from the fitted expected Figure 4 that the inhibitor paraphenol and paraben ether, using the glass conversion temperature of paraben products is lower, indicating that it protects the two bonds in the air thermal polymerization effect is better, and from Figure 3, it can be seen that the use of parabens as a blocker color is lower.
result, the synthetic optimization condition reaction temperature can be obtained at 110 degrees C, the catalyst is 1% tribenzene and the blocker is 0.3% paraben ether. With this condition, the synthetic product is obtained with a double-bond prepolymer acid value of 0.63mg KOH/g, an epoxy value of 0.02eq/100g, and a glass conversion temperature of 39.6 degrees C, which is analyzed by FTIR and TG.
infrared spectroscopy
acrylic and propylene in pre-polymers can be thermally polymerized at high temperatures, and this reaction is prone to occur at 110 degrees C. The ratio of carbon dual-bond feature peak 1635cm-1 to niobium-based feature peak 1730cm-1 area in infrared spectrum can be derived from the relative content of bi-bond. The relative content of the double key and the double-bond content of the prejudes can be calculated by the lower formula.
spectroscopy was performed before and after the esterification reaction of acrylic epoxy thinner. 915cm-1 is the characteristic absorption peak of epoxy base, 1635cm-1 is the characteristic absorption peak of carbon double bond, 1730cm-1 is the characteristic absorption peak of niobium base, 3435cm-1 is the absorption peak of hydroxyl hydroxyl after the epoxy group opens the ring. The final prejudes double-bond content was calculated as 99.5% by peak area integral.
thermal re-analysis
TGA thermal re-analysis of pre-accumulated matter, product solid content of 99.1%, decomposition temperature of 419 degrees C. It is shown that the toluene solvent and residual acrylic in the pre-lyse have been basically removed, and it is confirmed that the substance corresponding to the peak area of the infrared spectrum 1635cm-1 is a newly generated pre-lyse rather than acrylic residue.
4 Conclusion
acrylic resin is synthesized from epoxy resin and acrylic as raw materials, and a reaction model of the reaction rate is established to predict the time required to reach the end of the reaction. The optimization conditions for synthesis are obtained by JMP software: the reaction temperature is 110 degrees C, the catalyst is 1% tribenzene, and the blocker is 0.3% paraben ether. With this experimental condition, the complete ester epoxy resin synthesis was obtained with a two-bond prepolytic acid value of 0.63mg KOH/g, an epoxy value of 0.02eq/100g, a glassed conversion temperature of 39.6 degrees C, a double-bond content of 99.5% and a solid content of 99.1%.
/ Long Yilang
1
, Cheng Zhenshuo
1, 2
, Wang Fang
1
, Zhu Xinbao
1
1. Anhui Epoxy Resin and Additive Engineering Technology Research Center
2. Anhui Hengyuan New Materials Co., Ltd.