Polypropylene acid microspheres and research _1961

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Polypropylene acid microspheres and Research

Experiment, the results are listed in Table 5. The results show that the polymerization reaction is exothermic reaction of acrolein with the reaction, the reaction temperature should be controlled in the range 15 ~ 25 ℃ appropriate. Temperature is too low, acrolein polymerization rate decreases, the reaction is not complete, the product of small particle size. If the temperature is too high, had led to the rate of polymerization of acrolein Xia, increased adhesion, so the product into a massive coagulation. Bad reaction temperature on polypropylene Mu 5 emblem of the ball turned aldehyde prepared microspheres of 2.4 Polyacrolein characterization of the product in the acrolein content was 15, pH value of 9, reaction conditions, reaction temperature 15 ℃ 3.5h, microspheres synthesized Polyacrolein, its scanning electron microscope, as shown in Figure 1. Figure 1 shows that the product is uniform micron size spherical particles. Figure 2 shows the infrared spectra of the product. Observation can be seen, 2740cm for the aldehyde group in the CH asymmetric stretching peak,[link widoczny dla zalogowanych], 1720cm for the aldehyde 410 I Industry, Hefei University of Technology (Natural Science) Vol 25 carbonyl stretching absorption peak, 1419cm for the carboxylate symmetric in c-O absorption peak, 934cm -. , 1138cm the c-O bond absorption peak. Fully shows that the polymerization in the process of oxidation and aldehyde Carney Zhaluo reaction. Circuit 1 Polyacrolein SEM images of microspheres was fast / cm1.1720c Ⅲ a 2.1419cm a 3.1] 3ScJD smoke a field 2 a 4934c microspheres infrared Polyacrolein 2.5 Polyacrolein please polymer microspheres formation mechanism of polymer microspheres Polyacrolein preliminary discussions formation mechanism is as follows: in the appropriate reaction conditions, the addition of NaOH base catalyst, acrolein can be generated in aqueous solution polymerization activity of oligomers, with the reaction, acrolein in activity of oligomers around the tiny particles to continue polymerization. And further growth from latex-like particles. Carney Zhaluo the reaction of oxidation and the presence, resulting in products with a number of surface carboxyl groups with ionization and electronegativity, so Polyacrolein emulsion stability, but this effect due to changes in the amount of surface carboxyl groups is limited, Figure 1 shows that the microspheres have a certain bond. In the IR spectrum 1657cm_ 'the C = C absorption and 934cm-. , 1138cm-1 absorption peaks exist, indicating that acrolein radical addition reaction occurred fried rice cake. 3 Conclusion In this paper, prepared by emulsifier-free emulsion polymerization of polypropylene aldehyde microspheres. Acrolein concentration in the maximum size of 15 or so products, and into a ball and particle uniformity, are well dispersed in the pH value of reaction system i 9, NaOH concentration is 0.1 ~ 0.5mol / L range and feeding a continuous dropping method is better; the optimum temperature range is 15 ~ 25 ℃ [
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