OS Home Key Basic Research Development Program Item R Funding (G999064705) 2.3 Grafting Polymerization with Monomer In a four-neck flask add about 50 g of the ozonized sample, with different monomers at different ratios, under nitrogen protection and The graft copolymerization is carried out under conditions such as stirring. Samples are taken continuously during the reaction and each sample is taken. About 5g, add OmL flask, dilute to the mark with water. The water-soluble tribromo compound method was used to determine the monomer conversion at different reaction times.

3 CONCLUSIONS AND DISCUSSION 3.1 Polymer Ozone Oxidation and Formation of Peroxy Oxygen Figure I shows the relationship between the peroxide concentration of several polymer solutions and the time of ozonation. This type of polymer represents the polymer of different left and side chains, ozone The ease of formation of peroxy groups during formation and their relationship with time. It can be seen that regardless of whether the main oxime is an ether chain or a carbon chain, the peroxygen concentration and the ozonation time are basically linear. The slope of the graph shows that the reaction rate of the ether chain polymer is greater than that of the carbon chain. This may be due to the presence of oxygen atoms on the ether chain (strong electron-withdrawing ability), making hydrogen on the backbone carbon atoms more susceptible to ozone oxidation to form peroxy groups.

It is the relationship between the peroxide concentration and the ozonation time on the silicone rubber membrane surface. It can be seen that the superoxide concentration on the surface of the film increases with the increase of the ozonation time, and the superoxide concentration on the surface of the film at the first 10 minutes increases sharply. After 25 minutes, the change in the concentration of peroxy groups tends to be gradual to increase the grafting amount on the surface of the film. It is necessary to make the active points of the membrane surface as much as possible, so the ozonation time of the grafting reaction should be controlled at about 30 minutes.

Time/h ozonation time//mn polymer ozonation reaction time-peroxo concentration diagram Silicone rubber membrane surface peroxy radical concentration-odor (reaction temperature 25 Y) Oxidation time diagram is PPO ozone reaction time at different temperatures Peroxide concentration vs. It can be seen that the higher the temperature, the greater the ozonation reaction rate. Further studies have shown that the peroxy radical is essentially stable at the temperatures studied.

3.2 Oxidation Graft Copolymerization The silicone rubber is ozonized and grafted with methacrylic acid. Under the same reaction conditions, the polymerization was terminated after different reaction times, the grafting rate and the moisture absorption rate were determined, and the grafting rate-response time graph and the moisture absorption rate-response time graph (,) were obtained. It can be seen that as the reaction time increases, both the grafting rate and the moisture absorption rate of methacrylic acid on the silicon film increase. The moisture absorption rate increases rapidly at the beginning and then increases linearly with the grafting rate.

PPO reaction time at different temperatures in the ozone - peroxy radical concentration diagram Silicone rubber-methacrylic acid (20.5%) Graft-reaction time diagram (Ozonization time 30mm) Fixed reaction time, change the monomer solution concentration, available Grafting rate and monomer concentration diagram. The grafting rate increases with the increase of the methacrylic acid monomer concentration. From these experimental phenomena, it can be seen that increasing the grafting amount of methacrylic acid can be achieved by increasing the reaction time and increasing the monomer concentration.

Methacrylic acid (20.5%) Moisture Absorption Rate-Reaction of Ethanolamine-Methacrylic Acid Grafts-Percentage of Mass Percentage Relationship Diagram (Ozonization Time 30 min, Reaction Time 卟) (Ozonation Time 30 min) 4 Conclusion The ozone method has a wide applicability to the modification of polymer grafts and may become a general method for polymer grafting.