Example 13
A 1-L jacketed glass reactor was loaded with t-butanol (2381.0 g). A monomer solution of N-vinyl-2-pyrrolidone (41.87 g), acrylic acid (27.19 g), diisobutyl fumarate (43.00 g), methyl methacrylate (37.74 g), isobutyl methacrylate (26.58 g) and 2,2,2-trifluoroethyl methacrylate (3.42 g) was prepared and charged into a syringe pump. Then, 5.0% of the monomer solution was charged into the reactor. The mixture in the reactor was de-aerated and heated to 70° C. under nitrogen with mechanical stirring at 200 rpm. At t=0, t-butyl peroxypivalate initiator (Trigonox® 25-C75, Akzo Nobel) (0.72 g) was charged into the reactor to initiate the polymerization. Then, the remaining monomer solution in the syringe pump was emptied into the reactor at a constant rate over the next 4 hours. Additional shots of the initiator were added at t=1, 2, 3, 4 hour (0.72 g each). The reaction temperature then was raised to 76° C. at t=5 hour and additional initiator was charged at t=6, 9 and 11 hour (0.72 g each). After the last initiator addition, stirring continued at 76° C. for 4 hours. After cooling, a viscous copolymer solution was discharged into a glass bottle.
The polymer was found to be at least 50% (w/w) soluble in ethanol and at least 50% (w/w) in t-butanol. The glass transition temperature (Tg) was measured at 10° C./min and found to be 114° C.