Portal de Periódicos da CAPES

Water‐dispersible graft copolymer mixtures prepared by electron irradiation. I. Polymerization behavior

1987; Wiley; Volume: 34; Issue: 6 Linguagem: Inglês

10.1002/app.1987.070340609

1097-4628

Shigenori Egusa, Takashi Sasaki, Miyuki Hagiwara,

Fuel Cells and Related Materials

Abstract Highly viscous systems made up of 70 wt% epoxy resin dissolved in 30 wt% monomer mixtures of acrylic acid and styrene were irradiated with 1.5 MeV electrons to initiate graft copolymerization. The temperature measurement of the systems reveals that the polymerization reaction takes place both during and after the electron‐beam exposure of about 5‐sec duration. The reaction lasts about 50 sec for a low beam current of 0.6 mA, while for a high beam current of 6.0 mA it lasts merely about 20 sec. The gel permeation chromatography (GPC) measurement of obtained products demonstrates that the molecular weight distribution of ungrafted copolymer of acrylic acid and styrene becomes strikingly broader as the beam current is lowered. The GPC data suggest that the fraction of epoxy resin having a grafted branch increases with an increase in the beam current. All of these results are interpreted in terms of the mobility and the concentration of reactive species such as polymer radicals and low molecular weight free radicals.