Graft polymerization of arcylamide onto LLDPE film by electron beam pre‐irradiation in air or argon. I. Influence of dose, grafting temperature, and monomer concentration

Abstract

Linear low density polyethylene (LLDPE) film was irradiated by electron beam in air or argon prior to grafting in aqueous solutions of acrylamide containing 0.05% of Mohr's salt. The grafting kinetics was studied with pre‐irradiation doses in the range of 2.5–25 Mrad and in the temperature range of 40–70°C. Grafting rates and final degrees of grafting were higher for LLDPE pre‐irradiated in air than for LLDPE pre‐irradiated in argon. The overall activation energies for the grafting reaction were dose‐dependent. Above 5 Mrad, the overall activation energies were higher for LLDPE pre‐irradiated in argon which is interpreted as being due to crosslinking of the LLDPE. © 1995 John Wiley & Sons, Inc.

The grafting of acrylamide onto poly(?-caprolactone) and poly(1,5-dioxepan-2-one) using electron beam preirradiation. I. Influence of dose and Mohr's salt for the grafting onto poly(?-caprolactone)

“…This can be compared to the approximate value of 200%/h for the PAAm-(g)-LLDPE system when grafted under the same conditions. 1 The difference in R g may be explained by the more hydrophilic character of PCL than of LLDPE, which should give a difference in monomer solubility in the films. In this particular comparison, there is also a difference in crystallinity between PCL and LLDPE, i.e., 52 wt % for PCL 6 and 41 wt % for LLDPE.…”

“…1 These systems display an initial induction time followed by a seemingly linear increase in graft yield where d(GY)/dt or R g is constant, and they eventually reach a final graft yield, G f , where R g is equal to zero.…”

“…In this particular comparison, there is also a difference in crystallinity between PCL and LLDPE, i.e., 52 wt % for PCL 6 and 41 wt % for LLDPE. 1 Assuming that trapped radicals dominate the initiation, the different crystallinities may lead to different amounts of initiating species upon irradiation.…”

“…1 Briefly, the EB irradiation was performed with a 6.5 MeV pulsed electron accelerator (Microtrone, Acceleratorteknik, The Royal Institute of Technology, Stockholm). The PCL-samples were irradiated to a dose of 2.5 to 20 Mrad on a cooling plate kept at 2.5°C in air at an average dose rate of 0.83 Mrad per min.…”

“…In earlier investigations [1][2][3] , we have studied the kinetics and morphology when grafting a hydrophilic monomer, acrylamide (AAm), onto solid polyethylene, which had been irradiated by electron beam (EB). This technique makes it possible to achieve grafting of a polymeric substrate from surface to bulk depending on the electron energy and the grafting conditions.…”