Autohesion of polyethylene plates by the photoinduced grafting of methaerylamide

In an attempt to provide the low- and high-density polyethylene (LDPE and HDPE) plates with the autohesive and adhesive properties at lower grafted amounts, methacry-lamide (MAAm) was photografted onto their surfaces. The surfaces of the LDPE and HDPE plates were made highly hydrophilic by the photografting of MAAm, and their wettabilities leveled off when the substrate surfaces were wholly covered with grafted PMAAm chains. The water-absorptivities of the grafted layers formed on the substrate surfaces increased with an increase in the grafted amount. The enhancement in the hydrophilicities of the LDPE and HDPE plates by the photografting of MAAm led to the development of autohesion strength as well as adhesion strength. The substrate breaking occurred at lower grafted amounts for the MAAm-grafted plates than for the plates photografted with methacrylic acid (MAA), acrylic acid (AA), and 2-(dimethylamino)ethyl methacrylate (DMAEMA).