High-density polyethylene functionalized by cold plasma and silanes

High-density polyethylene (HDPE) surface was modified by radio-frequency discharge plasma and subsequently grafted by alkoxy silane to form a new surface containing polar functional groups. Reaction of the polar groups with vinyl silanes significantly improved hydrophilicity of the polymer. The decrease of surface energy of polymer modified by plasma in the course of ageing was stabilized by silane grafting. The changes in chemical structure of the polymer were analyzed by ATR-FTIR spectroscopy, surface roughness was studied using AFM. The surface energy, and its polar contribution of plasma modified HDPE increased, as well as peel strengths of adhesive joints to polyacrylate.

► HDPE modified by RF plasma and by alkoxy silane.
► Significantly improved hydrophilicity of polymer.
► DSC confirmed crystallinity decrease of HDPE modified by RF plasma.
► Ageing stabilized by silane grafting.