The invention relates to the technical field of
polymer functional material
processing, and particularly discloses a
polyethylene waterproof breathable film using PTFE micro
powder as an opening agent and a preparation method of the
polyethylene waterproof breathable film. The waterproof breathable film is prepared from the following components in parts by weight: 50-70 parts of linear low-density
polyethylene, 10-40 parts of PTFE (
Polytetrafluoroethylene) micro
powder, 3-8 parts of a modified compatilizer and an auxiliary agent. The preparation method comprises the following steps: S1, activating PTFE micro-
powder by a
silane coupling agent and
coating the PTFE micro-powder with
polyethylene wax to obtain modified micro-powder; s2, uniformly mixing all the components; s3, carrying out
melt extrusion at 180-210 DEG C through a double-screw extruder, and carrying out
tape casting to form a cast sheet; s4, the
casting piece is heated to 90-115 DEG C for two-way stretching, and micropores are formed through interface stripping between the PTFE particles and the base body; and S5, carrying out
heat setting at 120-130 DEG C, cooling, and rolling to form the film. Through the synergistic effect of the self-made compatilizer and the pretreatment process, the interface anchoring force is enhanced, the problems of powder falling and
water leakage of highly-filled PTFE are solved, and meanwhile, high
moisture permeability, high
hydrostatic pressure resistance and high
mechanical property are taken into account.