The present invention discloses a kind of method to prepare regenerated cellulose water proof film by using bagasse pulp and wheat-straw pulp two kinds of raw material. The regenerated cellulose film prepared by cuprammonia method is firstly undergone plasticizing and drying then coated on two sides with the mixture of degradable low mole-cular weight polyurethane and unsaturated polyester, the water proof film is obtained after solidifying and crosslinking. The waterproof property of said film is good, after soaking in water for 1 hr, its strength still retains over 85%, the percentage of contraction after soaking in water for 24 hr and drying is within 4%, the permeability amount of vapour is lower than 0.01 (g/cm2.day). Said film can be substituted for non gradable plastic film used in the place where the requirement of bio-degradability is very high, such as ground film, planting film and bag for raising seedlings. |