The invention relates to a preparation method of
linear low density polyethylene. The preparation method comprises the following steps: 1, taking
methyl methacrylate and
benzoyl peroxide, adding polyisobutylene, and reacting to obtain
methyl methacrylate grafting polyisobutylene at 85-105DEG C, wherein the weight of the
methyl methacrylate accounts for 5-15% of the weight of polyisobutylene, and the weight of the
benzoyl peroxide accounts for 1-5% of the weight of polyisobutylene; 2, taking methyl
methacrylate grafting polyisobutylene, an organic anti-block agent stearamide, a dispersant zincstearate and an oxidant beta-(3,5-di-t-butyl-4-hydroxyphenyl)propionic acid n-
octadecyl alcohol ester, wherein the weight of methyl
methacrylate grafting polyisobutylene accounts for 3-15% of the weight of the linear
low density polyisobutylene, the weight of the organic anti-block agent accounts for 0.1-1% of the weight of the linear
low density polyisobutylene, the weight of the dispersant accounts for 0.05-0.5% of the weight of the linear
low density polyisobutylene, and the weight of the
antioxidant accounts for 0.1-0.5% of the weight of the linear low density polyisobutylene; and 3, mixing above materials in a high speed mixer, and extruding by a double screw extruder to prepare a
low density polyethylene film. The method has the advantages of low cost, high softness, good stability and high speed printing performance.