Preparation process for high-strength PVC composite board

A preparation process for a high-strength PVC composite board, characterized by comprising the following steps:

• step 1:
• adding 20-40 parts by weight of sodium phytate modified wood powder and 5-15 parts by weight of cationic modified chlorinated polyethylene into a mixer for blending modification to obtain a first mixture,
• step 2:
• then adding 100 parts by weight of polyvinyl chloride, 3-5 parts by weight of stabilizer, 2-5 parts by weight of plasticizer, 0.4-0.8 part by weight of lubricant, 1.5-2.2 parts by weight of polyethylene wax, 5-20 parts by weight of filler, 0.8-1 part by weight of foaming agent and 2-2.8 parts by weight of blowing promoter to the first mixture to obtain a second mixture, and
• step 3:
• then extruding the second mixture into sheets from an extruder to obtain the high-strength PVC composite board;
• wherein the step 1 comprises the following steps:
• adding 20-45 parts by weight of tertiary amine monomer into isopropanol, dropwise adding concentrated hydrochloric acid solution, stirring and then adding 100 parts by weight of GMA-grafted chlorinated polyethylene, heating to 80-85 degrees C., and stirring to react for 6-12 hours, carrying out reflux condensation during reaction, and carrying out reduced pressure distillation after reaction, washing with ethanol, and drying to obtain the cationic modified chlorinated polyethylene;
• wherein the tertiary amine monomer is one of trimethylamine, triethylamine, N,N-dimethylethylamine, N,N-dimethylpropylamine and N,N-dimethylbutylamine.