▎ 摘　　要

NOVELTY - Preparing degradable polypropylene copolymer composite board comprises (i) dissolving silicon dioxide and sisal fiber in toluene solution, mixing uniformly, raising the temperature to 100degrees Celsius, introducing nitrogen, adding toluene solution of L-lactide and stannous octoate, reacting for 12-48 hours at 160degrees Celsius, filtering, washing with chloroform, drying, adding nano-cellulose ethanol solution with pH value of 4-5, mixing uniformly, continuously adding silane coupling agent, and basalt fiber, uniformly mixing, reacting for 2-3 hours, using water to wash, dissolving in the acetamide solution, uniformly mixing with polylactic acid at 60-70degrees Celsius, vacuum defoaming, drying and mixing uniformly with composite compatibilizer, extruding, cutting, hot pressing, and obtaining polylactic acid layer; (ii) mixing the carbon dioxide group, polylactic acid, polybutylene adipate terephthalate copolymer, BASF chain extender, dispersant, lubricant and filler, adding into double screw extruder. USE - The method is useful for preparing degradable polypropylene copolymer composite board. ADVANTAGE - The board has excellent mechanical strength, thermal stability and flame retardance, and strong commonality and can protect the environment, improve the global greenhouse effect, and meet the national policy. DETAILED DESCRIPTION - Preparing degradable polypropylene copolymer composite board comprises (i) dissolving silicon dioxide and sisal fiber in toluene solution, mixing uniformly, raising the temperature to 100degrees Celsius, introducing nitrogen, adding toluene solution of L-lactide and stannous octoate, reacting for 12-48 hours at 160degrees Celsius, filtering, washing with chloroform, drying, adding nano-cellulose ethanol solution with pH value of 4-5, mixing uniformly, continuously adding silane coupling agent, and basalt fiber, uniformly mixing, reacting for 2-3 hours, using water to wash, dissolving in the acetamide solution, uniformly mixing with polylactic acid at 60-70degrees Celsius, vacuum defoaming, drying and mixing uniformly with composite compatibilizer, double screw extruder, extruding, cutting, hot pressing, and obtaining polylactic acid layer; (ii) mixing the carbon dioxide group, polylactic acid, polybutylene adipate terephthalate copolymer, BASF chain extender, dispersant, lubricant, filler, uniformly mixing, double screw extruder, extruding, cutting, hot pressing, and obtaining carbon dioxide base layer; (iii) dissolving the sodium hypophosphite in aqueous solution of citric acid, adding lignin nano particles, drying, allowing to stand for 12-15 hours, drying for 45 hours at 60degrees Celsius, placing for 5 hours at 130degrees Celsius, centrifuging for 5-10 minutes, washing with water, drying and mixing the ethanol solution, adding di (2-ethyl hexyl) phosphate, reacting for 5-8 hours, de-compressing and distilling, filtering, washing with water, drying and dissolving in water, adding 4, 4'-diamino diphenylmethane, mixing uniformly, adding dry wood fiber, reacting for 5-10degrees Celsius, using double-screw extruder for extruding, cutting, hot pressing, and obtaining the lignin layer; and (iv) pre-pressing the polylactic acid layer, carbon dioxide base layer, lignin layer, hot baking, and hot rolling.