▎ 摘　　要

NOVELTY - A heat-resistant, biodegradable straw material comprises 63-125 pts. wt. modified polylactic acid, 20.7-95 pts. wt. auxiliary materials, 0.05-15 pts. wt. composite heat stabilizer, 2.2-16.5 pts. wt. natural antibacterial agent and 1-16 pts. wt. anti-aging agent. USE - Heat-resistant biodegradable straw material is used in hot beverage industry. ADVANTAGE - The heat-resistant biodegradable straw material has excellent temperature resistance, degradability, mechanical strength, toughness and processing characteristics. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of heat-resistant, biodegradable straw material which involves: (1) drying the modified polylactic acid and the auxiliary materials at 60-100℃ for 8-24 hours; (2) weighing modified polylactic acid, auxiliary materials, composite heat stabilizer, natural antibacterial agent and anti-aging agent, followed by mixing the components at normal temperature for 2-6 minutes; (3) adding the uniformly mixed raw materials into a screw extruder of length-diameter ratio 75:1, melt blending, the operation temperature of each temperature zone of the extruder, is 160-210℃, the screw rotation speed is 200-600 hertz (Hz), followed by cooling, bracing and granulating to form modified resin; (4) performing vacuum drying on modified resin at 50-80℃ for 6-10 hours; (5) compressing the dried modified resin as a master batch, in an extruder with compression ratio (20-40):1, melt processing, then extruding out straw through a die head; (6) cooling the extruded straw at 10-60℃ for 10-40 seconds, stretching, orientating and presetting so that the molecules in the straw are oriented, arranged and shaped, the drawing rate is 1-5 m/second; (7) fixing the straw on a microwave heating device for annealing recrystallization, so that the original molecular chain segments are disoriented under microwave heating at 60-110℃ for 20-60 seconds, the inhomogeneous crystals are disintegrated and rearranged to form more compact alpha crystals, the mechanical strength and the temperature resistance of the straw are improved; (8) subjecting straw to secondary setting after crystallization, by rapid cooling at 10-40℃ for 10-40 seconds, and drawing at speed 2-6 m/seconds as in step 6; (9) cutting the straw into fixed lengths and then air-drying.