Carboxylic acid rare earth cross-linked PLA biodegradable plastic and preparation thereof

The invention relates to a carboxylic acid rare earth cross-linked PLA biodegradable plastic and a preparation method thereof. According to the carboxylic acid rare earth cross-linked PLA biodegradable plastic, a PLA polymer is used and is added with carboxylic acid rare earth, benzoyl peroxide (BPO), organosilane, dioctyl phthalate (DOP), talcum powder and nano-silica which respectively serve as a cross-linking agent, an initiator, a dispersing agent, a plasticizer, a filling agent and a reinforcing agent. The carboxylic acid rare earth cross-linked PLA biodegradable plastic comprises the following basic components in parts by weight: 100 parts of PLA, 2-8 parts of carboxylic acid rare earth, 0.1-0.6 part of BPO, 0.5-1 part of organosilane, 5-15 parts of talcum powder, 2-6 parts of nano-silica and 5-10 parts of DOP. The vicat softening point of the cross-linked PLA material reaches 128DEG C, the cross-linked PLA material can be used at 100DEG C, the material still has biodegradability, and can be used for manufacturing various plastic products; the material has complete biodegradability, the degradation can achieve more than 90% of the after 12 weeks in the composting test and can achieve the requirement of the biodegradable plastics.