Blended composite material prepared from lactide surface grafted bamboo powder and polylactic acid, and preparation method and applications thereof

Abstract

The invention relates to a blended composite material prepared from lactide surface grafted bamboo powder and polylactic acid. According to a preparation method, bamboo powder is subjected to lactide surface grafting, wherein at a certain temperature and a certain stirring speed, a mixture of bamboo powder and lactide is reacted with the presence of stannous octoate catalyst so as to obtain lactide surface grafted bamboo powder; the lactide surface grafted bamboo powder (10 to 90 parts), polylactic acid (10 to 90 parts), and a small amount of a heat stabilizer (2 to 5 parts) are subjected to melt blending so as to obtain the blended composite material. The blended composite material can be used for thermoplastic process; is high in thermal decomposition temperature, tensile strength, elasticity modulus, and glossiness; is biodegradable; can be applied to the fields such as household plastic products, packaging, agriculture, furniture, floor, building and decorative material, and sports goods; and possesses a promising application prospect.

Description

technical field [0001] The technology relates to a composite material obtained by blending bamboo powder and polylactic acid grafted on the surface of lactide, which has the characteristics of thermoplastic processing, high thermal decomposition temperature, high tensile strength and elastic modulus, high gloss, Moreover, it is biodegradable and can be used in daily-use plastic products, packaging, agriculture, furniture, flooring, construction and decoration materials, sporting goods and other fields, and has broad application prospects. Background technique [0002] After the use of traditional plastic packaging, because it is not recycled or discarded in the natural environment because it is not easy to recycle, it pollutes the environment. Therefore, biodegradable materials and their packaging products have gradually become the current research and development hotspots. my country's national standard GB / T20197 stipulates that if a single material is tested according to G...

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Problems solved by technology

Although the patent claims to be filled with bamboo powder, there are some deficiencies: (1) since the bamboo powder itself does not have any surface treatment before blending, it is necessary to add some interfacial modifiers and plasticizers thereof in the formula, adding these additives Although the compatibility and plasticity between the biodegradable resin and the bamboo powder have been increased, these additives will affect the physical properties of the final product, and it is easy to migrate and separate out during the use process after the product is produced so that the durability of the product is not good; (2) The interfacial modifier added during the plasticizing process, due to the short residence time of the material in the extruder and other processing equipment, makes the expected reaction between the materials uncontrollable and ineffective, thus making the physical properties of the product The performance is not ideal, for example, the tensile strength of the blend of its polylactic acid and bamboo powder is below 40MPa, and the impact strength is below 10MPa, which greatly reduces its application field; (3) because the interface compatibilizer uses isocyanate chain extension (4) Auxiliary fillers such as talcum powder are required in the additives, which reduces the gloss of the product and reduces the application field of the final product.

The patent claims to fill bamboo powder, but there are some deficiencies: (1) polybutylene succinate must be added as a toughening agent, and the current price of polybutylene succinate is less than that of polylactic acid Nearly 2 times that of polylactic acid itself, the price of polylactic acid is more expensive than ordinary plastics, so that the cost of the final product after adding bamboo powder has not been reduced; The residence time is short, so that the expected reaction between the materials becomes uncontrollable and the effect is not good, and the biodegradability of the product is not complete, and it cannot contact food; (3) bamboo powder needs to use 10%wt hydrogen before processing Sodium oxide solution soaking treatment, which increases the processing links, complicates the process, and increases the cost of the final product

The above documents are mainly based on the method of banburying or laboratory solution, which is difficult to realize the continuous and efficient production requirements in the actual industry

However, the literature on the preparation of composite materials with polylactic acid after grafting bamboo powder on the surface of lactide, and the mechanical properties of the composite materials meet the application strength in many fields has not yet been reported.

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