Preparation Of Nano-calcium Carbonate Masterbatch And Its Application In PLA

Polylactic acid?PLA?has good physical properties and biodegradability.It has great application prospects in real life,but its application is limited due to its poor toughness.This paper revolves around PLA toughness defects and uses different flow fields.The melt blending method is toughened and modified by using nano-calcium carbonate masterbatch and polybutylene adipate-butylene terephthalate?PBAT?,and is used for injection molding,blown film forming and Design and experiment of composite formulations were carried out in 3D printing.The effects of Nano-CaCO₃ masterbatch and PBAT on the mechanical properties,thermal properties,rheological properties and microstructure of PLA were studied systematically by DSC,SEM and rotational rheometer.The injection molded samples with good impact toughness were prepared.A blown film having good elongation at break and a 3D printed wire having good moldability.Firstly,a nano-calcium carbonate masterbatch was prepared by a twin-screw extruder and a continuous mixing unit of a two-sided rotor structure,and then the masterbatch was added to the PLA in different proportions for injection molding.The effect of Nano-CaCO₃ masterbatch and Nano-CaCO₃ content prepared by two different processing flow fields on PLA performance was investigated by characterization.The results show that the Nano-CaCO₃ masterbatch prepared by the continuous mixer is more conducive to the dispersion of Nano-CaCO₃ in the PLA matrix,reducing the complex viscosity of the material and increasing the crystallinity.When the amount of the masterbatch is the same,the"continuous mixing masterbatch""The loss of tensile strength of the material is lower,and the impact strength of the notched impact is higher.At the same time,the rotor structure of the continuous mixer?two-sided rotor and three-sided rotor?is studied for the Nano-CaCO₃ masterbatch and The influence of the properties of PLA/Nano-CaCO₃ material found that the two-sided rotor structure has stronger shear mixing effect on the material,and the prepared Nano-CaCO₃ masterbatch can improve the mechanical properties of PLA/Nano-CaCO₃ material.Secondly,the continuous mixer with the two-edge rotor structure of the optim al flow field is selected by the above chapter,respectively,with methyl methacryla te-silicone-styrene copolymer?S-2001?and glycidyl methacrylate.POE-G-GMA was an impact modifier,and"PGA masterbatch"and"S2001 masterbatch"were prepar ed to prepare a PLA/Nano-CaCO₃ film.The results show that the“PGA masterbat ch”in the masterbatch and the“S2001 masterbatch”have the most improved mec hanical properties of the composite and the compatibility of the system;.the elong ation at break of the film reaches about 34.3%?the elongation at break of pure PLA film is only about 11.3%?.Thirdly,PLA/PBAT and PLA/PBAT/Nano-CaCO₃ composites were prepared by using PBAT,masterbatch and PBAT as modifiers.At the same time,when the mixing ratio of PLA/PBAT=?70:30,wt%?,the mechanical properties of the material are good;PGA masterbatch and S2001 masterbatch effectively improve the compatibility and mechanical properties of PLA/PBAT/Nano-CaCO₃ composites;S2001 masterbatch is more The storage modulus and complex viscosity of the material can be reduced,and the ductility of the film can be improved.When the content of S2001 masterbatch is 11 wt%,the elongation at break of the PLA/PBAT/Nano-CaCO₃ composite film reaches a maximum of 479.4%.Finally,the PLA/PBAT/Nano-CaCO₃ 3D printed wire was prepared by the“masterbatch method”and the“special resin method”.The master batch method refers to the preparation of PLA/PBAT using the S2001 masterbatch for Printed wire,special resin method refers to the preparation of PLA/PBAT/Nano-CaCO₃ printing wire directly using Nano-CaCO₃ powder with reference to the masterbatch method.The results show that the wire prepared by the two methods has good printability and dimensional stability of the product,but when the powder content is too high?the Nano-CaCO₃ mass ratio exceeds 15wt%?,the printed product will collapse.The printed product prepared by the masterbatch method has higher tensile strength,lower impact strength,and darker product,which is more favorable for the appearance of the texture.