Study On The Preparation And Properties Of Poly(Lactic Acid)/Poly(Butyiene Succinate)/Nano-zinc Oxide Composites

In recent years，due to environmental pollution and a growing shortage of resources，development and utilization of environment-friendly and renewable and integratedperformance composite materials become a research emphasis，and broaden its field ofapplication is the current development trend. Accordingly，the polylactic acid biodegradablenon-petroleum-based materials has received extensive attention and application. However，the mechanical properties and thermal stability of polylactic acid limit the scope of itsapplication. In this paper，nano zinc oxide as a reinforcing filler，was added to improve thestrength of the matrix，at the same time also PLAy a nucleating agent to improve the thermalstability. Due to the small particle size and big surface area， zinc oxide prone toagglomeration，which seriously affected the dispersion of the base body，so using silanecoupling agent and titanate coupling agent modified nano-zinc oxide to reduceagglomeration， improve the uniformity degree of dispersion. The added of ZnONanoparticles reduced the toughness of the matrix，and therefore using a poly (butylenesuccinate) as a toughening component，but both the poor compatibility，so dicumylperoxide was used as cross-linking agent to improve compatibility of PBS and PLA.PLA/nano-ZnO and PLA/PBS/nano-ZnO composites were prepared by melt blending.Mechanical characterization，scan electron microscope and DSC were applied to research theproperties of composites.The following experiment results were received.1. The addition of nano-ZnO enhanced the strength of PLA. As the nano-ZnO massfraction increased，the tensile strength of PLA/nano-ZnO composites frist increased thendecreased，impact strength and the elongation at break decreased all the time.Futhermore，the spherocrystal size and crystalline rate of the sample can be reduced and accelerated,respectively. Consequently, the crystallization temperature and crystallinity can be enhanced.2. The concentration of the silane solution and titanate solution have effect theproperties of PLA. As the concertration of the two solution increased， the tensile strength， impact strength and elongation at break of PLA/nano-ZnO composites first increase，andthen decreases.When the concertration of solution was2wt%，the mechanical properties ofcomposites achieved optimal state and PLA/nano-ZnO composites had a good interfacialcompatibility， furthermore， the effect of titanate solution was better than silane solution.3. PBS toughened polylactic acid has a considerable effect. With the content of PBSincreasing，the impact strength and elongation at break of composite materials will increasedand then decreased，while the tensile strength reduced. In addition，PBS particlesprecipitated on the cross-sectional particle diameter increases rapidly， which is due to thefusion between the PLA and PBS reduced.From DSC results，there were two meltingendothermic due to PBS.4. From the mechanical results， DCP could improve mechanical properties ofcomposites，because DCP could allow PBS to blend well with PLA.From DSC results，WithDCP， the glass transition temperature， cold crystallization temperature and meltingtemperature increased，the crystallinity decreased.