Polylactic acid (PLA) is often used in the preparation of environmentally friendly biodegradable polymer plastics, and how to improve the flame retardant performance of polylactic acid has been concerned by experts and scholars. Here, we provide a new idea, using bamboo activated carbon as the main material, and phytic acid, urea and Zn(NO3)2·6(H2O) as modifiers to produce a new type of carbon flame retardant. It has bamboo activated carbon as carbon source; second, it has P, N elements and metal oxides. The two synergistically play a flame retardant role on polylactic acid. The polylactic acid composite showed good thermal stability, from no grade optimization to V-0 in the UL-94 test, and the limiting oxygen index was also increased from 20.1 to 31.2%. The above tests show that bamboo activated carbon loaded with ZnO has a good flame retardant effect on polylactic acid.

Construction of polylactic acid-based flame retardant composites by zinc oxide and bamboo carbon
    Abstract
    1 Introduction
    2 Materials and methods
        2.1 Materials
        2.2 Preparation of phosphorus-containing flame retardant bamboo activated carbon
        2.3 Preparation of phosphorus-containing flame retardant bamboo activated carbonPLA composite material
        2.4 Preparation of flame-retardant composite materials
        2.5 Infrared spectral structure test
        2.6 X-ray diffraction test
        2.7 Scanning electron microscope test
        2.8 Thermal weightlessness test
        2.9 Limiting oxygen index test and (Underwriters Laboratories) UL-94 test
        2.10 CONE calorimeter test
        2.11 Nomen clature
    3 Results and discussion
        3.1 Forming and flame-retardant mechanism of PLA-based composite materials
        3.2 Morphology analysis
        3.3 Structural characterization
        3.4 Thermal stability of PLA composites
        3.5 Flame retardancy of PLA composites
        3.6 Cone calorimeter analysis
        3.7 Micro-morphology of residual carbon
    4 Conclusion
    Acknowledgements 
    References

• Mengyao Ling(College of Chemistry and Materials Engineering, Zhejiang A&F University, Hangzhou 311300, China)
• Ningning Yin(College of Chemistry and Materials Engineering, Zhejiang A&F University, Hangzhou 311300, China)
• Yifan Chen(College of Chemistry and Materials Engineering, Zhejiang A&F University, Hangzhou 311300, China)
• Zenan Zhou(College of Chemistry and Materials Engineering, Zhejiang A&F University, Hangzhou 311300, China)
• Haifeng Chen(College of Chemistry and Materials Engineering, Zhejiang A&F University, Hangzhou 311300, China)
• Chunping Dai(Faculty of Forestry, University of British Columbia, Vancouver V6T 1Z4, Canada)
• Jingda Huang(College of Chemistry and Materials Engineering, Zhejiang A&F University, Hangzhou 311300, China) Corresponding author
• Wenbiao Zhang(College of Chemistry and Materials Engineering, Zhejiang A&F University, Hangzhou 311300, China) Corresponding author