Fabrication of starch-based multi-source integrated halogen-free flame retardant in improving the fire safety of polypropylene

Aimed at increasing the fire safety of polypropylene (PP), starch-based and green flame retardant (SSPM) have been prepared. Additionally, the employment of starch as bio-based char-forming materials was aimed at replacing the petroleum-based, expensive and unsustainable carbon source. Thermal degradation tests demonstrated that as-prepared SSPM possessed good thermal expansion properties with 44.7% char residue at 600 °C. When 30 phr SSPM was added to PP by melting blending process, PP composites can acquire 26.4% LOI value and UL-94 V-1 rating. Through analyzing the thermal degradation process, the promotion effect of SSPM in char-formation was obtained. Further research on char residue has initially proposed a potential flame retardant mechanism. Therefore, this paper provided a new bio-based route in replacing the petroleum-based char source for decreasing the fire risk of PP materials in actual life.