Effect of phosphorylated lignin on flame retardancy of polypropylene‐based composites

Abstract

Polypropylene (PP) is a synthetic polymer with excellent physical properties useful for various industries. However, its flammability in air limits its applications. In the present work, lignin filler was modified by phosphorylation, and characterized through chemical, structural, thermal, and morphological analyses. The resultant products were incorporated into PP to increase the flame retardancy of PP-based composites. Although, the mechanical properties of the PP composites containing 30 wt% filler deteriorated, the tensile strength was maintained. An addition of phosphorylated lignin (pL) into PP decreased the heat release rate from 1136.5 to 777.2 kW/m 2 and the total smoke release from 25.1 to 9.6 m 2 /m 2 . Furthermore, scanning electron microscopy images of the pL incorporated composites after the combustion test revealed that the solid char formed on the composites acted as a protective layer for PP. Thus, incorporating pL into PP is a feasible approach for improving its flame retardancy.

Bio‐Polypropylene and Polypropylene‐based Biocomposites: Solutions for a Sustainable Future

“…Similarly, Lee et al [42] noted a 17% decrease in tensile strength when 30% lignin was incorporated into PP polymer whereas inclusion dual fillers of 10 wt% and 30 wt% lignin resulted in about 4% reduction in tensile strength compared with neat PP. Recently, Lee et al [43] reported Figure 7. (a) Tensile stress-strain curves of (i) neat PP, (ii) PP/lignin composites containing 2 wt% as-received lignin, (iii) 2 wt% freeze-dried lignin from the solution with lignin concentration (conc.)…”

Effect of microstructure tuning by rapid heat cycle molding on the photodegradation behavior of isotactic polypropylene

“…17 Due to its advantages of high productivity, precision, and low cost, it is widely used in many engineering fields, such as automotive, electronics, and medical. 2,24 However, with the expansion of iPP applications and increased industrial demands for higher quality products, 25,26 conventional injection molding (CIM) often struggles to meet the growing demand. In recent years, some scholars had introduced the technique of controlling the rapid dynamic change of mold temperature, called rapid heat cycle molding (RHCM), into CIM to improve the quality of products.…”