Polypropylene/phosphazene nanotube nanocomposites: Thermal, mechanical, and flame retardation studies

Abstract

In this study, flame retardant polypropylene (PP) nanocomposites with superior mechanical performance have been developed using amine‐functionalized phosphazene nanotubes (APZS, 1–10 wt%) through melt‐blending method. Polypropylene‐graft‐maleic anhydride was used as the compatibilizer to attain effective interaction between the nanofiller and the PP matrix. The characterization of amine‐functionalized phosphazene nanotubes (APZS) using solid‐state nuclear magnetic resonance (NMR), X‐ray photoelectron spectroscopy, X‐ray diffraction, fourier‐transform infrared (FTIR), and transmission electron microscopy indicated successful amine functionalization, though structural changes were observed as compared to the unfunctionalized nanotubes. Owing to the covalent polymer‐filler interfacial interactions and resulting in uniform filler dispersion, the nanocomposites exhibited significant enhancement in the tensile modulus up to 5 wt% APZS content (98% increment at 5 wt% content as compared to pure polymer). The addition of a small fraction of APZS (1 wt%) improved the impact strength of the nanocomposite by more than 180%. APZS acted as a weak nucleating agent for PP, thereby leading to enhanced degree of crystallinity (up to 5 wt% APZS content). The thermal stability of the nanocomposites was also enhanced with APZS content. The nanocomposites with 5 and 10 wt% APZS loading exhibited a V0 rating in UL‐94 test, indicating that APZS introduced a robust flame retardancy behavior in the PP nanocomposites. The limiting oxygen index values also confirmed the findings from the UL‐94 analysis. The developed nanocomposites exhibit high potential of use in a wide range of high temperature applications.

Effects of Different Concentrations of Arsine on the Synthesis and Final Properties of Polypropylene

“…In Figure 5 , the effect of this complex of radicals O-O-AsH-TiCl 4 -MgCl 2 is shown on the beginning of the degradation of PP, which consists of the abstraction of hydrogen in the PP-virgin, generating a stable tertiary radical, which, when reacting with a molecule O 2 , will produce a Peroxy-PP-virgin radical, which extracts hydrogen from a neighboring virgin-PP chain, thereby forming the virgin-PP-Hydroperoxide. The latter, after a homolytic rupture, will give rise to the Alkoxy-PP-Virgin radical [ 53 , 54 , 55 , 56 ]. The radical complex of O-O-ash-tiCl 4 -MgCl 2, after the abstraction of hydrogen, forms the peroxy complex H-O-O-AsH-TiCl 4 -MgCl 2 that, by hemolysis, forms the radical O-AsH-TiCl 4 -MgCl 2 .…”

Enhancing mechanical, thermal property and flame retardancy of optical polythiourethane with self‐assembly phosphazene nanoparticles

“…Meanwhile, the obtained composites exhibit better flame retardancy than other flame retardant resins according to the LOI test. [ 71,72 ] The semi‐empirical equation described by Van Krevelen [ 73 ] relates the thermogravimetric char yield to the theoretical LOI according to the following Equation (1): Where CR indicates the char yield at 850°C. The experimental and theoretical LOI values of PZS/PTU‐1 and PZS/PTU‐2 are both larger than those of pure PTU, indicating that PZS increase the fire resistance of PTU.…”

A novel lanthanum‐based phosphorus‐containing flame retardant agent and its application in polylactic acid

“…This is mainly due to the formation of crosslinks between the polymer matrix and the flame retardant particles. The interactions inhibited the rearrangement and reorientation of part of the movement units in the polymer matrix during the stretching process 55,56 . But the addition of La@DDP alone has slightly reduced Young's modulus of PLA.…”

“…The interactions inhibited the rearrangement and reorientation of part of the movement units in the polymer matrix during the stretching process. 55,56 But the addition of La@DDP alone has slightly reduced Young's modulus of PLA. The reason may be that the aggregation of La@DDP weakens the interfacial adhesion and consequently reducing the Young's modulus.…”