Study on blooming of tetrabromobisphenol a bis(2,3‐dibromopropyl ether) in blends with polypropylene

Abstract

Blends of polypropylene/tetrabromobisphenol A bis(2,3-dibromopropyl ether) (PP/TBAB) were prepared by twin-screw extruder, and then were molded into PP/TBAB plaques. Blooming of TBAB on the surface of PP/TBAB plaques were studied through heat aging test and theoretical calculation. The heat aging test at 70°C for 45 days was performed. Mass of the blooming TBAB on the surface of the plaque was measured every day in the period. Based on Fick's second law of diffusion, a mathematical method was developed to achieve concentration profile of TBAB dependent on time in the PP/TBAB plaques. Diffusion coefficients of TBAB were calculated by using the set concentration equation of TBAB with the experimental data. It was obtained that the diffusion coefficient of TBAB in PP/18 wt % TBAB is larger than that in PP/45 wt % TBAB. For the sample of PP/18 wt % TBAB, diffusion of TBAB reached an equilibrium after the heat aging for 40 days at 70°C.

Dynamics and Mechanism of Flame Retardants in Polymer Matrixes: Experiment and Simulation

“…We investigate the effects of bulky tertiary butyl groups on the dynamics of FRs in PC matrixes by employing DSIMS. , In Figure a are the density profiles (ϕ( x )) of P – ions as a function of distance from the interface at t = 1 min for both as-spun and annealed samples. As one can see in Figure a (measured at 160 °C) and Figure S1(b) (Supporting Information) (measured at 120 °C), asymmetric diffusions into a bulk PC layer were seen, and D was a single fitting parameter to fit three different spectra, obtained at various times (see, Figure S1(b), Supporting Information).…”

The Flame-Retardant Mechanisms and Preparation of Polymer Composites and Their Potential Application in Construction Engineering

“…The flame-retardant mechanism is as follows: (1) the flame retardant’s decomposition will absorb heat as the material is heated, thus reducing the temperature of the material; (2) a large amount of hydrogen halide gas is generated, which is denser than air and will gather on the surface of the material to isolate oxygen; (3) a large amount of active free radical HO·is generated in the gas phase combustion region of the material after combustion. Hydrogen halide will then react with it to generate stable inert free radicals, thus realizing the flame retardant effect [ 44 , 45 , 46 ].…”

Microstructure-Crystallization Correlation with Surface Migration of Additives in High-Crystallinity Polypropylene Composites

“…As previously described (Figure 8), due to the thin lamellar stacks formed by the crystallization of the remaining mobile lamellae between the primary stacks, the average size of the crystals increases with thermal aging for 0, 24, 48, and 72h. Studies on crystallinity suggest that rearrangements, such as secondary crystallization of semi-crystalline polymers, may be associated with changes in the crystalline and amorphous regions of PP with thermal aging [36,37]. Due to the entanglement of the lamellar stack in the intercrystalline region, the lamellar stack in the amorphous region exhibits a certain degree of mobility.…”