Surface modification of magnesium hydroxide using vinyltriethoxysilane by dry process

Magnesium hydroxide (MH) was modified with triethoxysilane and polymethyl-vinyl silicone rubber and used to prepare flame-retardant oil-extended styrene-ethylene-butadiene-styrene (O-SEBS)-polypropylene (PP) composites. The water contact angle of modified magnesium hydroxide (MMH) reached 141 ; this indicated that MMH possessed excellent hydrophobic properties. The samples (1.6 mm) passed the UL-94 V-0 rating during vertical burning tests when the loading amount of MH or MMH was 70 wt %. This indicated the modification did not decrease the flame-retardant properties of MH. The tensile strength and elongation at break values of the MMH-O-SEBS-PP composites increased by 20.4 and 88.9%, respectively, compared with those of the MH-O-SEBS-PP composites. The modification of MH enhanced the interfacial compatibility between the flame retardant and the matrix; thus, the mechanical performance was enhanced. Moreover, MMH was scarcely extracted after water treatment for 168 h at 70 C. As a result, the mechanical properties and flame retardancy of the MMH-O-SEBS-PP composites were well maintained after the water treatment. The modification of the MH endowed the O-SEBS-PP composites with an excellent compatibility and water-resistant performance.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Surface modification of magnesium hydroxide and its application in flame‐retardant oil‐extended styrene–ethylene–butadiene–styrene/polypropylene composites

Liu

et al. 2018

“…Compared with the XPS spectra of MH nanoparticles and MH‐WD70‐DOPO nanoparticles, we found that the intensity of C element on the surface of MH‐WD70‐DOPO nanoparticles was markedly higher than that of MH, which could be considered as a contamination. [ 16 ] In addition, the Si and P elements were present after being modified by DOPO‐WD70. These results all indicated that DOPO‐WD70 was successfully grafted on the surface of MH nanoparticles, which corresponded to the experimental results of FTIR.…”

Section: Resultsmentioning

confidence: 99%

Magnesium hydroxide nanoparticles grafted by DOPO and its flame retardancy in ethylene‐vinyl acetate copolymers

Liu

Wang

et al. 2020

Magnesium hydroxide (MH) nanoparticles have been considered as an excellent nonhalogen flame-retardant. However, the drawbacks of easy aggregation and relatively low flame retardancy limit their applications in polymer materials. In this research, MH nanoparticles were successfully grafted by 9,10dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) through the bridge of vinyl silane coupling agents (WD70). The grafted MH nanoparticles (MH-WD70-DOPO) were characterized by Fourier transform infrared spectra, 31 P nuclear magnetic resonance spectra, thermogravimetric analysis, transmission electron microscopy, and X-ray photoelectron spectroscopy spectra. MH-WD70-DOPO nanoparticles were incorporated into ethylene-vinyl acetate copolymer (EVA) matrix by melt blending method. The results indicated that MH-WD70-DOPO nanoparticles were much homogenously dispersed in EVA matrix than unmodified MH particles. EVA/MH-WD70-DOPO nanocomposites with 51.32 wt% loading showed higher flame retardancy, better mechanical and processing properties compared with EVA/MH-WD70 sample. These findings could provide a novel method to enhance the flameretardant efficiency of inorganic hydroxide flame retardants, while keeping good mechanical and processing properties of polymer materials.

“…Table shows the chemical structure of KH550, SP60, and OPE. In order to make BT nanoparticles react with surfactants, a dry surface modification process was used in virtue of high‐speed shear agitator. It is convenient, fast, and effective.…”

Section: Introductionmentioning

confidence: 99%

Dielectric property of modified barium titanate/polyamide 11 nanocomposites with different surfactants

Chen

Yang

et al. 2019

Barium titanate/polyamide 11 (BT/PA11) nanocomposites were prepared by modifying BT nanoparticles with dry surface modification process, which had well dispersion, high dielectric constant, and low dielectric loss. Various methods were reported to improve dispersion and compatibility with complex process and high cost. Herein, three surfactants [ γ‐aminopropyl triethoxy silane (KH550), sorbitan monostearate (SP60), and octadecyl phosphate ester (OPE)] were chosen to modify BT nanoparticles. Then modified‐BT nanoparticles were blended with PA11. The structure was characterized by Fourier transform infrared, scanning electron microscope, and wide angle X‐ray diffraction. Dielectric property was studied by broadband dielectric spectroscopy. The frequency dependence and temperature dependence of dielectric constant, dielectric loss, and dielectric modulus were analyzed. In general, dielectric property has strong frequency and temperature dependence. Furthermore, dielectric spectra shows that modified BT/PA11 nanocomposites have higher dielectric constant, lower dielectric loss, fewer interface polarization, and more dipole polarization. In contrast to three surfactants, OPE‐BT nanoparticles have better effects, whose dielectric constant increases from 19 to 28 at 1 Hz, and dielectric loss decreases from 0.36 to 0.23. Meanwhile, mechanical property was characterized by universal testing machine. In all, the work improves dispersion of BT nanoparticles and dielectric property with easy process and low cost. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47447.