Enhanced flame retardancy of hydrophobic silica aerogels by using sodium silicate as precursor and phosphoric acid as catalyst

2018 ◽  
Vol 481 ◽  
pp. 267-275 ◽  
Author(s):  
Zhi Li ◽  
Xudong Cheng ◽  
Lunlun Gong ◽  
Qiong Liu ◽  
Shuai Li
Keyword(s):  
Phosphoric Acid ◽  
Sodium Silicate ◽  
Flame Retardancy ◽  
Silica Aerogels ◽  
Hydrophobic Silica

Preparation of Hydrophobic Silica Aerogels from Industrial Microsilica and its Oil Adsorption Properties

2012 ◽  
Vol 531-532 ◽  
pp. 103-107 ◽  
Author(s):  
Fei Shi ◽  
Jing Xiao Liu ◽  
Xiao Li Dong ◽  
Zhi Wei Zhang ◽  
Peng Cheng Du ◽  
...  
Keyword(s):  
Sodium Silicate ◽  
Hydrothermal Reaction ◽  
Ambient Pressure ◽  
Sodium Silicate Solution ◽  
Silicate Solution ◽  
Silica Aerogels ◽  
Ambient Pressure Drying ◽  
Mixed Solution ◽  
Hydrophobic Silica ◽  
Oil Adsorption

Hydrophobic silica aerogels were prepared from industrial microsilica via ambient pressure drying. The process consists of two stages, synthesis of sodium silicate solution from microsilica by hydrothermal reaction with sodium hydroxide, and preparation of silica aqueous gel and porous silica aerogels from the obtained sodium silicate solution. The mixed solution of hexane/ethanol/trimethylchlorosilane was used to modify the sol-gel derived silica aqueous gel so as to obtain porous structure by ambient pressure drying. The microstructure, pore properties of the silica aerogels were analyzed by FTIR and N2 adsorption-desorption methods, and the oil adsorption of the synthesized silica aerogels was investigated. The results indicate that the obtained silica aerogels are light-weight and hydrophobic porous materials, with the specific surface area of 767~828 m2•g-1, porosity of 91.5~95.1% and the average pore diameter of 5.22~8.02 nm. The synthesized silica aerogels have good oil adsorption capacity and the highest saturated oil adsorption rate can achieve 1105%.

Application of Calculus Equation in Solving Thermal Decomposition Kinetics Parameters of Flame Retardant Wood

2014 ◽  
Vol 983 ◽  
pp. 190-193
Author(s):  
Cai Yun Sun ◽  
Yong Li Yang ◽  
Ming Gao
Keyword(s):  
Activation Energy ◽  
Thermal Decomposition ◽  
Thermal Degradation ◽  
Phosphoric Acid ◽  
Flame Retardant ◽  
Kinetic Parameters ◽  
Flame Retardancy ◽  
Decomposition Kinetics ◽  
Thermal Decomposition Kinetics ◽  
Kinetics Parameters

Wood has been treated with amino resins and amino resins modified with phosphoric acid to impart flame retardancy. The thermal degradation of samples has been studied by thermogravimetry (TG) in air. From the resulting data, kinetic parameters for different stages of thermal degradation are obtained following the method of Broido. For the decomposition of wood and flame retardant wood, the activation energy is found to decrease from 122 to 72 kJmol-1.

Three-dimensional optofluidic waveguides in hydrophobic silica aerogels via supercritical fluid processing

2013 ◽  
Vol 73 ◽  
pp. 28-33 ◽  
Author(s):  
Gamze Eris ◽  
Deniz Sanli ◽  
Zeynep Ulker ◽  
Selmi Erim Bozbag ◽  
Alexandr Jonás ◽  
...  
Keyword(s):  
Supercritical Fluid ◽  
Three Dimensional ◽  
Silica Aerogels ◽  
Hydrophobic Silica ◽  
Optofluidic Waveguides ◽  
Supercritical Fluid Processing

Preparation and flame retardancy of epoxy resin phosphoric acid modified poly-acrylate resin

2019 ◽  
Vol 48 (3) ◽  
pp. 197-201
Author(s):  
Buqin Xu ◽  
Guilong Xu ◽  
Hui Qiao ◽  
Yun Liang ◽  
Jin Yang ◽  
...  
Keyword(s):  
Free Radical ◽  
Phosphoric Acid ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Radical Polymerization ◽  
Flame Retardancy ◽  
Phosphorous Acid ◽  
Free Radical Polymerization ◽  
Flame Resistance ◽  
Content Type

Purpose The flammability of poly-acrylate (PA) resin is a major disadvantage in applications that require flame resistance. It has been reported that a flame-retardant PA resin could be prepared by covalent incorporate phosphorous containing monomer with vinyl group via free radical polymerization, and the prepared modified PA resin is expected to exhibit better flame resistance than those by an additive approach. However, the phosphorus-containing monomers reported previously are made from expensive or toxic materials, and the production procedure is tedious and under harsh reaction conditions, which are not feasible for industrial application. Therefore, the purpose of this paper is the preparation of flame-retardant PA resin modified by epoxy resin phosphorous acid (EPPA) and the study of its flame retardancy. Design/methodology/approach EPPA is first prepared by epoxy resin E-51 and phosphorous acid and then used to prepare phosphorous containing PA resin by free radical polymerization. The flame retardancy of the prepared EPPA-modified PA (EPPA-PA) resin is studied. Findings The results show that EPPA can graft onto the PA polymer chain by free radical polymerization, the flame retardancy of the EPPA-PA resin increases as the EPPA content increasing. The flame retardancy of EPPA-PA resin prepared reaches 27.8% and can pass the V-0 rating in the UL-94 test when EPPA content is 30.0%. SEM and EDS results indicate that phosphorous element in the EPPA-PA resin shows a condensed-phase flame retardant effect. Research limitations/implications The grafting degree of EPPA cannot be accurately tested. Practical implications It is expected that the large-scale production of this epoxy resin phosphoric acid modified PA resin will enable practical industrial applications. Originality/value This method for synthesis of epoxy resin phosphoric acid modified PA resin is newfrangled.

Sign in / Sign up

Export Citation Format

Share Document