scholarly journals Functionalization of MXene Nanosheets for Polystyrene towards High Thermal Stability and Flame Retardant Properties

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 976 ◽  
Author(s):  
Jing-Yu Si ◽  
Benjamin Tawiah ◽  
Wei-Long Sun ◽  
Bo Lin ◽  
Cheng Wang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Flame Retardant ◽  
High Performance ◽  
Decyltrimethylammonium Bromide ◽  
Cone Calorimeter Test ◽  
Uniform Dispersion ◽  
Flame Retardant Properties ◽  
Octadecyltrimethylammonium Bromide ◽  
Surface Modified ◽  
Long Chain

Fabricating high-performance MXene-based polymer nanocomposites is a huge challenge because of the poor dispersion and interfacial interaction of MXene nanosheets in the polymer matrix. To address the issue, MXene nanosheets were successfully exfoliated and subsequently modified by long-chain cationic agents with different chain lengths, i.e., decyltrimethylammonium bromide (DTAB), octadecyltrimethylammonium bromide (OTAB), and dihexadecyldimethylammonium bromide (DDAB). With the long-chain groups on their surface, modified Ti3C2 (MXene) nanosheets were well dispersed in N,N-dimethylformamide (DMF), resulting in the formation of uniform dispersion and strong interfacial adhesion within a polystyrene (PS) matrix. The thermal stability properties of cationic modified Ti3C2/PS nanocomposites were improved considerably with the temperatures at 5% weight loss increasing by 20 °C for DTAB-Ti3C2/PS, 25 °C for OTAB-Ti3C2/PS and 23 °C for DDAB-Ti3C2/PS, respectively. The modified MXene nanosheets also enhanced the flame-retardant properties of PS. Compared to neat PS, the peak heat release rate (PHRR) was reduced by approximately 26.4%, 21.5% and 20.8% for PS/OTAB-Ti3C2, PS/DDAB-Ti3C2 and PS/DTAB-Ti3C2, respectively. Significant reductions in CO and CO2 productions were also obtained in the cone calorimeter test and generally lower pyrolysis volatile products were recorded by PS/OTAB-Ti3C2 compared to pristine PS. These property enhancements of PS nanocomposites are attributed to the superior dispersion, catalytic and barrier effects of Ti3C2 nanosheets.

scholarly journals Grafting Cellulose Nanocrystals With Phosphazene-containing Compound for Simultaneously Enhancing the Flame Retardancy and Mechanical Properties of Polylactic Acid

2021 ◽  
Author(s):  
Yajun Chen ◽  
Jingxiu He ◽  
Zhe Sun ◽  
Bo Xu ◽  
Juan Li ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Flame Retardant ◽  
Cellulose Nanocrystals ◽  
High Performance ◽  
Decomposition Temperature ◽  
Limit Oxygen Index ◽  
Initial Decomposition Temperature ◽  
Flame Retardant Properties ◽  
Index Value

Abstract Cellulose nanocrystals (CNCs) have been used as bio-based carbon source in intumescent system. However, CNCs have the disadvantages of low onset decomposition temperature and decompose and carbonize during processing. We, herein, demonstrated the design of phosphazene-containing CNCs (P/N-CNCs) with great thermal stability and outstanding charring ability. The TGA results showed that the initial decomposition temperature of P/N-CNCs was increased from 202.4 ℃ to 272.2 ℃ (increased by 34.5%), and the residual char at 700 ℃ was increased from 24.9 wt% to 55.8 wt% compared with CNCs. Then, flame retardant PLA composites were prepared by blending PLA, P/N-CNCs with ammonium polyphosphate (APP), melamine (MPP), aluminum hypophosphite (AHP) and piperazine pyrophosphate (PPAP), respectively. The thermal stability, flame retardant properties and mechanical properties of PLA composites were investigated. The results showed that the flame retardant system constructed by 7 wt% APP and 3 wt% P/N-CNCs had the best effect in PLA. PLA/7APP/3P/N-CNCs had the highest limit oxygen index value (28.1%), the lowest peak heat release rate (266 kW/m2) and reached UL 94 V-0 rating. Moreover, the tensile strength, impact strength and elongation at break of PLA/7APP/3P/N-CNCs were increased by 7.3%, 18.6% and 29.4%, respectively, compared with these properties of PLA/7APP/ 3CNCs. This work provides a new idea for the design of CNCs with great thermal stability and outstanding charring ability, and offers a new method for the preparation of high-performance flame-retardant PLA composites.

Synthesis of novel phosphorus-containing epoxy hardeners and thermal stability and flame-retardant properties of cured products

2012 ◽  
Vol 125 (2) ◽  
pp. 1219-1225 ◽  
Author(s):  
Yuan-Qin Xiong ◽  
Xu-Yong Zhang ◽  
Jia Liu ◽  
Ming-Ming Li ◽  
Fei Guo ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Flame Retardant ◽  
Phosphorus Containing ◽  
Flame Retardant Properties

scholarly journals Nanoreinforcements of Two-Dimensional Nanomaterials for Flame Retardant Polymeric Composites: An Overview

2019 ◽  
Vol 2019 ◽  
pp. 1-25 ◽  
Author(s):  
Shaolin Lu ◽  
Wei Hong ◽  
Xudong Chen
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Flame Retardants ◽  
Polymer Materials ◽  
Two Dimensional ◽  
Environmental Friendliness ◽  
Fire Hazards ◽  
Uniform Dispersion ◽  
Physical Barriers ◽  
Flame Retardant Properties

Polymer materials are ubiquitous in daily life. While polymers are often convenient and helpful, their properties often obscure the fire hazards they may pose. Therefore, it is of great significance in terms of safety to study the flame retardant properties of polymers while still maintaining their optimal performance. Current literature shows that although traditional flame retardants can satisfy the requirements of polymer flame retardancy, due to increases in product requirements in industry, including requirements for durability, mechanical properties, and environmental friendliness, it is imperative to develop a new generation of flame retardants. In recent years, the preparation of modified two-dimensional nanomaterials as flame retardants has attracted wide attention in the field. Due to their unique layered structures, two-dimensional nanomaterials can generally improve the mechanical properties of polymers via uniform dispersion, and they can form effective physical barriers in a matrix to improve the thermal stability of polymers. For polymer applications in specialized fields, different two-dimensional nanomaterials have potential conductivity, high thermal conductivity, catalytic activity, and antiultraviolet abilities, which can meet the flame retardant requirements of polymers and allow their use in specific applications. In this review, the current research status of two-dimensional nanomaterials as flame retardants is discussed, as well as a mechanism of how they can be applied for reducing the flammability of polymers.

scholarly journals Basalt Fiber Modified Ethylene Vinyl Acetate/Magnesium Hydroxide Composites with Balanced Flame Retardancy and Improved Mechanical Properties

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2107
Author(s):  
Dongwei Yao ◽  
Guangzhong Yin ◽  
Qingqing Bi ◽  
Xu Yin ◽  
Na Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Vinyl Acetate ◽  
Magnesium Hydroxide ◽  
Performance Enhancement ◽  
Basalt Fiber ◽  
Ethylene Vinyl Acetate ◽  
Limiting Oxygen Index ◽  
Cone Calorimeter Test ◽  
Flame Retardant Properties

In this study, we selected basalt fiber (BF) as a functional filler to improve the mechanical properties of ethylene vinyl acetate (EVA)-based flame retardant materials. Firstly, BF was modified by grafting γ-aminopropyl triethoxysilane (KH550). Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDS) were used to comprehensively prove the successful modification of the BF surface. Subsequently, the modified BF was introduced into the EVA/magnesium hydroxide (MH) composites by melt blending. The limiting oxygen index (LOI), UL-94, cone calorimeter test, tensile test, and non-notched impact test were utilized to characterize both the flame retardant properties and mechanical properties of the EVA/MH composites. It was found that the mechanical properties were significantly enhanced without reducing the flame retardant properties of the EVA/MH composites. Notably, the surface treatment with silane is a simple and low-cost method for BF surface modification and the pathway designed in this study can be both practical and effective for polymer performance enhancement.

Sign in / Sign up

Export Citation Format

Share Document