Preparation and mechanism of polyurethane prepolymer and boric acid co‐modified phenolic foam composite: Mechanical properties, thermal stability, and flame retardant properties

2019 ◽  
Vol 30 (7) ◽  
pp. 1738-1750 ◽  
Author(s):  
Wenzong Xu ◽  
Rui Chen ◽  
Jiaying Xu ◽  
Guisong Wang ◽  
Chuanming Cheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Boric Acid ◽  
Flame Retardant ◽  
Phenolic Foam ◽  
Foam Composite ◽  
Flame Retardant Properties ◽  
Polyurethane Prepolymer

scholarly journals Lignin-Based Phenolic Foam Reinforced by Poplar Fiber and Isocyanate-Terminated Polyurethane Prepolymer

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1068
Author(s):  
Guoliang Chen ◽  
Jian Liu ◽  
Wei Zhang ◽  
Yanming Han ◽  
Derong Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Thermal Insulation ◽  
Abrasion Resistance ◽  
Chemical Structures ◽  
Phenolic Foam ◽  
Flame Retardant Properties ◽  
Novel Strategy ◽  
Hybrid Reinforcement ◽  
Polyurethane Prepolymer

Phenolic foams (PFs) are lightweight (<200 kg/m3), high-quality, and inexpensive thermal insulation materials whose heat and fire resistance are much better than those of foam plastics such as polyurethane and polystyrene. They are especially suitable for use as insulation in chemical, petroleum, construction, and other fields that are prone to fires. However, PFs have poor mechanical properties, poor abrasion resistance, and easy pulverization. In this paper, a polyurethane prepolymer was treated with an isocyanate, and then the isocyanate-terminated polyurethane prepolymer and poplar powder were used to prepare modified lignin-based phenolic foams (PUPFs), which improved the abrasion resistance and decreased the pulverization of the foam. The foam composites were comprehensively evaluated by characterizing their chemical structures, surface morphologies, mechanical properties, thermal conductivities, and flame-retardant properties. The pulverization ratio was reduced by 43.5%, and the thermal insulation performance and flame-retardancy (LOI) were improved. Compared with other methods to obtain lignin-based phenolic foam composites with anti-pulverization and flame-retardant properties, the hybrid reinforcement of foam composites with an isocyanate-terminated polyurethane prepolymer and poplar powder offers a novel strategy for an environmentally friendly alternative to the use of woody fibers.

scholarly journals Phenolic Resin Foam Composites Reinforced by Acetylated Poplar Fiber with High Mechanical Properties, Low Pulverization Ratio, and Good Thermal Insulation and Flame Retardant Performance

Materials ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 148 ◽  
Author(s):  
Jian Liu ◽  
Liuliu Wang ◽  
Wei Zhang ◽  
Yanming Han
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Thermal Insulation ◽  
Cell Structure ◽  
Value Added ◽  
Chemical Structures ◽  
Phenolic Foam ◽  
Flame Retardant Properties ◽  
Novel Strategy ◽  
Insulation Performance

Phenolic foam composites (PFs) are of substantial interest due to their uniform closed-cell structure, low thermal conductivity, and good thermal insulation performance. However, their disadvantages of a high pulverization rate and poor mechanical properties restrict their application in building exterior insulation. Therefore, the toughening of these composites is necessary. In this paper, poplar fiber was treated with an acetylation reagent, and the acetylated fiber was used to prepare modified phenolic foams (FTPFs); this successfully solved the phenomenon of the destruction of the foam structure due to the agglomeration of poplar fiber in the resin substrate. The foam composites were comprehensively evaluated via the characterization of their chemical structures, surface morphologies, mechanical properties, thermal conductivities, and flame retardant properties. It was found that the compressive strength and compressive modulus of FTPF-5% respectively increased by 28.5% and 37.9% as compared with those of PF. The pulverization ratio was reduced by 32.3%, and the thermal insulation performance and flame retardant performance (LOI) were improved. Compared with other toughening methods for phenolic foam composites, the phenolic foam composites modified with surface-compatibilized poplar fiber offer a novel strategy for the value-added utilization of woody fiber, and improve the toughness and industrial viability of phenolic foam.

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.

scholarly journals Combination of Corn Pith Fiber and Biobased Flame Retardant: A Novel Method toward Flame Retardancy, Thermal Stability, and Mechanical Properties of Polylactide

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1562
Author(s):  
Yunxian Yang ◽  
De-Yi Wang ◽  
Laia Haurie ◽  
Zhiqi Liu ◽  
Lu Zhang
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Fire Behavior ◽  
Decomposition Temperature ◽  
Industrial Applications ◽  
In Situ Modification ◽  
Novel Method ◽  
Flame Retardant Properties

Some crop by-products are considered to be promising materials for the development of novel biobased products for industrial applications. The flammability of these alternatives to conventional materials is a constraint to expanded applications. Polylactide (PLA) composites containing a combination of oxidized corn pith fiber (OCC) and a biobased flame retardant (PA-THAM) have been prepared via an in situ modification method. SEM/EDS, FTIR and TGA were performed to establish that PA-THAM was coated onto the surface of OCC. The mechanical properties, thermal stability and fire behavior of PLA-based biocomposites were investigated. The incorporation of 5 phr PA-THAM imparted biocomposite good interfacial adhesion and increased decomposition temperature at 10% mass loss by 50 °C. The flame retardant properties were also improved, as reflected by an increased LOI value, a UL-94 V-2 rating, reduction of PHRR, and increased formation of char residue. Therefore, the introduction of 5 phr PA-THAM can maintain a good balance between flame retardancy and mechanical properties of this PLA/OCC system.

The Influence of Amount of Wood Fiber on New Flame-Retardant Melamine-Urea-Formaldehyde (MUF) Composite Foam

2011 ◽  
Vol 393-395 ◽  
pp. 1012-1017 ◽  
Author(s):  
Yu Feng Ma ◽  
Wei Zhang ◽  
Ling Li ◽  
Ming Ming Zhang ◽  
Zeng Hui Cheng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Cell Shape ◽  
Urea Formaldehyde ◽  
Wood Fiber ◽  
Cell Size Distribution ◽  
Composite Foam ◽  
Composite Foams ◽  
Flame Retardant Properties ◽  
Irregular Cell

New composite foams were prepared by co-foaming of Melamine-Urea-Formaldehyde (MUF) resin and wood fiber in the closed mould at 70°C. The effects of amount of wood fiber on mechanical properties, brittleness, flame-retardant, insulation and microscopic structures of wood fiber-MUF foam were investigated. Results indicated that the flame-retardant properties increased, and the brittleness and mechanical properties decreased with the increase of the amount of wood fiber in composite foams. The addition of wood fiber resulted in more uniform cell size distribution and irregular cell shape, but had little effect on insulation properties.

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

Flammability and mechanical properties of poly(styrene–butadiene–styrene) copolymer–containing intumescent flame retardants

2015 ◽  
Vol 30 (6) ◽  
pp. 816-826 ◽  
Author(s):  
Yiren Huang ◽  
Jianwei Yang ◽  
Zhengzhou Wang
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Flame Retardants ◽  
Oxygen Index ◽  
Limiting Oxygen Index ◽  
Styrene Butadiene Styrene ◽  
Flame Retardant Properties ◽  
Intumescent Flame Retardants ◽  
Styrene Butadiene ◽  
Butadiene Styrene

Flame-retardant properties of ammonium polyphosphate (APP) and its two microcapsules, APP with a shell of melamine–formaldehyde (MF) resin (MFAPP) and APP with a shell of epoxy resin (EPAPP), were studied in styrene–butadiene–styrene (SBS). The results indicate that APP after the microencapsulation leads to an increase in limiting oxygen index in SBS compared with APP. When dipentaerythritol is incorporated into the SBS composites containing the APP microcapsules, a further improvement in flame retardancy of the composites is observed. The microencapsulation does not result in much improvement of mechanical properties. Moreover, the effect of a compatibilizer (SBS grafted with maleic anhydride) on flame-retardant and mechanical properties of SBS/APP composites was investigated.

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