scholarly journals Effects of Tung Oil-Based Polyols on the Thermal Stability, Flame Retardancy, and Mechanical Properties of Rigid Polyurethane Foam

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 45 ◽  
Author(s):  
Wei Zhou ◽  
Caiying Bo ◽  
Puyou Jia ◽  
Yonghong Zhou ◽  
Meng Zhang
Keyword(s):  
Thermal Stability ◽  
Polyurethane Foam ◽  
Flame Retardancy ◽  
Covalent Bond ◽  
Rigid Polyurethane Foam ◽  
Limiting Oxygen Index ◽  
Sem Micrographs ◽  
Tung Oil ◽  
Char Layer ◽  
Ring Opening Reaction

A phosphorus-containing tung oil-based polyol (PTOP) and a silicon-containing tung oil-based polyol (PTOSi) were each efficiently prepared by attaching 9,10-dihydro-9-oxa-10-phosphaphenanthrene (DOPO) and dihydroxydiphenylsilane (DPSD) directly, respectively, to the epoxidized monoglyceride of tung oil (EGTO) through a ring-opening reaction. The two new polyols were used in the formation of rigid polyurethane foam (RPUF), which displayed great thermal stability and excellent flame retardancy performance. The limiting oxygen index (LOI) value of RPUF containing 80 wt % PTOP and 80 wt % PTOSi was 24.0% and 23.4%, respectively. Fourier transfer infrared (FTIR), Nuclear Magnetic Resonance (NMR) and thermogravimetric (TG) analysis revealed that DOPO and DPSD are linked to EGTO by a covalent bond. Interestingly, PTOP and PTOSi had opposite effects on Tg and the compressive strength of RPUF, where, with the appropriate loading, the compressive strengths were 0.82 MPa and 0.25 MPa, respectively. At a higher loading of PTOP and PTOSi, the thermal conductivity of RPUF increased while the RPUF density decreased. The scanning electron microscope (SEM) micrographs showed that the size and closed areas of the RPUF cells were regular. SEM micrographs of the char after combustion showed that the char layer was compact and dense. The enhanced flame retardancy of RPUF resulted from the barrier effect of the char layer, which was covered with incombustible substance.

Influence of silicon dioxide addition and processing methods on structure, thermal stability and flame retardancy of EVA/NR blend nanocomposite foams

2020 ◽  
pp. 147776062095343
Author(s):  
Alif Walong ◽  
Bencha Thongnuanchan ◽  
Tadamoto Sakai ◽  
Natinee Lopattananon
Keyword(s):  
Thermal Stability ◽  
Silicon Dioxide ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Layered Silicate ◽  
Melt Mixing ◽  
Limiting Oxygen Index ◽  
Char Layer ◽  
Nanocomposite Foams ◽  
Silicon Based

Rubber nanocomposite foams based on 60/40 ethylene vinyl acetate (EVA)/natural rubber (NR) were melt-mixed with flame retardant silicon dioxide (SiO2) (20 parts per hundred rubber, phr), and foamed by compression molding process. In this study, the effect of mixing phenomena of SiO2 through two different compounding techniques such as direct mixing (DM) and phase selective mixing (PSM) methods on structure, thermal stability, combustility and flame retardancy of EVA/NR blend nanocomposite foams were investigated. DM method is a melt mixing of EVA, NR, layered silicate and SiO2, followed by foaming. PSM is a new method based on pre-mixing EVA with SiO2, then melt mixing of EVA/SiO2 masterbatch with NR and layered silicate, and finally foaming. Based on TEM technique, it was found that the SiO2 was exclusively located in dispersed NR phase for the sample prepared by DM method, and the SiO2 was preferably dispersed in continuous EVA matrix when PSM method was employed. However, the different mixing methods did not significantly alter their cellular structures. The thermal stability and char residue content of foamed samples with SiO2 increased obviously when compared with those of corresponding foams without SiO2. The results based on limiting oxygen index (LOI) test and oxygen bomb calorimetry indicated that the foams combined with SiO2 had better combustion resistance and flame retardancy due to barrier effect of thermally stable silicon-based char layer. Further, the SiO2 filled foamed system obtained from the PSM method showed a higher degree of improvement in thermal stability, combustion resistance and flame retardancy than that of DM method because the homogeneous dispersion of SiO2 in EVA matrix rather than the selective dispersion in NR phase. This resulted in the continuity of flame retardant EVA/SiO2 phase in the 60/40 EVA/NR nanocomposite foams, which exerted more efficient fire barrier of the silicon-based char layer.

Enhanced thermal stability and flame retardancy of polyurethane foam composites with polybenzoxazine modified ammonium polyphosphates

RSC Advances ◽  
2016 ◽  
Vol 6 (16) ◽  
pp. 13418-13425 ◽  
Author(s):  
Fubin Luo ◽  
Kun Wu ◽  
Mangeng Lu
Keyword(s):  
Thermal Stability ◽  
Thermal Behavior ◽  
Polyurethane Foam ◽  
Flame Retardancy ◽  
Ammonium Polyphosphate ◽  
Rigid Polyurethane Foam

The influence of polybenzoxazine modified ammonium polyphosphate (BMAPP) on the thermal behavior and flame retardancy of a rigid polyurethane foam (PU) are investigated using various techniques.

scholarly journals Thermal Degradation and Flame Retardant Mechanism of the Rigid Polyurethane Foam Including Functionalized Graphene Oxide

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 78 ◽  
Author(s):  
Xuexi Chen ◽  
Junfei Li ◽  
Ming Gao
Keyword(s):  
Graphene Oxide ◽  
Thermal Degradation ◽  
Flame Retardant ◽  
Polyurethane Foam ◽  
Main Stage ◽  
Rigid Polyurethane Foam ◽  
Functionalized Graphene ◽  
Functionalized Graphene Oxide ◽  
Limiting Oxygen Index ◽  
Char Layer

A flame retardant rigid polyurethane foam (RPUF) system containing functionalized graphene oxide (fGO), expandable graphite (EG), and dimethyl methyl phosphonate (DMMP) was prepared and investigated. The results show that the limiting oxygen index (LOI) of the flame-retardant-polyurethane-fGO (FRPU/fGO) composites reached 28.1% and UL-94 V-0 rating by adding only 0.25 g fGO. The thermal degradation of FRPU samples was studied using thermogravimetric analysis (TG) and the Fourier transform infrared (FT-IR) analysis. The activation energies (Ea) for the main stage of thermal degradation were obtained using the Kissinger equation. It was found that the fGO can considerably increase the thermal stability and decrease the flammability of RPUF. Additionally, the Ea of FRPU/fGO reached 191 kJ·mol−1, which was 61 kJ·mol−1 higher than that of the pure RPUF (130 kJ·mol−1). Moreover, scanning electron microscopy (SEM) results showed that fGO strengthened the compactness and the strength of the “vermicular” intumescent char layer improved the insulation capability of the char layer to gas and heat.

scholarly journals Environmentally Friendly Flame-Retardant and Its Application in Rigid Polyurethane Foam

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yongjun Chen ◽  
Zhixin Jia ◽  
Yuanfang Luo ◽  
Demin Jia ◽  
Bin Li
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Flame Retardant ◽  
Polyurethane Foam ◽  
Thermal Effects ◽  
Oxygen Index ◽  
Rigid Polyurethane Foam ◽  
Limiting Oxygen Index ◽  
Peak Heat Release Rate ◽  
The Impact

A novel Flame-Retardant N-(P,P′-diphenyl) phosphorus-based-(3-triethoxysilicon) propylamine (DPTP) was synthesized in this study. The impact of DPTP on the mechanical properties, thermal stability, and flame retardancy of rigid polyurethane foam (RPUF) was studied. The addition of DPTP to RPUF can significantly reduce the undesirable thermal effects and smoke density during combustion, as well as increasing the limiting oxygen index. Compared with pure RPUF, the peak heat release rate of RPUF containing 10 phr of DPTP decreased by 39.4%, while its peak smoke production rate decreased by 49.9%. However, it was also found that the addition of DPTP reduced the compressive strength of RPUF.

scholarly journals Properties of Rigid Polyurethane Foam Modified by Tung Oil-Based Polyol and Flame-Retardant Particles

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 119 ◽  
Author(s):  
Wei Zhou ◽  
Shu-Jie Hao ◽  
Guo-Dong Feng ◽  
Pu-You Jia ◽  
Xiao-Li Ren ◽  
...  
Keyword(s):  
Polyurethane Foam ◽  
Aluminum Phosphate ◽  
Rigid Polyurethane Foam ◽  
Limiting Oxygen Index ◽  
Tung Oil ◽  
Catalyst Free ◽  
Catalytic Function ◽  
Foaming Process ◽  
Rescue Time ◽  
Positive Effect

Although tung oil is renewable, with an abundant production and low price in China, and it is used to synthesize different polyols for rigid polyurethane foam (RPUF), it remains a challenge to improve the properties of RPUF by redesigning the formula. Therefore, we propose four novel compounds to strengthen the properties of RPUF, such as the catalyst-free synthesis of tung oil-based polyol (PTOK), aluminum phosphate micro-capsule (AM), silica micro-capsule (SiM), and grafted epoxidized monoglyceride of tung oil on the surface of SiO2 (SiE), which were designed and introduced into the RPUF. Because of the PTOK with a catalytic function, the foaming process of some RPUF samples was catalyst-free. The results show that the incorporation of AM, SiM, and SiE, respectively, endow RPUF with a better thermal stability at a high temperature, and the T5%, Tmax1, and Tmax2 of RPUF appeared to be reduced, however, the Tmax3 and residue rate at 800 °C were improved, which may have a positive effect on the extension of the rescue time in case of fire, and the limiting oxygen index (LOI) value was increased to 22.6%. The formula, containing 25% PTOK made the RPUF environment-friendly. The results were obtained by comparing the pore size and mechanical properties of the RPUF—the AM had a better dispersion in the foam, and the foam obtained a better mechanical, thermal, and flame retardancy.

INVESTIGATES THE INFLUENCE PHOSPHORUS-NITROGEN-CONTAINING ANTIPYRENES ON THERMAL STABILITY AND FLAME RETARDANCY OF POLYURETHANE FOAM

2021 ◽  
pp. 94-98
Author(s):  
A. A. Zakharchenko ◽  
M. A. Vaniev ◽  
A. B. Kochnov ◽  
S. V. Borisov ◽  
D. G. Nilidin ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Polyurethane Foam ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Polyurethane Foams ◽  
Limiting Oxygen Index ◽  
Phosphorus Containing

The paper investigates the influence of melamine and ammonium polyphosphates on thermal degradation and flame retardancy of polyurethane foams (PUFs) composites, based on phosphorus-containing polyol. The limiting oxygen index of PUF was increased from 27,5 to 31,5 vol. % as compared to PUF composites based on phosphorus-containing polyol. The TGA of polyurethane foams demonstrated an increase of the thermal stability. Synthesized polyurethane foams have the highest category of combustion resistance.

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