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 ◽  
...  

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.

Polymers ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 45 ◽  
Author(s):  
Wei Zhou ◽  
Caiying Bo ◽  
Puyou Jia ◽  
Yonghong Zhou ◽  
Meng Zhang

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.


e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 235-243 ◽  
Author(s):  
Lin Liu ◽  
Rui Lv

AbstractA DOPO (9,10-dihydro-9-oxa-10-phosphaphen-anthrene-10-oxide)-based halogen-free flame retardant (ODOPM-CYC) was synthesized and incorporated in rigid polyurethane foam (RPUF). The structure of ODOPM-CYC was characterized by Fourier transform infrared spectra (FTIR), 1H NMR and 31P NMR. The effects of ODOPM-CYC on the flame resistance, mechanical performances, thermal properties and cell structure of RPUF were also investigated. The results showed that the incorporation of ODOPM-CYC strikingly enhanced flame retardant properties of RPUF. The flame retarded RPUF acquired a limiting oxygen index (LOI) value of 26% and achieved UL-94 V-0 rating with the phosphorus content of 3 wt%. The smoke production rate (SPR) also showed an obvious decrease and total smoke release (TSR) was 39.8% lower than that of neat RPUF. Besides, the results demonstrated that the incorporation of ODOPM-CYC provided RPUF better thermal stability but did not show any obvious influence on its thermal conductivity.


2018 ◽  
Vol 37 (1) ◽  
pp. 47-66 ◽  
Author(s):  
Daikun Jia ◽  
Jiyu He ◽  
Rongjie Yang

DOPO and its derivatives are excellent phosphorus-based flame retardants, which are applied to a series of polymer materials. In this article, a DOPO derivative bearing an active terminal epoxy group was synthesized using a non-solvent method. Fourier transform infrared spectroscopy, nuclear magnetic resonance, mass spectrometry, ultra-performance liquid chromatography, differential scanning calorimetry, thermogravimetric analysis, and viscosity measurements were performed to determine its molecular structure, purity, thermal performance, and fluidity. A possible fragmentation mechanism of the as-prepared DOPO derivative was analyzed using electron ionization mass spectrometer. All the results indicate that the synthesis was successful and the product had satisfactory purity and its initial decomposition temperature (T5%) under nitrogen and air atmosphere was 246°C and 240°C, respectively. Then, as a comparison with dimethyl methyl phosphonate, triethyl phosphate, and DOPO, e-DOPO was applied to a rigid polyurethane foam to investigate its effect on the flame retardancy, thermal stability, and cell morphology of polyurethane foam by limiting oxygen index, cone calorimetry, thermogravimetric analysis, and scanning electron microscopy. The results indicate that e-DOPO has a greater effect than DOPO and can effectively reduce the heat release and smoke release and improve the limiting oxygen index and thermal performance of the polyurethane foam. The cell size of the sample containing e-DOPO was more uniform.


Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 78 ◽  
Author(s):  
Xuexi Chen ◽  
Junfei Li ◽  
Ming Gao

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.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Yongjun Chen ◽  
Zhixin Jia ◽  
Yuanfang Luo ◽  
Demin Jia ◽  
Bin Li

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.


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