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 Density Effect on Flame Retardancy, Thermal Degradation, and Combustibility of Rigid Polyurethane Foam Modified by Expandable Graphite or Ammonium Polyphosphate

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 668 ◽  
Author(s):  
Yang ◽  
Liu ◽  
Jiang ◽  
Chen ◽  
Wan
Keyword(s):  
Weight Loss ◽  
Thermal Degradation ◽  
Heat Release ◽  
Polyurethane Foam ◽  
Apparent Density ◽  
Flame Retardancy ◽  
Ammonium Polyphosphate ◽  
Expandable Graphite ◽  
Rigid Polyurethane Foam ◽  
Combustion Behaviors

The current study aims at comparatively investigating the effect of apparent density on flame retardancy, thermal degradation and combustion behaviors of rigid polyurethane foam (RPUF), RPUF/ expandable graphite (EG) and RPUF/ ammonium polyphosphate (APP). A series of RPUF, RPUF/EG and RPUF/APP samples with different apparent densities (30, 60 and 90 kg/m3) were prepared. The flame retardancy, thermal degradation, and combustion behaviors of each sample were investigated. Limiting oxygen index (LOI) results indicated that increasing apparent density was beneficial to the flame retardancy of all foam systems. The effect of apparent density on the enhancement of flame retardancy followed the sequence of RPUF < RPUF/APP < RPUF/EG. Thermogravimetric analysis (TGA) results showed that an increase in the apparent density can cause more weight loss in the first degradation stage and less weight loss in the second degradation stage for all foam systems. The combustion behaviors also showed significant differences. The samples with a higher apparent density showed a longer duration of heat release and higher total heat release (THR). The findings in this study demonstrated that apparent density played an important role in flame retardancy, thermal degradation, and combustion behaviors of RPUF, which must be paid more attention in the studies of flame-retardant RPUF.

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.

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