scholarly journals Structure and Flame-Retardant Actions of Rigid Polyurethane Foams with Expandable Graphite

Polymers ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 686 ◽  
Author(s):  
Yongjun Chen ◽  
Yuanfang Luo ◽  
Xiaohui Guo ◽  
Lijuan Chen ◽  
Tiwen Xu ◽  
...  
Keyword(s):  
Flame Retardancy ◽  
Photoelectron Spectroscopy ◽  
Oxygen Index ◽  
Optical Microscope ◽  
Carbon Layer ◽  
Polyurethane Foams ◽  
Limit Oxygen Index ◽  
Expandable Graphite ◽  
Rigid Polyurethane Foams ◽  
Blending Method

In this paper, rigid polyurethane foams that were filled with expandable graphite (RPUF/EG) composites were prepared by the liquid blending method, and then the structure and flame retardancy performance of materials were investigated through optical microscope, scanning electron microscope, limit oxygen index, cone calorimeter, thermogravimetric analysis coupled to fourier transform infrared spectrum, and X-ray photoelectron spectroscopy. The results showed that a large number of EG could be good to the exhibition of flame retardancy of RPUF, where the optimal material was found at loading 15 phr EG that showed an increased limit oxygen index value and a decreased calorific or fuming value. TGA coupled FTIR and XPS revealed that EG could disassembled before RPUF under heating treatment, and it could form a pyknotic and enahnced residual carbon layer on RPUF surface after the fire, which restricted the transfer of gas, like oxygen or heat into PU matrix, finally resulting in the promotion of flame retardancy of RPUF.

The effects of N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol on the flame retardancy and physical–mechanical properties of rigid polyurethane foams

2018 ◽  
Vol 36 (6) ◽  
pp. 535-545 ◽  
Author(s):  
Daikun Jia ◽  
Yi Tong ◽  
Jin Hu
Keyword(s):  
Flame Retardant ◽  
Polyurethane Foam ◽  
Flame Retardancy ◽  
Cone Calorimeter ◽  
Oxygen Index ◽  
Polyurethane Foams ◽  
Initial Decomposition Temperature ◽  
Limiting Oxygen Index ◽  
Rigid Polyurethane Foams ◽  
Upper Limit

Flame-retardant rigid polyurethane foams incorporating N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol have been prepared. After adding N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol, the density and compressive strength of the polyurethane foams were seen to decrease. The flame retardancy of the polyurethane foams has been characterized by limiting oxygen index, upper limit–94, and cone calorimeter tests. The polyurethane foam with 2.27 wt% N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol gave a highest limiting oxygen index of 33.4%, and the peak heat release rate of polyurethane foam reduced to 19.5 kW/m2 from 47.6 kW/m2 of PU-0 without N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol. Upper limit–94 revealed N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol did not change the burning rating, and all polyurethane foams had passed V-0 rating. The thermal stability of polyurethane foams has been investigated by thermogravimetric analyzer. N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol significantly increased the initial decomposition temperature of polyurethane foams and their residues. In addition, the morphology of residual char from the flame-retarded polyurethane foams after cone calorimeter tests has also been characterized by digital photographs. The results indicated that N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol significantly enhanced the strength and compatibility of the char layer formed by the polyurethane foams. These results indicate that N,N-(pyromellitoyl)-bis-l-phenylalanine diacid ester glycol can improve both the quality and quantity of the char, which has a significant effect on the flame-retardant properties of the foam.

scholarly journals Kalsiyum Hipofosfit ve Magnezyum Hipofosfit Emdirilmiş Jüt Elyaf Katkılı Poli (Laktik Asit) Biyokompozitlerinin Isıl Ve Güç Tutuşurluk Özelliklerinin İncelenmesi

2021 ◽  
Vol 28 (121) ◽  
pp. 16-22
Author(s):  
Lemiye Atabek Savaş ◽  
Ayşegül Erdem ◽  
Alperen Kaplan ◽  
Mehmet Dogan
Keyword(s):  
Flame Retardancy ◽  
Oxygen Index ◽  
Poly Lactic Acid ◽  
Limit Oxygen Index ◽  
Test Results ◽  
Melt Blending ◽  
Char Residue ◽  
Jute Fibers ◽  
Blending Method ◽  
Constant Rate

The aim of this study is to investigate the thermal and flammability properties of poly(lactic acid) (PLA) biocomposites reinforced with calcium hypophosphite (CHP) and magnesium hypophosphite (MHP) impregnated jute fiber (JE). For this purpose,biocomposites were produced by adding the jute fibers (JEs), which are treated separately with 5% and 10% CHP and MHP solutions and dried, to the PLA at a constant rate (20% wt) by melt blending method. Thermal properties of the PLA biocomposites produced were evaluated by thermogravimetic analysis (TGA), also their flammability properties were investigated by using limit oxygen index (LOI), vertical (UL-94V) and horizontal burning (UL-94HB) tests. As a result of the TGA tests, it was determined that the addition of JEs impregnated with CHP and MHP, the thermal stability and char residue amount of PLA biocomposites increased, and consequently the flame retardancy of the composites were also improved. From the LOI test results, it was observed that the LOI values of PLA biocomposites increased as the percentage of hypophosphites in the JE treatment solution increased. UL-94V and UL-94HB tests indicate that PLA biocomposite reinforced with JEs treated with 10% wt CHP has the highest flame retardancy performance.

Flame retardancy of different-sized expandable graphite particles for high-density rigid polyurethane foams

2006 ◽  
Vol 55 (8) ◽  
pp. 862-871 ◽  
Author(s):  
Lei Shi ◽  
Zhong-Ming Li ◽  
Bang-Hu Xie ◽  
Jian-Hua Wang ◽  
Chun-Rong Tian ◽  
...  
Keyword(s):  
Flame Retardancy ◽  
Polyurethane Foams ◽  
High Density ◽  
Expandable Graphite ◽  
Graphite Particles ◽  
Rigid Polyurethane Foams

scholarly journals Effects of Various Types of Expandable Graphite and Blackcurrant Pomace on the Properties of Viscoelastic Polyurethane Foams

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1801
Author(s):  
Rafał Oliwa ◽  
Joanna Ryszkowska ◽  
Mariusz Oleksy ◽  
Monika Auguścik-Królikowska ◽  
Małgorzata Gzik ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Structure ◽  
Oxygen Index ◽  
Polyurethane Foams ◽  
Expandable Graphite ◽  
Ftir Analysis ◽  
Limiting Oxygen Index ◽  
Peak Heat Release Rate ◽  
Physical And Chemical ◽  
Scanning Electron

We investigated the effect of the type and amount of expandable graphite (EG) and blackcurrant pomace (BCP) on the flammability, thermal stability, mechanical properties, physical, and chemical structure of viscoelastic polyurethane foams (VEF). For this purpose, the polyurethane foams containing EG, BCP, and EG with BCP were obtained. The content of EG varied in the range of 3–15 per hundred polyols (php), while the BCP content was 30 php. Based on the obtained results, it was found that the additional introduction of BCPs into EG-containing composites allows for an additive effect in improving the functional properties of viscoelastic polyurethane foams. As a result, the composite containing 30 php of BCP and 15 php of EG with the largest particle size and expanded volume shows the largest change in the studied parameters (hardness (H) = 2.65 kPa (+16.2%), limiting oxygen index (LOI) = 26% (+44.4%), and peak heat release rate (pHRR) = 15.5 kW/m2 (−87.4%)). In addition, this composite was characterized by the highest char yield (m600 = 17.9% (+44.1%)). In turn, the change in mechanical properties is related to a change in the physical and chemical structure of the foams as indicated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis.

A facile strategy to fabricate microencapsulated expandable graphite as a flame-retardant for rigid polyurethane foams

2015 ◽  
Vol 132 (31) ◽  
pp. n/a-n/a ◽  
Author(s):  
Xiao-Liang Zhang ◽  
Hong-Ji Duan ◽  
Ding-Xiang Yan ◽  
Li-Quan Kang ◽  
Wei-Qin Zhang ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Polyurethane Foams ◽  
Expandable Graphite ◽  
Rigid Polyurethane Foams

Expandable Graphite For Halogen-Free Flame-Retardant of High-Density Rigid Polyurethane Foams

2005 ◽  
Vol 44 (7) ◽  
pp. 1323-1337 ◽  
Author(s):  
Lei Shi ◽  
Zhong-Ming Li ◽  
Ming-Bo Yang ◽  
Bo Yin ◽  
Qiu-Ming Zhou ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Polyurethane Foams ◽  
High Density ◽  
Expandable Graphite ◽  
Rigid Polyurethane Foams ◽  
Halogen Free
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