scholarly journals An Alginate Hybrid Sponge with High Thermal Stability: Its Flame Retardant Properties and Mechanism

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1973 ◽  
Author(s):  
Yuhuan Jiang ◽  
Xuening Pang ◽  
Yujia Deng ◽  
Xiaolu Sun ◽  
Xihui Zhao ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Degradation ◽  
Flame Retardant ◽  
Calcium Alginate ◽  
Degradation Mechanism ◽  
Renewable Resource ◽  
High Thermal Stability ◽  
Carbonate Content ◽  
Limiting Oxygen Index ◽  
Flame Retardant Properties

The worldwide applications of polyurethane (PU) and polystyrene (PS) sponge materials have been causing massive non-renewable resource consumption and huge loss of property and life due to its high flammability. Finding a biodegradable and regenerative sponge material with desirable thermal and flame retardant properties remains challenging to date. In this study, bio-based, renewable calcium alginate hybrid sponge materials (CAS) with high thermal stability and flame retardancy were fabricated through a simple, eco-friendly, in situ, chemical-foaming process at room temperature, followed by a facile and economical post-cross-linking method to obtain the organic-inorganic (CaCO3) hybrid materials. The microstructure of CAS showed desirable porous networks with a porosity rate of 70.3%, indicating that a great amount of raw materials can be saved to achieve remarkable cost control. The sponge materials reached a limiting oxygen index (LOI) of 39, which was greatly improved compared with common sponge. Moreover, with only 5% calcium carbonate content, the initial thermal degradation temperature of CAS was increased by 70 °C (from 150 to 220 °C), compared to that of calcium alginate, which met the requirements of high-temperature resistant and nonflammable materials. The thermal degradation mechanism of CAS was supposed based on the experimental data. The combined results suggest promising prospects for the application of CAS in a range of fields and the sponge materials provide an alternative for the commonly used PU and PS sponge materials.

Influence of Calcium Ion on Thermal Degradation and Flame Retardance Behaviour of Alginate Fiber

2013 ◽  
Vol 631-632 ◽  
pp. 447-451
Author(s):  
Guang Xiu Tian ◽  
Quan Ji ◽  
Feng Yu Quan ◽  
Yan Zhi Xia
Keyword(s):  
Thermal Degradation ◽  
Flame Retardant ◽  
Calcium Ion ◽  
Calcium Alginate ◽  
Combustion Process ◽  
Limiting Oxygen Index ◽  
Metallic Salts ◽  
Flame Retardant Properties ◽  
Alginate Fibers ◽  
Alginate Fiber

Experimental research on calcium alginate fibers thermal degradation and flame retardancy under catalysis of metallic salts was done by limiting oxygen index (LOI), scanning electron microscopy (SEM), and thermogravimetric analysis (TG) methods. LOI results show that with increasing calcium ions content, the flame retardant properties of the calcium alginate fibers improves further. The residues of calcium alginate fibers gradually retained fiber shape and on the surface of the residues the holes reduced, with the calcium ion content increasing. TG indicates temperature at maximum rate of weight loss (T-max) was clearly shifted from 246 °C for alginic acid fibers to 244°C, 236°C, 208°C, 205 °C and 203°C (SCa-1-1# calcium alginate fibers, SCa-2-2# calcium alginate fibers, SCa-3-3# calcium alginate fibers, SCa-4-4# calcium alginate fibers, SCa-5-5# calcium alginate fibers), respectively. The thermal degradation residues at 1000°C for different calcium alginate fibers are 13.7%, 16.1%, 17.2%, 18.2%, 18.4%, 19.2%, separately. Further discussion of the combustion process and flame retardant mechanism is presented.

scholarly journals Flame-Retardant and Thermal Degradation Mechanism of Caged Phosphate Charring Agent with Melamine Pyrophosphate for Polypropylene

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Xuejun Lai ◽  
Jiedong Qiu ◽  
Hongqiang Li ◽  
Xingrong Zeng ◽  
Shuang Tang ◽  
...  
Keyword(s):  
Thermal Degradation ◽  
Heat Release ◽  
Flame Retardant ◽  
Heat Release Rate ◽  
Release Rate ◽  
Degradation Mechanism ◽  
Limiting Oxygen Index ◽  
Thermal Degradation Mechanism ◽  
Charring Agent ◽  
Ul 94

An efficient caged phosphate charring agent named PEPA was synthesized and combined with melamine pyrophosphate (MPP) to flame-retard polypropylene (PP). The effects of MPP/PEPA on the flame retardancy and thermal degradation of PP were investigated by limiting oxygen index (LOI), vertical burning test (UL-94), cone calorimetric test (CCT), and thermogravimetric analysis (TGA). It was found that PEPA showed an outstanding synergistic effect with MPP in flame retardant PP. When the content of PEPA was 13.3 wt% and MPP was 6.7 wt%, the LOI value of the flame retardant PP was 33.0% and the UL-94 test was classed as a V-0 rating. Meanwhile, the peak heat release rate (PHRR), average heat release rate (AV-HRR), and average mass loss rate (AV-MLR) of the mixture were significantly reduced. The flame-retardant and thermal degradation mechanism of MPP/PEPA was investigated by TGA, Fourier transform infrared spectroscopy (FTIR), TG-FTIR, and scanning electron microscopy-energy dispersive X-ray spectrometry (SEM-EDXS). It revealed that MPP/PEPA could generate the triazine oligomer and phosphorus-containing compound radicals which changed the thermal degradation behavior of PP. Meanwhile, a compact and thermostable intumescent char was formed and covered on the matrix surface to prevent PP from degrading and burning.

scholarly journals Preparation, Characterization, Thermal, and Flame-Retardant Properties of Green Silicon-Containing Epoxy/Functionalized Graphene Nanosheets Composites

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Ming-Yuan Shen ◽  
Chen-Feng Kuan ◽  
Hsu-Chiang Kuan ◽  
Chia-Hsun Chen ◽  
Jia-Hong Wang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Flame Retardant ◽  
Graphene Nanosheets ◽  
Sol Gel ◽  
Decomposition Temperature ◽  
Gravimetric Analysis ◽  
Limiting Oxygen Index ◽  
Integral Procedure ◽  
Flame Retardant Properties ◽  
Modified Epoxy

In this investigation, silane was grafted onto the surface of graphene nanosheets (GNSs) through free radical reactions, to form Si-O-Et functional groups that can undergo the sol-gel reaction. To improve the compatibility between the polymer matrix and the fillers, epoxy monomer was modified using a silane coupling agent; then, the functionalized GNSs were added to the modified epoxy to improve the thermal stability and strengthen the flame-retardant character of the composites. High-resolution X-ray photoelectron spectrometry reveals that when the double bonds in VTES are grafted to the surfaces of GNSs. Solid-state 29Si nuclear magnetic resonance presents that the distribution of the signal associated with the T3structure is wide and significant, indicating that the functionalization reaction of the silicone in the modified epoxy and VTES-GNSs increases the network-like character of the structures. Thermal gravimetric analysis, the integral procedure decomposition temperature, and limiting oxygen index demonstrate that the GNSs composites that contained silicon had a higher thermal stability and stronger flame-retardant character than pure epoxy. The dynamic storage modulus of all of the m-GNSs containing composites was significantly higher than that of the control epoxy, and the modulus of the composites increased with the concentration of m-GNSs.

Preparation of dual-functionalized graphene oxide for the improvement of the thermal stability and flame-retardant properties of polysiloxane foam

2018 ◽  
Vol 42 (16) ◽  
pp. 13873-13883 ◽  
Author(s):  
Tianlu Xu ◽  
Chunling Zhang ◽  
Peihong Li ◽  
Xueyan Dai ◽  
Lijie Qu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Graphene Oxide ◽  
Flame Retardant ◽  
Oxygen Index ◽  
Functionalized Graphene ◽  
Foam Material ◽  
Functionalized Graphene Oxide ◽  
Limiting Oxygen Index ◽  
Flame Retardant Properties ◽  
Combustible Materials

Polysiloxane foam (PSF) is a foam material with outstanding performance. However, the limiting oxygen index (LOI) of pure PSF is only 22.0 vol%, which can be attributed to combustible materials.

scholarly journals Thermal and Flame Retardant Properties of Shaped Polypropylene Fibers Containing Modified-Thai Bentonite

2018 ◽  
Vol 18 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Chureerat Prahsarn ◽  
Nanjaporn Roungpaisan ◽  
Wattana Klinsukhon ◽  
Natthaphop Suwannamek ◽  
Sirada Padee
Keyword(s):  
Thermal Stability ◽  
Flame Retardant ◽  
High Thermal Stability ◽  
Hollow Fibers ◽  
Polypropylene Fibers ◽  
Cross Sectional ◽  
Flame Retardant Property ◽  
C Fibers ◽  
Flame Retardant Properties ◽  
Shaped Fibers

Abstract Tetraphenyl phosphonium-modified organoclay (TPP-Mt) was prepared by modifying montmorillonite-rich Thai bentonite via ion exchange. TGA results revealed that TPP-Mt possessed high thermal stability, where degradation occurred at a temperature range of 418-576°C. The obtained TPP-Mt/PP nanocomposites exhibited degradation at higher temperatures than PP (410-420°C vs. 403°C). Fibers of different cross-sectional shapes (circular, circular hollow, and cross) containing 1, 2 and 3%wt TPP-Mt were prepared and characterized. Nonwovens of 3%wt TPPMt/PP fibers were fabricated for flame retardant test. From results, nonwovens of TPP-Mt/PP fibers exhibited self-extinguishing characteristic and the areas of burning were less than that of PP nonwoven (14.5-31.6% vs. 95.6%). Nonwovens of cross-shaped fibers showed the best flame retardant property, followed by those of circular hollow and circular fibers. The flame retardant properties observed in nonwovens were explained due to the inter-fiber spaces between cross-shaped fibers and center hole in circular hollow fibers, which could trap initiating radicals inside, thus reducing flame propagation. In addition, large surface area in cross-shaped fibers could help in increasing the flame retardant effectiveness due to more exposure of TPP-Mt particles to the flame. Knowledge obtained in this study offered an approach to produce flame retardant nonwovens via a combination of modified organolcay and fiber shape.

Flame Retardancy and Pyrolysis Products of Calcium Alginate Fibers

2012 ◽  
Vol 441 ◽  
pp. 346-350 ◽  
Author(s):  
Chuan Jie Zhang ◽  
Ping Zhu ◽  
Jin Chao Zhao ◽  
Nan Nan Zhang
Keyword(s):  
Thermal Degradation ◽  
Heat Release ◽  
Flame Retardant ◽  
Sodium Alginate ◽  
Calcium Alginate ◽  
Cotton Fibers ◽  
Pyrolysis Products ◽  
Limiting Oxygen Index ◽  
Combustion Properties ◽  
Alginate Fibers

The combustion properties, flame retardant property, thermal degradation and component of pyrolysis products of calcium alginate fibers were investigated in this paper. The limiting oxygen index value of calcium alginate fibers was 34.4 showing no combustion in the air. The fiber extinguishes instantly when it is moved away from the fire. During the combustion process, the heat release rates (HRR), effective heat combustion (EHC) and total heat release (THR) of calcium alginate fibers were lower than those of cotton fibers, but higher than those of sodium alginate. The carbon dioxide yield rate of calcium alginate fibers was higher than that of cotton fibers but lower than that of sodium alginate. Calcium carbonate and calcium hydroxide, which are beneficial to hamper fibers combustion and diffusion of heat and oxygen, were formed during thermal degradation of calcium alginate fibers. There were 15 kinds of pyrolysis products in gas phase of calcium alginate fibers at 350°C and 45 kinds at 700 °C, while there were 26 kinds of pyrolysis products of sodium alginate at 350°C and 26 kinds at 700°C. Based on a series of study, the flame retardant mechanism of calcium alginate fibers was analyzed.

Thermal degradation kinetics of Opuntia Ficus Indica flour and talc-filled poly (lactic acid) hybrid biocomposites by TGA analysis

2021 ◽  
pp. 002199832110082
Author(s):  
Azzeddine Gharsallah ◽  
Abdelheq Layachi ◽  
Ali Louaer ◽  
Hamid Satha
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Thermal Degradation ◽  
Degradation Kinetics ◽  
Degradation Mechanism ◽  
Melt Processing ◽  
Thermal Degradation Kinetics ◽  
Poly Lactic Acid ◽  
Opuntia Ficus Indica ◽  
Model Free

This paper reports the effect of lignocellulosic flour and talc powder on the thermal degradation behavior of poly (lactic acid) (PLA) by thermogravimetric analysis (TGA). Lignocellulosic flour was obtained by grinding Opuntia Ficus Indica cladodes. PLA/talc/ Opuntia Ficus Indica flour (OFI-F) biocomposites were prepared by melt processing and characterized using Wide-angle X-ray scattering (WAXS) and Scanning Electron Microscope (SEM). The thermal degradation of neat PLA and its biocomposites can be identified quantitatively by solid-state kinetics models. Thermal degradation results on biocomposites compared to neat PLA show that talc particles at 10 wt % into the PLA matrix have a minor impact on the thermal stability of biocomposites. Loading OFI-F and Talc/OFI-F mixture into the PLA matrix results in a decrease in the maximum degradation temperature, which means that the biocomposites have lower thermal stability. The activation energies (Ea) calculated by the Flynn Wall Ozawa (FWO) and Kissinger Akahira Sunose (KAS) model-free approaches and by model-fitting (Kissinger method and Coats-Redfern method) are in good agreement with one another. In addition, in this work, the degradation mechanism of biocomposites is proposed using Coats-Redfern and Criado methods.

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