scholarly journals Combination of Corn Pith Fiber and Biobased Flame Retardant: A Novel Method toward Flame Retardancy, Thermal Stability, and Mechanical Properties of Polylactide

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1562
Author(s):  
Yunxian Yang ◽  
De-Yi Wang ◽  
Laia Haurie ◽  
Zhiqi Liu ◽  
Lu Zhang

Some crop by-products are considered to be promising materials for the development of novel biobased products for industrial applications. The flammability of these alternatives to conventional materials is a constraint to expanded applications. Polylactide (PLA) composites containing a combination of oxidized corn pith fiber (OCC) and a biobased flame retardant (PA-THAM) have been prepared via an in situ modification method. SEM/EDS, FTIR and TGA were performed to establish that PA-THAM was coated onto the surface of OCC. The mechanical properties, thermal stability and fire behavior of PLA-based biocomposites were investigated. The incorporation of 5 phr PA-THAM imparted biocomposite good interfacial adhesion and increased decomposition temperature at 10% mass loss by 50 °C. The flame retardant properties were also improved, as reflected by an increased LOI value, a UL-94 V-2 rating, reduction of PHRR, and increased formation of char residue. Therefore, the introduction of 5 phr PA-THAM can maintain a good balance between flame retardancy and mechanical properties of this PLA/OCC system.

2021 ◽  
Author(s):  
Yajun Chen ◽  
Jingxiu He ◽  
Zhe Sun ◽  
Bo Xu ◽  
Juan Li ◽  
...  

Abstract Cellulose nanocrystals (CNCs) have been used as bio-based carbon source in intumescent system. However, CNCs have the disadvantages of low onset decomposition temperature and decompose and carbonize during processing. We, herein, demonstrated the design of phosphazene-containing CNCs (P/N-CNCs) with great thermal stability and outstanding charring ability. The TGA results showed that the initial decomposition temperature of P/N-CNCs was increased from 202.4 ℃ to 272.2 ℃ (increased by 34.5%), and the residual char at 700 ℃ was increased from 24.9 wt% to 55.8 wt% compared with CNCs. Then, flame retardant PLA composites were prepared by blending PLA, P/N-CNCs with ammonium polyphosphate (APP), melamine (MPP), aluminum hypophosphite (AHP) and piperazine pyrophosphate (PPAP), respectively. The thermal stability, flame retardant properties and mechanical properties of PLA composites were investigated. The results showed that the flame retardant system constructed by 7 wt% APP and 3 wt% P/N-CNCs had the best effect in PLA. PLA/7APP/3P/N-CNCs had the highest limit oxygen index value (28.1%), the lowest peak heat release rate (266 kW/m2) and reached UL 94 V-0 rating. Moreover, the tensile strength, impact strength and elongation at break of PLA/7APP/3P/N-CNCs were increased by 7.3%, 18.6% and 29.4%, respectively, compared with these properties of PLA/7APP/ 3CNCs. This work provides a new idea for the design of CNCs with great thermal stability and outstanding charring ability, and offers a new method for the preparation of high-performance flame-retardant PLA composites.


Materials ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1251
Author(s):  
Yilin Liu ◽  
Bin Li ◽  
Miaojun Xu ◽  
Lili Wang

Ethylene vinyl acetate (EVA) copolymer has been used extensively in many fields. However, EVA is flammable and releases CO gas during burning. In this work, a composite flame retardant with ammonium polyphosphate (APP), a charring–foaming agent (CFA), and a layered double hydroxide (LDH) containing rare-earth elements (REEs) was obtained and used to improve the flame retardancy, thermal stability, and smoke suppression for an EVA matrix. The thermal analysis showed that the maximum thermal degradation temperature of all composites increased by more than 37 °C compared with that of pure EVA. S-LaMgAl/APP/CFA/EVA, S-CeMgAl/APP/CFA/EVA, and S-NdMgAl/APP/CFA/EVA could achieve self-extinguishing behavior according to the UL-94 tests (V-0 rating). The peak heat release rate (pk-HRR) indicated that all LDHs containing REEs obviously reduced the fire strength in comparison with S-MgAl. In particular, pk-HRR of S-LaMgAl/APP/CFA/EVA, S-CeMgAl/APP/CFA/EVA and S-NdMgAl/APP/CFA/EVA were all decreased by more than 82% in comparison with pure EVA. Furthermore, the total heat release (THR), smoke production rate (SPR), and production rate of CO (COP) also decreased significantly. The average mass loss rate (AMLR) confirmed that the flame retardant exerted an effect in the condensed phase of the composites. Meanwhile, the combination of APP, CFA, and LDH containing REEs allowed the EVA matrix to maintain good mechanical properties.


RSC Advances ◽  
2015 ◽  
Vol 5 (123) ◽  
pp. 101480-101486 ◽  
Author(s):  
Song Li ◽  
Hongxia Yan ◽  
Shuyao Feng ◽  
Song Niu

A novel reactive phosphorus-containing flame retardant was synthesized and used to modify bismaleimide resin. According to investigations, the modified bismaleimide resin has good mechanical properties, thermal stability and flame retardancy.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Ming-Yuan Shen ◽  
Chen-Feng Kuan ◽  
Hsu-Chiang Kuan ◽  
Chia-Hsun Chen ◽  
Jia-Hong Wang ◽  
...  

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.


2014 ◽  
Vol 67 (11) ◽  
pp. 1688 ◽  
Author(s):  
Jinyun Zheng ◽  
Yujian Yu ◽  
Lulu Zhang ◽  
Xiaomin Zhen ◽  
Yufen Zhao

Two novel types of phosphate derivatives of phosphaphenanthrene with a high phosphorus content were prepared by phosphorylation reaction between either 2-(6-oxido-6H-dibenz<c,e><1,2>oxaphosphorin-6-yl)-methanol (ODOPM) or 2-(6-oxido-6H-dibenz<c,e><1,2>oxaphosphorin-6-yl)-1,4-benzenediol (ODOPB) and dialkyl phosphoryl chloride. The structures of all compounds were characterised by 1H NMR, 13C NMR, 31P NMR, Fourier transform infrared spectroscopy, and high-resolution mass spectrometry. The thermal stability of representative compounds was determined by thermal gravimetric analysis and differential scanning calorimetry. The results showed that the compounds have excellent resistance to oxidation, high thermal stability with an onset decomposition temperature above 200°C, and a high char yield over 25 %, owing to the high P content. The representative compound was added to conventional electrolytes of lithium-ion batteries as flame retardant additive, and the self-extinguishing time and ionic conductivity were measured. The result showed that the compounds have effective flame retardant properties.


2022 ◽  
Vol 2160 (1) ◽  
pp. 012031
Author(s):  
Xiangdong Zhu ◽  
Yijun Chen ◽  
Chongguang Zang

Abstract In this study, to improve the flame retardancy properties of polypropylene, DBDPE/Sb2O3 and DBDPE/HBCD/Sb2O3 flame retardant systems were used for flame retardant PP, and a halogen-free flame retardant PP material was prepared using the one-component intumescent flame retardant PNP1D. Tensile tests, impact tests, ultimate oxygen index, UL94V-0 vertical combustion, thermogravimetric analysis, rheological analysis and scanning electron microscopy were used to study the flame retardant properties and mechanical properties of the flame retardant PP. The test results show that both the ultimate oxygen index of DBDPE/Sb2O3 compounded flame retardant PP and the ultimate oxygen index of PNP1D flame retardant PP are nearly double that of pure PP, passing the UL-94V-0 flame retardant standard. The thermal decomposition temperature range of DBDPE/Sb2O3 compounded system and the thermal decomposition temperature range of PNP1D flame retardant PP both completely cover the thermal decomposition temperature range of both the DBDPE/Sb2O3 compound system and PNP1D flame retardant PP completely covered the thermal decomposition temperature range of pure PP. The tensile and impact strength of the DBDPE/Sb2O3 flame retardant system with 10% SK-80 is 50% higher than that of the DBDPE/Sb2O3 flame retardant system without SK-80. The modified PP with 25% PNP1D is nearly 1 time higher than pure PP in terms of carbon formation and has an ideal flame retardant effect.


2011 ◽  
Vol 236-238 ◽  
pp. 482-485 ◽  
Author(s):  
Ru Lin Fu ◽  
Xian Su Cheng

A novel intumescent flame retardant (IFR), melamine modified enzymatic hydrolysis lignin (MEHL), was synthesized and well characterized by FTIR and TGA. The results showed that the decompose temperature of MEHL is much higher than that of enzymatic hydrolysis lignin (EHL). In order to improve flame retardancy and dripping resistance of EPDM, MEHL and microencapsulated red phosphorus (MRP) were added into EPDM as IFR system. The flame ability and thermal stability of IFR and EPDM composites were investigated by UL-94 vertical burning test and LOI measurements. The results indicated that FV-0 was reached and the LOI value was 35 when per hundred rubber (phr) together with 12 phr MRP and 50 phr EHLM were added. SEM photos showed that the char residue was continuous, and a barrier between flame and rubber was formed, while there were also small holes in its surfaces. On all accounts, EHL used as a carbonization agent instead of petroleum chemicals, such as pentaerythritol, was more environmental friendly and beneficial to economy.


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