The influence of various/different ratios synthetic fiber mixture on the mechanical, thermal, morphological and flammability properties of poly (lactic acid)/polycarbonate blend

2020 ◽  
pp. 002199832096353
Author(s):  
Seda Hazer ◽  
Ayse Aytac
Keyword(s):  
Lactic Acid ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Control Sample ◽  
Synthetic Fiber ◽  
Poly Lactic Acid ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Limiting Oxygen Index

Poly (Lactic Acid) (PLA)/Polycarbonate (PC) blend has gained much attention as a bio-based polymeric material in various industrial fields. This study aims to improve the properties of PLA/PC blend reinforced with glass fiber (GF) and carbon fiber (CF) mixture to be produced for industrial use. For this purpose, 50PLA/50PC blend was prepared and used as a control sample. Then, 30% by weight CF and 30% GF were added to the matrix separately. To examine the effect of the use of CF and GF together, the composites were prepared as a mixture form of fibers by adding 5-10-15% CF and 5-10-15% GF, respectively, to the control blend in pairs. All composites compounded with the laboratory-scale twin-screw mini extruder and molded by injection molding. The effects of using synthetic fiber mixture were evaluated in terms of the mechanical, thermal and flammability properties. Differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), tensile test, scanning electron microscopy (SEM), limiting oxygen index (LOI), heat release rate (HRR) test were carried for the characterization of composites. The highest tensile strength values ​​and maximum % crystallinity values were obtained for the 15CF/15GF fiber mixture containing PLA/PC composite as 113.7 MPa and 21.4, respectively. CO yield (COY), HRR, and total heat release rate were reduced significantly by using synthetic fibers and fiber mixture.

scholarly journals Preparation of γ-Divinyl-3-Aminopropyltriethoxysilane Modified Lignin and Its Application in Flame Retardant Poly(lactic acid)

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1505 ◽  
Author(s):  
Yan Song ◽  
Xu Zong ◽  
Nan Wang ◽  
Ning Yan ◽  
Xueying Shan ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Heat Release ◽  
Flame Retardant ◽  
Heat Release Rate ◽  
Flame Retardancy ◽  
Release Rate ◽  
Poly Lactic Acid ◽  
Modified Lignin ◽  
Thermal Stability Of

Lignin can be a candidate as a charring agent applied in halogen-free flame retardant polymers, and incorporation of silicon and nitrogen elements in lignin can benefit to enhancing its thermal stability and charring ability. In the present work, wheat straw alkali lignin (Lig) was modified to incorporate silicon and nitrogen elements by γ-divinyl-3-aminopropyltriethoxysilane, and the modified lignin (CLig) was combined with ammonium polyphosphate (APP) as intumescent flame retardant to be applied in poly(Lactic acid) (PLA). The flame retardancy, combustion behavior and thermal stability of PLA composites were studied by the limited oxygen index (LOI), vertical burning testing (UL-94), cone calorimetry testing (CCT) and thermogravimetric analysis (TGA), respectively. The results showed a significant synergistic effect between CLig and APP in flame retarded PLA (PLA/APP/CLig) occured, and the PLA/APP/CLig had better flame retardancy. CCT data analysis revealed that CLig and APP largely reduced the peak heat release rate (PHRR) and total heat release rate (THR) of PLA, indicating their effectiveness in decreasing the combustion of PLA. TGA results exhibited that APP and CLig improved the thermal stability of PLA at high temperature. The analysis of morphology and structure of residual char indicated that a continuous, compact and intumescent char layer on the material surface formed during firing, and had higher graphitization degree. Mechanical properties data showed that PLA/APP/CLig had higher tensile strength as well as elongation at break.

Synthesis of a phosphorus–nitrogen-containing flame retardant and its application in epoxy resin

2018 ◽  
Vol 31 (2) ◽  
pp. 186-196 ◽  
Author(s):  
Shuang Yang ◽  
Yefa Hu ◽  
Qiaoxin Zhang
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Heat Release Rate ◽  
Flame Retardancy ◽  
Release Rate ◽  
Epoxy Resins ◽  
Proton Nuclear Magnetic Resonance ◽  
Scanning Calorimetry ◽  
Cone Calorimeter Test

In this article, a phosphorus–nitrogen-containing flame retardant (DOPO-T) was successfully synthesized by nucleophilic substitution reaction between 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and cyanuric chloride. The chemical structure of DOPO-T was characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance (NMR) and phosphorous-31 NMR, and elemental analysis. DOPO-T was then blended with diglycidyl ether of bisphenol-A to prepare flame-retardant epoxy resins. Thermal properties, flame retardancy, and combustion behavior of the cured epoxy resins were evaluated by differential scanning calorimetry, thermogravimetric analysis, limited oxygen index (LOI) measurement, UL94 vertical burning test, and cone calorimeter test. The results indicated that the glass transition temperature ( Tg) and temperature at 5% weight loss of epoxy resin (EP)/DOPO-T thermosets were gradually decreased with the increasing content of DOPO-T. DOPO-T catalyzed the decomposition of EP matrix in advance. The flame-retardant performance of EP thermosets was significantly enhanced with the addition of DOPO-T. EP/DOPO-T-0.9 sample had an LOI value of 36.2% and achieved UL94 V-1 rating. In addition, the average of heat release rate, peak of heat release rate, average of effective heat of combustion, and total heat release (THR) of EP/DOPO-T-0.9 sample were decreased by 32%, 48%, 23%, and 31%, respectively, compared with the neat EP sample. Impressively, EP/DOPO-T thermosets acquired excellent flame retardancy under low loading of flame retardant.

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 A Study of the Thermal Degradation and Combustion Characteristics of Some Materials Commonly Used in the Construction Sector

Polymers ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 1833 ◽  
Author(s):  
Javier Arturo Piedrahita Solorzano ◽  
Khalid Abu Mohammad Moinuddin ◽  
Svetlana Tretsiakova-McNally ◽  
Paul Joseph
Keyword(s):  
Thermal Degradation ◽  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Inner Core ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
Combustion Heat ◽  
Internal Core ◽  
Combustion Flow

In the present work, some materials that are commonly used in the construction industry were studied with regard to their thermal degradation characteristics and combustion attributes. These included façade materials for pre-fabricated houses, such as the layers of cross-laminated timber (CLT) and the inner core of aluminium composite panels (ACPs). The relevant investigations were carried out by employing thermo-gravimetric analysis (TGA) and pyrolysis combustion flow calorimetry (PCFC). The Arrhenius parameters and the associated calorimetric quantities, i.e., heat release rates, temperature to the peak heat release rate, heats of combustion, heat release capacities, and char yields, were also evaluated. These parameters showed that CLT is more fire retarded than the polymeric internal core of ACP façade materials. Furthermore, some valuable correlations among the various test quantities were found. For instance, a good correlation exists between the general profiles of the thermograms obtained through TGA runs and the heat release rate (HRR) traces from PCFC measurements. Depending on the nature of the materials, the char yields measured by PCFC can be 4–20 times higher than the ones obtained through TGA.

scholarly journals Investigations of the Montmorillonite and Aluminium Trihydrate Addition Effects on the Ignitability and Thermal Stability of Asphalt

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Kai Zhu ◽  
Ke Wu ◽  
Bin Wu ◽  
Zhiyi Huang
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cone Calorimeter ◽  
Oxygen Index ◽  
Limiting Oxygen Index ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
Thermal Stability Of

By means of limiting oxygen index (LOI), cone calorimeter, and TG-DSC tests, this paper investigated the effect of unmodified montmorillonite (MMT), organically modified montmorillonite (OMMT), and aluminium trihydrate (ATH) additions on the flame retardancy for asphalt combustion. Experimental results showed that adding a small amount of montmorillonite did not significantly increase the oxygen index of the asphalt but reduced the heat release rate during asphalt combustion. TGA tests had indicated that the montmorillonite (MMT and OMMT) could suppress the release of flammable volatiles and form more asphaltenes, which hence postponed the burnout time of asphalt. Furthermore, the combination of montmorillonite (MMT and OMMT) and ATH had yielded a synergistic effect, which had further reduced the heat release rate and also increased the oxygen index of asphalt. In particular, after further addition of OMMT, the barrier layer showed less crack, leading to a significant decrease in the heat release rate as compared to the adding of ATH alone.

The synergistic flame retardancy of modified expandable graphite and metal hydroxides on HDPE/EVA composites

2020 ◽  
pp. 089270572092513
Author(s):  
Xincheng Guo ◽  
Nian Liu ◽  
Lingtong Li ◽  
Zhuyu Bai ◽  
Xiaolang Chen ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardancy ◽  
Synergistic Effects ◽  
Zinc Borate ◽  
Expandable Graphite ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Limiting Oxygen Index ◽  
Cone Calorimeter Test ◽  
Ul 94

In this article, the flammable behaviors and synergistic effects of modified expanded graphite (MEG) with zinc borate (ZB) on flame-retardant high-density polyethylene/ethylene vinyl acetate (HDPE/EVA) composites containing magnesium hydroxide (MH) and aluminum hydroxide (ATH) are investigated by the Underwriters Laboratories-94 (UL-94) test, limiting oxygen index (LOI), cone calorimeter test (CCT), thermal gravimetric analysis (TGA), Fourier transform infrared (FTIR), differential scanning calorimetry, and tensile tests. The LOI, UL-94, and CCT results show that the synergistic effect of MEG and ZB can improve the flame retardancy of the composites. With the addition of ZB and MEG, the LOI value increases, and the UL-94 reaches the V-0 rating. The heat release rate and total heat release decrease, respectively. The data obtained from the TGA indicate that the synergistic effects of ZB with MEG increase the decomposition temperature when 2 phr ZB and 8 phr MEG are added into the composites. The data from FTIR show that HMEG8 and HMEG10 composites produce phosphate at high temperatures, which promotes the formation of stable and compact charred layer. All the results show that ZB and MEG have positive synergistic effects on HDPE/EVA composites containing MH and ATH. However, ZB and MEG play a negative role in the tensile properties of the HDPE/EVA composites.

Flame-retardant mechanism of zinc borate and magnesium hydroxide in aluminum hypophosphite–based combination for TPE-S composites

2019 ◽  
Vol 37 (3) ◽  
pp. 273-300 ◽  
Author(s):  
Xi Cheng ◽  
Jianming Wu ◽  
Chenguang Yao ◽  
Guisheng Yang
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Magnesium Hydroxide ◽  
Gaseous Phase ◽  
Release Rate ◽  
Zinc Borate ◽  
Limiting Oxygen Index ◽  
Melamine Cyanurate ◽  
Phenylene Oxide ◽  
Aluminum Hypophosphite

Aluminum hypophosphite combined with melamine cyanurate and poly(phenylene oxide) was applied to flame retard TPE-S system (blends of SEBS and polyolefin). TPE-S containing 16 wt% aluminum hypophosphite, 20 wt% melamine cyanurate, and 10 wt% poly(phenylene oxide) pass a V-0 rating in the UL-94 test and its limiting oxygen index value is 28.2%. Zinc borate and magnesium hydroxide were added to modify the AHP/MCA/PPO formulation. Thermogravimetric–Fourier transform infrared analysis tests showed that aluminum hypophosphite and melaminecyanurate acted in gaseous phase while aluminum hypophosphite and poly(phenylene oxide) helped to form char residue. TPE-S/AHP/MCA/PPO significantly decreased the heat release rate (reduction in peak heat release rate from 2001 to 494 kW m−2). Scanning electron microscopy/energy dispersive spectrometry results demonstrated that zinc borate and magnesium hydroxide promoted to retain more P and O elements in residue. Zinc borate and magnesium hydroxide in AHP/MCA/PPO formulation enhanced the char formation and reduced gas evolution of TPE-S, thus deteriorating the combination between gaseous phase and condensed phase.

scholarly journals Effect of Magnesium Hydroxide and Aluminum Hydroxide on the Thermal Stability, Latent Heat and Flammability Properties of Paraffin/HDPE Phase Change Blends

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 180 ◽  
Author(s):  
Ru Zhou ◽  
Zhuang Ming ◽  
Jiapeng He ◽  
Yanming Ding ◽  
Juncheng Jiang
Keyword(s):  
Thermal Stability ◽  
Phase Change ◽  
Heat Release ◽  
Flame Retardant ◽  
Latent Heat ◽  
Aluminum Hydroxide ◽  
Heat Release Rate ◽  
Magnesium Hydroxide ◽  
Release Rate ◽  
Gravimetric Analysis

In this study, paraffin was selected as the phase change material (PCM) and high-density polyethylene (HDPE) as the supporting material to prepare a flame-retardant PCM system. The system consisted of paraffin, HDPE, expanded graphite (EG), magnesium hydroxide (MH) and aluminum hydroxide (ATH). The thermal stability and flame retardancy were studied by thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM) and cone calorimeter test (CONE). The SEM proved that the addition of MH and ATH can produce an oxide film on the surface of the composite material and form a “physical barrier” with the char layer, generated by the expansion of EG, preventing the transfer of heat and oxygen. The TGA test showed that, compared with other flame-retardant systems, the materials with added MH and ATH have a higher thermal stability and carbonization ability, and the amount of char residue has increased from 17.6% to 32.9%, which reduces the fire risk of the material. The flame retardant effect is obvious. In addition, the addition of MH and ATH has no significant effect on the phase transition temperature and latent heat value of PCMs. The CONE data further confirmed that MH and ATH can work with EG to prevent heat release, reduce the total heat release rate (THR) value and effectively suppress the generation of smoke, CO and CO2. The peak heat release rate (PHRR) value also decreased, from 1570.2 kW/m2 to 655.9 kW/m2.

Emerging advancements in flame retardancy of polypropylene nanocomposites

2020 ◽  
pp. 089270572093078 ◽  
Author(s):  
Christopher Igwe Idumah
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Mass Loss Rate ◽  
Limiting Oxygen Index ◽  
Market Structures ◽  
Rapid Decomposition ◽  
Total Mass Loss ◽  
Recent Developments ◽  
Scope Of Application

Polypropylene (PP) burns very rapidly due to its wholly aliphatic hydrocarbon structure. Studies have shown that the rapid decomposition and flammability of PP are very high when compared with wood and other cellulosic materials. This has limited the application of PP and necessitated the need to inculcate flame-retardant (FR) behaviour to PP to further widen its scope of application especially in areas where FR is paramount. With the advent of nanotechnology, increasing inclusion of FR nanofillers in PP has demonstrated propensity to repressing critical flammability parameters such as heat release rate, peak of heat release rate, rate of carbon monoxide production, smoke production rate and total mass loss rate while simultaneously increasing limiting oxygen index, time of ignition and total peak of heat release rate. This efficiently represses PP flammability and provides greater opportunity to minimize loss and risks to life in actual fire scenario through creation of equal layers of carbonaceous char in the condensed phase capable of suppressing the thermal decomposition caused by oxygen and heat to PP matrix, thus effectively cutting-off the fire path. This article reviews recent developments in FR of PP composites, nanocomposites and nano-biocomposites. Market structures are also presented.

scholarly journals Nonisothermal Cold Crystallization Kinetics of Poly(lactic acid)/Bacterial Poly(hydroxyoctanoate) (PHO)/Talc

2019 ◽  
Vol 17 (1) ◽  
pp. 1266-1278
Author(s):  
Omaima Alhaddad ◽  
Safaa H. El-Taweel ◽  
Yasser Elbahloul
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Crystallization Kinetics ◽  
Crystallization Rate ◽  
Cold Crystallization ◽  
Poly Lactic Acid ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Kinetics Of ◽  
Thermal Stability Of

AbstractThe effects of bacterial poly(hydroxyoctanoate) (PHO) and talc on the nonisothermal cold crystallization behaviours of poly(lactic acid) (PLA) were analysed with differential scanning calorimetry (DSC), and the thermal stability of the samples was observed with thermal gravimetric analysis (TGA). The modified Avrami’s model was used to describe the nonisothermal cold crystallization kinetics of neat PLA and its blends. The activation energies E for nonisothermal cold crystallization were calculated by the isoconversional method of Kissinger-Akahira-Sunose (KAS). The DSC results showed that the PLA/PHO blends were immiscible in the whole studied range, and as the PHO and talc content increased, the crystallization rate of PLA accelerated, and the crystallinity of PLA in the PLA samples increased. The values of the Avrami exponent indicated that the nonisothermal cold crystallization of the neat PLA and its blends exhibited heterogeneous, three-dimensional spherulitic growth. The E values were strongly dependent on PHO and talc. The TGA results showed that the presence of PHO and talc slightly influenced the thermal stability of PLA.

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