Flammability and thermal properties of modified carbon nanotubes in poly(lactic acid)

2018 ◽  
Vol 32 (8) ◽  
pp. 1107-1122 ◽  
Author(s):  
Chao Guo ◽  
Fei Xin ◽  
Congcong Zhai ◽  
Yu Chen
Keyword(s):  
Carbon Nanotubes ◽  
Lactic Acid ◽  
Flame Retardancy ◽  
Mass Loss Rate ◽  
Covalent Bond ◽  
Poly Lactic Acid ◽  
Cone Calorimetry ◽  
Limiting Oxygen Index ◽  
Multi Walled Carbon Nanotubes ◽  
Modified Carbon Nanotubes

The multi-walled carbon nanotubes (CNTs) were modified using phosphaphenanthrene compounds (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)) and vinyl triethoxy silane (VTES) by covalent bond. The DOPO- and VTES-treated CNTs were named DVCNT, and the structure was characterized by Fourier transform infrared, thermogravimetric analysis, and transmission electron microscopy. Nanocomposites were prepared by adding CNTs or DVCNT to poly(lactic acid) (PLA), and the flame retardancy was examined by determination of limiting oxygen index (LOI), vertical burning (UL94), and cone calorimetry. Results reveal that the LOI of PLA/DVCNT_4% composites was increased to 26.6 and prevents dripping of PLA in some level, and DVCNT can significantly reduce heat release rate and mass loss rate during combustion, which indicate that DVCNT can improve the dispersibility of the CNTs in the polymer composites and hence enhance the flame retardancy simultaneously.

The Influence of Carbon Nanotubes Contents on Electrical and Flammability Properties of Poly(Lactic Acid)/Multiwalled Carbon Nanotubes Nanocomposites

2017 ◽  
Vol 268 ◽  
pp. 365-369
Author(s):  
Mohd Shaiful Zaidi Mat Desa ◽  
Azman Hassan ◽  
Agus Arsad
Keyword(s):  
Carbon Nanotubes ◽  
Electrical Conductivity ◽  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Melt Blending ◽  
Multiwalled Carbon ◽  
Limiting Oxygen Index ◽  
Blending Method ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

The effects of carboxylic functionalized multi-walled carbon nanotubes (CNT) contents on electrical and flammability properties of poly(lactic) acid/CNT nanocomposites were investigated. The PLA/CNT nanocomposites were prepared by melt-blending method, where the CNT contents were varied from 1 to 9 phr. From flammability properties analysis, nanocomposites with 9 phr CNT showed the highest limiting oxygen index (LOI) of 26.5 vol% as compared to 19.5 vol% of neat PLA. All nanocomposites with higher than 5 phr CNT contents also passed the V0 class of UL-94 vertical burning test rating. The direct current electrical test revealed that the electrical conductivity increases by approximately seven orders of magnitude from 2.19 × 10-11 S/m of neat PLA to 2.00 × 10-4 S/m for PLA/CNT nanocomposites with 5 phr CNT contents. The electrical conductivity of PLA/CNT continues to increase beyond 5 phr contents, with 2.26 × 10-3 S/m and 4.29 × 10-3 S/m respectively for 7 and 9 phr contents. The good dispersion of CNT leads to formation of electron conducting CNT networks throughout the insulating PLA matrix.

Preparation of lignin–silica hybrids and its application in intumescent flame-retardant poly(lactic acid) system

2012 ◽  
Vol 24 (8) ◽  
pp. 738-746 ◽  
Author(s):  
Rui Zhang ◽  
Xifu Xiao ◽  
Qilong Tai ◽  
Hua Huang ◽  
Jian Yang ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Lactic Acid ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Photoelectron Spectroscopy ◽  
Intumescent Flame Retardant ◽  
Poly Lactic Acid ◽  
Limiting Oxygen Index ◽  
Silica Hybrids ◽  
Thermal Stability Of

Lignin–silica hybrids (LSHs) were prepared by sol–gel method and characterized by Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). LSH and ammonium polyphosphate (APP) were added into poly(lactic acid) (PLA) as a novel intumescent flame-retardant (IFR) system to improve the flame retardancy of PLA. The flame-retardant effect of APP and LSH in PLA was studied using limiting oxygen index (LOI), vertical burning (UL-94) tests and cone calorimeter. The thermal stability of PLA/APP/LSH composites was evaluated by thermogravimetric analysis (TGA). Additionally, the morphology and components of char residues of the IFR-PLA composites were investigated by SEM and XPS. With the addition of APP/LSH to PLA system, the morphology of the char residue has obviously changed. Compared with PLA/APP and PLA/APP/lignin, a continuous and dense intumescent charring layer with more phosphor in PLA composites is formed, which exhibits better flame retardancy. All the results show that the combination of APP and LSH can improve the flame-retardant property and increase the thermal stability of PLA composites greatly.

Functionalization of Graphene and Its Influence on Mechanical Properties and Flame Retardancy of Jute/Poly(lactic acid) Composite

2019 ◽  
Vol 19 (11) ◽  
pp. 7074-7082 ◽  
Author(s):  
Tao Yu ◽  
Changqing Hu ◽  
Yan Li
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Flame Retardancy ◽  
Photoelectron Spectroscopy ◽  
Oxygen Index ◽  
Poly Lactic Acid ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
Matrix Toughness ◽  
Modified Graphene

In this work, 9,10-dihydro-9-oxa-phosphaphenanthrene-10-oxide (DOPO) was covalently grafted onto the surface of graphene to get modified graphene (G-DOPO) firstly. The mechanical properties and flame retardancy of jute/poly(lactic acid) (PLA) composite with G-DOPO were studied. According to Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS), it was confirmed that DOPO was grafted on the surface of graphene successfully. Thermogravimetric analysis (TGA) results demonstrated that the residue char of the composites increased with the addition of G-DOPO. The total heat release (THR) of the composite was significantly reduced and the limiting oxygen index (LOI) increased after adding G-DOPO into the composite. Moreover, the mechanical properties results showed that the comprehensive effects of G-DOPO on the interface enhancement and matrix toughness were found.

Development, optimization, and characterization of electrospun poly(lactic acid) nanofibers containing multi-walled carbon nanotubes

2007 ◽  
Vol 105 (3) ◽  
pp. 1668-1678 ◽  
Author(s):  
Seth D. McCullen ◽  
Kelly L. Stano ◽  
Derrick R. Stevens ◽  
Wesley A. Roberts ◽  
Nancy A. Monteiro-Riviere ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Lactic Acid ◽  
Poly Lactic Acid ◽  
Multi Walled Carbon Nanotubes ◽  
Walled Carbon Nanotubes

scholarly journals Effects of Graphene Nanoplatelets and Multiwall Carbon Nanotubes on the Structure and Mechanical Properties of Poly(lactic acid) Composites: A Comparative Study

2019 ◽  
Vol 9 (3) ◽  
pp. 469 ◽  
Author(s):  
Todor Batakliev ◽  
Ivanka Petrova-Doycheva ◽  
Verislav Angelov ◽  
Vladimir Georgiev ◽  
Evgeni Ivanov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Lactic Acid ◽  
Low Cost ◽  
Multiwall Carbon Nanotubes ◽  
Poly Lactic Acid ◽  
Carbon Filler ◽  
Multi Walled Carbon Nanotubes ◽  
Carbon Fillers ◽  
Walled Carbon Nanotubes

Poly(lactic acid)/graphene and poly(lactic acid)/carbon nanotube nanocomposites were prepared by an easy and low-cost method of melt blending of preliminary grinded poly(lactic acid) (PLA) with nanosized carbon fillers used as powder. Morphological, structural and mechanical properties were investigated to reveal the influence of carbon nanofiller on the PLA–based composite. The dependence of tensile strength on nanocomposite loading was defined by a series of experiments over extruded filaments using a universal mechanical testing instrument. The applying the XRD technique disclosed that compounds crystallinity significantly changed upon addition of multi walled carbon nanotubes. We demonstrated that Raman spectroscopy can be used as a quick and unambiguous method to determine the homogeneity of the nanocomposites in terms of carbon filler dispersion in a polymer matrix.

scholarly journals Mechanical and flammability properties of poly(lactic acid)/poly(butylene adipate-co-terephthalate) blends and nanocomposites: Effects of compatibilizer and graphene

2018 ◽  
Vol 14 (4) ◽  
pp. 425-431 ◽  
Author(s):  
Nilesh Kumar Shrivastava ◽  
Ooi Shu Wooi ◽  
Azman Hassan ◽  
Ibrahim Mohammed Inuwa
Keyword(s):  
Lactic Acid ◽  
Impact Strength ◽  
Flame Retardancy ◽  
Testing Machine ◽  
High Strength ◽  
Poly Lactic Acid ◽  
Limiting Oxygen Index ◽  
Morphological Studies ◽  
Impact Tester ◽  
Ul 94

Poly(lactic acid) (PLA)/polybutylene adipate co-terephthalate (PBAT) blends were prepared by melt blending and compatibilized by glycidyl methacrylate (GMA). The effect of graphene nanoplatelets (GNP) on these compatibilized blends were investigated by incorporating GNP at different content. The formulated blend and nanocomposites were characterized for mechanical, morphological, thermal and flammability properties by using universal testing machine, impact tester, field emission scanning electron microscope (FESEM), x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), limiting oxygen index (LOI) and UL-94 respectively. The incorporation of 8 phr GMA into PLA/PBAT (75:25) blend as a compatibilizer results in a significant increase in impact strength (more than 14 times higher) compared to the uncompatibilized blend. Young's modulus and tensile strength of compatibilized PLA/PBAT nanocomposites increased upon addition of GNP and reached maximum values at 4 phr before decreasing slightly. However, impact strength decreased with increasing GNP contents. The thermal stability and the flame retardancy of the GNP reinforced blend nanocomposites were also improved with an increase in nanofiller content and the maximum values for the nanocomposites were achieved at 6 phr. Interestingly, the nanocomposites samples showed a UL-94 rating of V0 at 4 and 6 phr of GNP. Morphological studies using FESEM showed the GNP were evenly distributed and dispersed in the PLA/PBAT nanocomposites. The current methodology to prepare PLA/PBAT blend nanocomposite is an economical way to produce high strength biodegradable polymer which also has good flame retardancy.

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