scholarly journals Spiro-cyclotriphosphazene with three functional end groups: synthesis and structure characterization of new polycyclotriphosphazenes with Schiff-base groups

Polimery ◽  
2021 ◽  
Vol 66 (6) ◽  
pp. 341-349
Author(s):  
Salah Al-Shukri ◽  
Ayad Tarik Mahmood ◽  
Othman A. Al Hanbali
Keyword(s):  
Schiff Base ◽  
Oxygen Index ◽  
Structure Characterization ◽  
Gravimetric Analysis ◽  
Limiting Oxygen Index ◽  
Strong Base ◽  
Good Thermal Stability ◽  
Schiff Base Derivatives ◽  
End Groups

A new tris-spiro-(3,4-dioxybenzaldehyde)cyclotriphosphazene [PNCHO] was synthesized from the condensation of hexachlorocyclotriphosphazene with 3,4-dihydroxybenzaldehyde in the presence of strong base. Further reaction of the trialdehydic cyclotriphosphazene based molecules [PNCHO] with three different dianilines (benzidine, 4,4'-methylenedianiline and 4,4′-Sulfonyldianiline) resulted in creation of a new poly(tris-spiro-3,4-dioxbenzene)cyclotriphosphazenes with Schiff-base groups [PNSB1-3]. The structures of [PNCHO] and the polycyclotriphosphazenes-schiff base derivatives were characterized by means of FTIR, 1H, 13C NMR and C.H.N elemental analysis. Differential scanning calorimetery (DSC) revealed a relatively high glass transition temperature (135−175°C) of obtained polymers. Thermal gravimetric analysis (TGA) exhibited their good thermal stability (up to 375oC). The char yield was about 36-42% at 700°C. All polymers were self-extinguishable as the LOI (Limiting Oxygen Index) values were above 26% and this meets with the V-0 and V-1, classification (UL-94). No fumes, soot, or toxic gases emission were observed during burning. The polymers obtained can be used as environmentally friendly, flame-retardant materials.

scholarly journals An Effective Method for Preparation of Liquid Phosphoric Anhydride and Its Application in Flame Retardant Epoxy Resin

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2205
Author(s):  
Qian Li ◽  
Yujie Li ◽  
Yifan Chen ◽  
Qiang Wu ◽  
Siqun Wang
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Epoxy Resins ◽  
Oxygen Index ◽  
Decomposition Temperature ◽  
Ease Of Use ◽  
Limiting Oxygen Index ◽  
Good Thermal Stability ◽  
Low Viscosity ◽  
The Impact

A novel liquid phosphorous-containing flame retardant anhydride (LPFA) with low viscosity was synthesized from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and methyl tetrahydrophthalic anhydride (MeTHPA) and further cured with bisphenol-A epoxy resin E-51 for the preparation of the flame retardant epoxy resins. Both Fourier transform infrared spectroscopy (FT-IR), mass spectrometry (MS) and nuclear magnetic resonance (NMR) measurements revealed the successful incorporation of DOPO on the molecular chains of MeTHPA through chemical reaction. The oxygen index analysis showed that the LPFA-cured epoxy resin exhibited excellent flame retardant performance, and the corresponding limiting oxygen index (LOI) value could reach 31.2%. The UL-94V-0 rating was achieved for the flame retardant epoxy resin with the phosphorus content of 2.7%. With the addition of LPFA, the impact strength of the cured epoxy resins remained almost unchanged, but the flexural strength gradually increased. Meanwhile, all the epoxy resins showed good thermal stability. The glass transition temperature (Tg) and thermal decomposition temperature (Td) of epoxy resin cured by LPFA decreased slightly compared with that of MeTHPA-cured epoxy resin. Based on such excellent flame retardancy, low viscosity at room temperature and ease of use, LPFA showed potential as an appropriate curing agent in the field of electrical insulation materials.

scholarly journals Influence of the Characteristics of Expandable Graphite on the Morphology, Thermal Properties, Fire Behaviour and Compression Performance of a Rigid Polyurethane Foam

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 168 ◽  
Author(s):  
Pablo Acuña ◽  
Zhi Li ◽  
Mercedes Santiago-Calvo ◽  
Fernando Villafañe ◽  
Miguel Rodríguez-Perez ◽  
...  
Keyword(s):  
Particle Size ◽  
Oxygen Index ◽  
Fire Behavior ◽  
Polyurethane Foams ◽  
Expandable Graphite ◽  
Size Distributions ◽  
Limiting Oxygen Index ◽  
Compression Performance ◽  
Cone Calorimeter Test

Three types of expandable graphite (EG) differing in particle size and expansion volume, are compared as flame retardant additives to rigid polyurethane foams (RPUFs). In this paper we discuss microstructure, thermal stability, fire behavior, and compression performance. We find that ell size distributions were less homogeneous and cell size was reduced. Furthermore, thermal conductivity increased along with EG loading. Thermogravimetric analysis (TGA) showed that EG only increased residue yield differently. The results indicate that a higher expansion of EG increased the limiting oxygen index (LOI) value, whereas a bigger particle size EG improved the rating of the vertical burning test (UL94). Results from the cone calorimeter test showed that a bigger particle size EG effectively reduced peak of heat release rate (pHRR). Furthermore, a higher expansion, led to a decrease in smoke production (TSP). The combination of both characteristics gives extraordinary results. The physical–mechanical characterization of the EG/RPUF foams revealed that their compression performance decreased slightly, mostly due to the effect of a bigger size EG.

scholarly journals Development and Characterization of a Biodegradable Colored Film Based on Starch and Chitosan by Using Acacia Catechu

2016 ◽  
Vol 8 (2) ◽  
pp. 123-130
Author(s):  
FB Quader ◽  
RA Khan ◽  
MA Islam ◽  
S Saha ◽  
KN Sharmin
Keyword(s):  
Tensile Strength ◽  
Composite Film ◽  
Thermo Gravimetric Analysis ◽  
Chitosan Film ◽  
Green Technology ◽  
Gravimetric Analysis ◽  
Good Thermal Stability ◽  
Biodegradable Composite ◽  
Acacia Catechu

Green technology like biodegradable films using natural polymer is an obvious need of today. Attempt of this experiment was aimed at development and characterization of a biodegradable colored film based on starch and chitosan by using Acacia catechu. Chitosan reinforced starch based biodegradable composite film was prepared by casting. The chitosan content in the films was varied from 20-80 % (w/w). Tensile strength (TS) was improved significantly with the addition of chitosan but the elongation at break (EB %) of the composite decreased. With the addition of the Acacia catechu, tensile strength of the composites improved more. The acacia content of the film was varied from 0.05-0.2(w/w). The good thermal stability of this prepared film was confirmed by thermo-gravimetric analysis. Structural characterization was done by Fourier transform infrared radiation spectroscopy. Surface morphology of the composite film was examined by scanning electron microscope (SEM) which suggested sufficient homogenization of starch, chitosan and Acacia catechu. Water uptake was found lower for final composites in the comparison to starch/chitosan and chitosan film. The satisfactory rate of degradation in the soil is expected that the final composite film within less than 6 months. The developed films intended to use as the alternative of synthetic non biodegradable colored packaging films.J. Environ. Sci. & Natural Resources, 8(2): 123-130 2015

Study on the Synthesis and Characterization of a Novel Phosphorus-Nitrogen Containing Intumescent Flame Retardant

2011 ◽  
Vol 399-401 ◽  
pp. 1376-1380
Author(s):  
Li Hua You ◽  
Yin Yin Hui ◽  
Xiang Ning Shi ◽  
Zhi Han Peng
Keyword(s):  
Molecular Structure ◽  
Thermal Properties ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Phosphinic Acid ◽  
Intumescent Flame Retardant ◽  
Synthesis And Characterization ◽  
Limiting Oxygen Index

In this study, a novel phosphorus-nitrogen containing intumescent flame retardant (P-N IFR) poly(melamine 2-carboxyethyl(phenyl) phosphate)(PMCEP) was prepared via the reaction of 2-carboxyethyl (phenyl) phosphinic acid (CEPPA) and melamine (MEL) in two-steps. Meanwhile, the molecular structure of the chemical compound was determined by FTIR,1H-NMR and elemental analysis; and the thermal properties was investigated by means of TGA. Combustion studies revealed high limiting oxygen index (LOI) indicative of better flame-retardancy properties for PBT resin.

Preparation and Characterization of Tetradecanol Microcapsule Phase Change Materials by Emulsion Polymerization

2015 ◽  
Vol 1089 ◽  
pp. 137-141 ◽  
Author(s):  
Xiao Qiu Song ◽  
Long Di Cao ◽  
Dan Dan Xu
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Gravimetric Analysis ◽  
Scanning Calorimetry ◽  
Good Thermal Stability ◽  
Result Show ◽  
Ft Ir ◽  
Latent Heats ◽  
Test Result

In this study, it was aimed at preparing and characterizating of poly (methyl methacrylate) (PMMA) shell microcapsules containing tetradecanol as phase change materials (PCMs) for thermal energy storage. The tetradecanol microcapsules were characterized by using scanning electron microscopy (SEM), fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). The test result show that the contents of tetradecanol in microcapsules nearly 57.5% and the latent heats of melting and freezing were found to be 120.7 and 118.4 J/g. TGA analyses also indicated that the microPCMs degraded in two steps and have good thermal stability.

Optically active polymer: synthesis and characterization of new optically active poly (hydrazide-imide)s incorporating L- leucine

e-Polymers ◽  
2007 ◽  
Vol 7 (1) ◽  
Author(s):  
Abdol Reza Hajipour ◽  
Saeed Zahmatkesh ◽  
Arnold E. Ruoho
Keyword(s):  
Thermo Gravimetric Analysis ◽  
Specific Rotation ◽  
Optically Active ◽  
Gravimetric Analysis ◽  
Optically Active Polymer ◽  
Scanning Calorimetry ◽  
Thermo Gravimetric ◽  
Good Thermal Stability ◽  
H Nmr

AbstractThis paper deals with the polycondensation between a chiral diacyl chloride (N,N′-Pyromelliticdiimido-di-L-leucine chloride) and six different dihydrazides. The corresponding poly (hydrazide-imide)s which have been obtained in quantitative yields are moderately soluble in polar aprotic solvents, have good thermal stability and optical activity. The synthetic compounds have been characterized by IR, UV and 1H NMR spectroscopy, elemental analysis and specific rotation. The thermal properties of the polymers (10 and 15) have been studied by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC).

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