Krishna Pratap Singh; Anuradha Mishra; Nand Kumar; Trilok Chand Shami
Abstract
Different types of functionalized thermoplastic polyphosphazenes such as poly(bis(furfuroxy)phosphazenes) (PBFP), poly(bis(1-adamantanemethylamine)phosphazenes) (PBAP) and poly(bis(cyanophenoxy)phosphazenes) (PBCP) were synthesized and further characterized to study their flame retardant properties. ...
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Different types of functionalized thermoplastic polyphosphazenes such as poly(bis(furfuroxy)phosphazenes) (PBFP), poly(bis(1-adamantanemethylamine)phosphazenes) (PBAP) and poly(bis(cyanophenoxy)phosphazenes) (PBCP) were synthesized and further characterized to study their flame retardant properties. Structural characterizations were carried out by using GPC, FTIR, 1 H & 31 P NMR and wide angle XRD. Beside this, the solubility behaviour of these synthesized polyphosphazenes was checked in various protic and aprotic solvents. Thermal analysis and combustion properties of synthesized polyphosphazenes were investigated using thermogravimetric analysis (TGA), differential scanning calorimetry, UL-94 (vertical burning test) and cone calorimetry. The Limiting Oxygen Index values of synthesized polyphosphazenes were also determined from their % char yield obtained in TGA. It was found that the LOI value was highest for PBCP and lowest for PBAP amongst all substituted polyphosphazenes. Further, all the polymeric samples showed high flame retardancy with UL-94 V-0 rating. The water uptake property of synthesized polyphosphazene polymers was also invested by measuring their water contact angles which showed that all the polymers were hydrophobic in nature with their water contact angles in the range of 137 o to 141 o . Copyright © VBRI Press.
Reena Singhal; Arun Kumar Nagpal
Abstract
In the present study five blends of Diglycidyl ether of bisphenol-A and thiol terminated liquid polysulfide with varying amount of polysulfide (i.e. 10 to 50 phr) were synthesized by physical mixing at 90 o C and synthesized blends were cured with phthalic anhydride. Interaction among epoxide group of ...
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In the present study five blends of Diglycidyl ether of bisphenol-A and thiol terminated liquid polysulfide with varying amount of polysulfide (i.e. 10 to 50 phr) were synthesized by physical mixing at 90 o C and synthesized blends were cured with phthalic anhydride. Interaction among epoxide group of DGEBA, -SH group of polysulfide and anhydride group of curing agent discussed through FT-IR analysis. The TGA studies revealed a decrease in thermal stability and activation energy (114.35 - 73.04 kJ/mole) with increase in polysulfide content. Volume resistivity decreases from 5.34 × 10 15 to 3.83 × 10 11 ohm-cm with increase in polysulfide content in the blends. The study of chemical resistance for various acids, alkalies to distilled water, sea water, xylene, ethanol, methyl ethyl ketone and acetone indicated that chemical resistance of blends decreased with increase in polysulfide content. Scanning electron microscopy (SEM) indicated the presence of two-phase morphology in the blends.
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