The in-situ reaction of hexachlorocyclotriphosphazene with (2- and 4- hydroxyaniline)‎ in the presence of 25 mole percent epoxidized natural rubber

الملخص EN

In this study, the entrapment of 25 mole percent epoxidized natural rubber (ENR-25) within the matrix of organocyclotriphosphazene has been explored.

Two different matrices, tight and loose were prepared via a one-step condensation polymerization of hexachlorocyclotriphosphazene (CTP) with 2-hydroxyaniline (o-aminophenol) or 4-hydroxyaniline (p-aminophenol) in molar ratio (1 : 3) in the presence of 25-mole percent epoxidized natural rubber resulting, PO2APC / ENR-25 and PO4APC / ENR-25, respectively.

The morphology study of PO2APC / ENR-25 showed two separated entities present at the surface of the material, indicating that the entrapment of ENR-25 chains within the tight matrix (1-oxy-2-minophenyl) cyclotriphosphazene (PO2APC) seized to happen.

On the other hand, the morphology of PO4APC / ENR-25 showed a very smooth and homogenous surface texture, indicating the effective entrapment and uniform dispersion of the ENR-25 chains within the loose matrix (1-oxy-4-minophenyl) cyclotriphosphazene (PO4APC).

The DSC analysis of pure PO4APC showed a glass transition temperature (Tg) at 120oC while the neat ENR-25 showed Tg at about -44oC.

The DSC thermogram of PO4APC / ENR-25 reveals a soul glass transition temperature at 76oC which is more than 120oC higher than the Tg of ENR-25 and 44oC lower than the Tg of PO4APC.

The TGA thermogram of neat ENR-25 showed one main decomposition step at 416 C°, while that of PO4APC showed three decomposition steps at 220, 500, 645oC.

The TGA thermogram of PO4APC / ENR-25 showed two decomposition steps, the first occurred at 213°C is attributed to partial decomposition of the cyclomatrix, PO4APC, and the second (main) occurred at 460°C is due to decomposition of ENR-25 trapped in PO4APC.

The structural study of PO4APC / ENR-25 by FT : IR showed all the characteristic absorptions due to PO4APC and ENR-25 without any changes or shifting, indicating that there is no bonds braking or forming taken place between PO4APC and ENR-25.

The 1HNMR analysis of PO4APC / ENR-25 revealed that the relative integral ratio of the epoxy proton at δ 2.70 ppm and olefinic proton at δ 5.17 ppm remains practically similar to that observed in the 1HNMR spectrum of neat ENR-25 which is equal to about 25 %, affirming that the microstructure of ENR-25 remains intact in PO4APC / ENR-25.