High energetic propellants with synergistic mechanical strength are the prerequisites for aerospace industry and missile technology;though glycidyl azide polymer（GAP）is a renowned and a promising energetic polymer which shows poor mechanical and low-temperature properties.HTPB is an inert polymeric binder with unique physico-chemical properties and exhibits low glass transition temperature,hydrolytic stability and high flexibility.In order to obtain high energetic binder system with optimum mechanical properties,an energetic interpenetrating polymer network（EIPN）technique has been opted which may mingle the properties of individuals through networks and interpenetrating polymerization signify an innovative approach to elucidate the problem of polymer incompatibility.In-situ FTIR kinetic studies of GAP and HTPB at various temperatures provide comprehensive information in order to optimize curing conditions for EIPN.The polyurethane reaction has been found to be second order and the rate constant seems to be different between GAP/IPDI and HTPB/IPDI due to reactivity difference of hydroxyl groups.By using Arrhenius and Eyring equations,the activation parameters like enthalpy entropy and activation energy were obtained at different temperatures（60,70,80 and90 0C）.Advanced techniques such as FTIR,FESEM,XPS,TEM,DSC,1H NMR,13C NMR,GPC,Ramen and TGA-DTG have been employed for the characterization.Initially,a novel energetic interpenetrating polymer network（EIPN）of acyl-terminated glycidyl azide polymer（Acyl-GAP）and hydroxyl terminated polybutadiene（HTPB）has effectively synthesized and well characterized via an“in-situ”polymerization by triazole and urethane curing system respectively.Acyl-GAP and dimethyl 2,2-di（prop-2-ynyl）malonate（DDPM）have been synthesized and well characterized by using FTIR,1H NMR,13C NMR and GPC.The maximum tensile strength upto 5.26 MPa and elongation 318%are achieved with HTPB-PU/Acyl-GAP triazole in 50:50 weight ratios.The solvent resistance properties have been investigated by the equilibrium swelling method and the glass transition temperature（Tg）,morphology and thermal stability are evaluated by DSC,SEM and TGA-DTG respectively.Later on,we established a facile sequential polymerization approach inorder to prepare energetic hybrid polymer network（EHPN）through stepwise curation.The detailed curing conditions for the EHPN formation were carried out by using in-situ FTIR kinetic study.Effect of curing ratio（NCO/OH）on mechanical properties of polyurethane networks of GAP and HTPB has been investigated where;hexamethylene diisocyanate biuret trimers（Desmodur N100）and isophorone diisocyanate（IPDI）are used as mixed curative agents.A series of EHPNs have been prepared by varying the relative weight ratios of GAP and HTPB with single poly-isocyanate mixed curing system（IPDI/N100）.A remarkable mechanical strength up to 5.83 MPa and an elongation at break of 359%has been achieved with 50:50 weight ratios of GAP to HTPB with thermally more stable cross-linked network.Thermal properties of as-synthesized PU networks of GAP,HTPB and GAP-HTPB EHPNs with different weight ratios were characterized by DMA and DSC techniques.Thermal degradation behavior and morphological studies were also investigated with TGA-DTG and scanning electron microscopy（SEM）respectively.Afterward we have successfully synthesized and well characterized dipolarophile i.e.bis-propargyl adipate（BPA）and cured GAP through“click chemistry”by the reaction of azido group of GAP with alkynyl group of BPA through 1,3-dipolar cyclo addition reaction to form triazole network.Urethane based GAP networks were also prepared with mixed curing system（IPDI/N100）.With increasing the molar ratio of GAP vs BPA,from 1:1 to1:5,the cross-linking densities of as-prepared materials gradually increased with increasing tensile strength.Triazole based network with 1:3 molar ratio（GAP:BPA）showed maximum mechanical features with 1.92 MPa tensile strength and 79%elongation.The network prepared with dual curing system（the combination of urethane and triazole）showed excellent mechanical properties with 2.65 MPa tensile strength and 114%elongation.Thermal,morphological and sensitivity tests of the triazole,urethane and dual curing based GAP networks were also investigated.Unlike urethane or triazole based GAP networks,dual curing systems is the potential binder for solid composite propellant.In the last,we have developed a novel energetic interpenetrating polymer network（EIPN）nanocomposite comprised of functionalized MWCNTs（f MWCNTs）covalently attached to hydroxyl terminated polybutadiene（HTPB）and glycidyl azide polymer（GAP）by facile in-situ polymerization technique.Three types of fMWCNTs（COOH-fMWCNTs,NCO-fMWCNTs and alkyne-fMWCNTs）were synthesized and well characterized by fourier transform infrared spectroscopy（FTIR）,X-ray photoelectron spectroscopy（XPS）,ramen spectroscopy,transmission electron microscopy（TEM）and thermo gravimetric analysis（TGA）.The effect of fMWCNTs on the mechanical,dispersion and thermal properties of NCO-fMWCNTs/HTPB PU and alkyne-fMWCNTs/Acyl-GAP click was investigated and achieved synergetic properties as compared to neat HTPB and GAP PU networks.Here we develop for the first time EIPN nanocomposite based on NCO-fMWCNTs/HTPB PU and Alkyne-f MWCNTs/Acyl-GAP with different weight ratios and superior tensile strength8.17 MPa with 312%elongation at break was achieved with thermally more stable crosslinked networks.Solid composite propellant based on NCO-fMWCNTs/HTPB PU and Alkyne-f MWCNTs/Acyl-GAP was also prepared and investigated mechanical and thermal properties.An extensive enhancement in thermo-mechanical properties of NCO-fMWCNTs/HTPB PU and Alkyne-fMWCNTs/Acyl-GAP EIPN based nanocomposite have been achieved which may be ascribed to well dispersion of fMWCNTs in the polymer matrix,strong interfacial bonding and entanglements of crosslinked networks during in-situ polymerization.This EIPN based composite propellant with improved mechanical and thermal properties pave the way for its straightforward application as a solid fuel in advanced missile technology.