The Effect of Additives on the Burning Rate of Silicon‐Calcium Sulfate Pyrotechnic Delay Compositions

The effect of fuel particle size as well as the influence of inert and reactive additives on the burning rate of the Si‐CaSO₄ composition was evaluated. The burning rate decreased with increase in fuel particle size, while the enthalpy remained constant. Addition of fuels to the base composition increased the burning rate, with an increase from 12.5 mm ⋅ s⁻¹ to 43 mm ⋅ s⁻¹ being recorded upon 10 wt‐% Al addition. Ternary mixtures of silicon, calcium sulfate, and an additional oxidizer generally decreased the burning rate, with the exception of bismuth trioxide, where it increased. The Si‐CaSO₄ formulation was found to be sensitive to the presence of inert material, addition of as little as 1 wt‐% fumed silica stifled combustion in the aluminum tubes.     

Role of Additives in the Combustion of Ammonium Dinitramide

The thermal decomposition behavior and combustion characteristics of mixtures of ammonium dinitramide (ADN) with additives were studied. Micrometer‐sized particles of Al, Fe₂O₃, TiO₂, NiO, Cu(OH)NO₃, copper, CuO, and nanometer‐sized particles of aluminum (Alex) and CuO (nano‐CuO) were employed. The thermal decomposition was measured by TG‐DTA and DSC. The copper compounds and NiO lowered the onset temperature of ADN decomposition. The heat value of ADN with Alex was larger than that of pure ADN in closed conditions. The burning rates and temperature of the pure ADN and ADN/additives mixtures were measured. CuO and NiO enhance the burning rate, particularly at pressures lower than 1 MPa, because of the catalyzed decomposition in the condensed phase; the other additives lower the burning rate. This negative effect on the burning rate is explained based on the surface temperature measurements by a physicochemical mechanism, which involves a chemical reaction, a phase change of the ammonium nitrate, and the blown‐off droplets of the condensed phase.     

Enhancement of Aluminum Reactivity to Achieve High Burn Rate for an End Burning Rocket Motor

Aluminum is used in solid propellants to increase the specific impulse (I _sp). It is desirable to have high propellant loading in any stage as it reduces the structural coefficient and an end burning grain is known to be the one with the highest propellant loading. As aluminum combustion is a slow process, the time available for aluminum combustion in an end burning configuration will be very small at the start of the combustion process. This demands an increase in the reactivity of the aluminum. This study is built on the fact that mechanical activation of aluminum powder with PTFE (poly‐tetra‐flouro‐ethylene) enhances the reactivity of aluminum powder. This study also deals with the use of this activated aluminum powder in conjunction with various other methods to enhance the burn rates of the solid propellant. The temperature sensitivity was also measured. Based on these results, new designs with end burning grains for the third stage of Polar Satellite Launch Vehicle (PSLV) and for the second and third stage of Pegasus launch vehicle have been proposed to increase the payload capacity. With this new design, it is seen that the payload can be increased by 12.7 % and 17.6 % for PSLV and Pegasus, respectively. The novelty of this design is that with no changes to any other hardware of the above two systems the increase in payload can be achieved.     

High thermal conductive epoxy molding compound with thermal conductive pathway

The epoxy molding compound (EMC) with thermal conductive pathways was developed by structure designing. Three kinds of EMCs with different thermal conductivities were used in this investigation, specifically epoxy filled with Si₃N₄, filled with hybrid Si₃N₄/SiO₂, and filled with SiO₂. Improved thermal conductivity was achieved by constructing thermal conductive pathways using high thermal conductivity EMC (Si₃N₄) in low thermal conductivity EMC (SiO₂). The morphology and microstructure of the top of EMC indicate that continuous network is formed by the filler which anticipates heat conductivity. The highest thermal conductivity of the EMC was 2.5 W/m K, reached when the volume fraction of EMC (Si₃N₄) is 80% (to compare with hybrid Si₃N₄/SiO₂ filled‐EMC, the content of total fillers in the EMC was kept at 60 vol %). For a given volume fraction of EMC (Si₃N₄) in the EMC system, thermal conductivity values increase according to the order EMC (Si₃N₄) particles filled‐EMC, hybrid Si₃N₄/SiO₂ filled‐EMC, and EMC(SiO₂) particles filled‐EMC. The coefficient of thermal expansion (CTE) decreases with increasing Si₃N₄ content in the whole filler. The values of CTE ranged between 23 × 10^?6 and 30 × 10^?6 K^?1. The investigated EMC samples have a flexural strength of about 36–39 MPa. The dielectric constant increases with Si₃N₄ content but generally remains at a low level (<6, at 1 MHz). The average electrical volume resistivity of the EMC samples are higher than 1.4 × 10¹⁰ Ω m, the average electrical surface resistivity of the EMC samples are higher than 6.7 × 10¹⁴ Ω. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Effect of Nano‐Aluminum and Fumed Silica Particles on Deflagration and Detonation of Nitromethane

The heterogeneous interaction between nitromethane (NM), particles of nanoscale aluminum (38 and 80 nm diameter), and fumed silica is examined in terms of the deflagration and detonation characteristics. Burning rates are quantified as functions of pressure using an optical pressure vessel up to 14.2 MPa, while detonation structure is characterized in terms of failure diameter. Nitromethane is gelled using fumed silica (CAB‐O‐SIL^®), as well as by the nanoaluminum particles themselves. Use of nanoaluminum particles with fumed silica slightly increases burning rates compared to the use of larger diameter Al particles; however distinct increases in burning rates are found when CAB‐O‐SIL is removed and replaced with more energetic aluminum nanoparticles, whose high surface area allows them to also act as the gellant. Mixtures including fumed silica yield a reduced burning rate pressure exponent compared to neat NM, while mixtures of aluminum particles alone show a significant increase. Failure diameters of mixture detonations are found to vary significantly as a function of 38 nm aluminum particle loading, reducing more than 50% from that of neat nitromethane with 12.5% (by mass) aluminum loading. Failure diameter results indicate a relative minimum with respect to particle separation (% loading) which is not observed in other heterogeneous mixtures.     

Sb6O13 and Bi2O3 as Oxidants for Si in Pyrotechnic Time Delay Compositions

Lead and its compounds in detonator time delays are being phased out owing to environmental and health concerns. It was found that changing from the conventional rolled lead elements to rigid aluminium tubes caused a significant decrease in the burn rate. It also impaired ignitability, especially of slow burning compositions such as Si BaSO₄. Consequently, potential alternatives for the latter and also the fast burning Si Pb₃O₄ system were sought. Bi₂O₃, prepared by thermal decomposition of bismuth subcarbonate, gave fast burning compositions with silicon as fuel (155 mm s⁻¹ with 20% Si). This system was ignitable by the spit of a shock tube. The Si Sb₆O₁₃ system required an initiating composition and yielded slow burning compositions. The lowest sustainable and reproducible burn rate in lead tubes, in the absence of additives, was 4.8 mm s⁻¹. In lead tubes, it was possible to reduce the burn rate further by adding fumed silica: A composition obtained by adding 10% fumed silica (add‐on basis) to a 10% Si–90% Sb₆O₁₃ composition still burned reliably at a burn rate of 2.3 mm s⁻¹.     

Burning Rates and Thermal Behavior of Bistetrazole Containing Gun Propellants

The influence of two selected bistetrazoles, 5,5′‐bis(1H‐tetrazolyl)‐amine (BTA) and 5,5′‐hydrazinebistetrazole (HBT), on the combustion behavior of a typical triple‐base propellant was investigated. Seven propellant formulations, one reference and six others incorporating 5 %, 15 %, and 25 % of either HBT or BTA compounds, respectively, were mixed and extruded into a cylindrical, no perforations, geometry. The resulting propellants showed high burning rates, up to 93 % higher than the reference formulation at 100 MPa. However, the increase in burning rates came at the cost of higher burning rate dependency on pressure, with a pressure exponent as high as 1.4 for certain formulations. HBT‐containing propellants showed notably lower flame temperature when compared to the reference formulation, with a flame temperature reduction of up to 461 K for the propellant containing 25 % HBT. The thermal behavior of the propellants was also investigated through DSC experiments. The addition of bistetrazoles provided lower decomposition temperatures than the pure nitrogen‐rich materials, indicating that the two compounds probably react readily with the −ONO₂ groups present in the nitrocellulose and the plasticizers used in the formulation. The onset temperature of all propellants remained within acceptable ranges despite the observed decrease caused by the addition of the bistetrazole compounds.     

Tribological behavior of micrometer‐ and nanometer‐Al2O3‐particle‐filled poly(phthalazine ether sulfone ketone) copolymer composites used as frictional materials

Micrometer‐ and nanometer‐Al₂O₃‐particle‐filled poly(phthalazine ether sulfone ketone) (PPESK) composites with filler volume fractions ranging from 1 to 12.5 vol % were prepared by hot compression molding. We evaluated the tribological behaviors of the PPESK composites with the block‐on‐ring test rig by sliding PPESK‐based composite blocks against a mild carbon steel ring under dry‐friction conditions. The effects of different temperatures on the wear rate of the PPESK composites were also investigated with a ball‐on‐disc test rig. The wear debris and the worn surfaces of the PPESK composites were investigated with scanning electron microscopy, and the structures of the PPESK composites were analyzed with IR spectra. The lowest wear rate, 7.31 × 10^?6 mm³ N^?1 m^?1, was obtained for the composite filled with 1 vol %‐nanometer Al₂O₃ particles. The composite with nanometer particles exhibited a higher friction coefficient (0.58–0.64) than unfilled PPESK (0.55). The wear rate of 1 vol %‐nanometer‐Al₂O₃‐particle‐filled PPESK was stable and was lower than that of unfilled PPESK from the ambient temperature to 270°C. We anticipate that 1 vol %‐nanometer‐Al₂O₃‐particle‐filled PPESK can be used as a good frictional material. We also found that micrometer‐Al₂O₃‐particle‐filled PPESK had a lower friction coefficient at a filler volume fraction below 5%. The filling of micrometer Al₂O₃ particles greatly increased the wear resistance of PPESK under filler volume fractions from 1 to 12.5%. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 95: 993–1001, 2005     

Combustion Measurements of Fuel‐Rich Aluminum and Molybdenum Oxide Nano‐Composite Mixtures

Fuel rich nano‐composite powders of aluminum and molybdenum oxide were tested for ignition and combustion behind the incident and reflected shock waves in a shock tube. The powders consisted of approximately 10 μm particles, each of which contained Al and MoO₃ mixed by mechanical alloying on the nano‐scale. These powders were aluminum rich with composition ratios of 4 : 1, 8 : 1, and 16 : 1 Al : MoO₃ by mass. Ignition tests were performed behind incident shocks for temperatures in the range of 900 to 1500 K. From these tests, ignition delay times were obtained, and some information on combustion duration was also derived. Samples were tested in air at 0.2 MPa, and compared against nano‐Al, 2.7 μm Al, and 10 μm Al baselines. Ignition results for the baseline Al cases were as expected: 10 μm Al not igniting until 2000 K, 2 μm Al igniting down to ∼1400 K, and n‐Al igniting as low as 1150 K. The thermite samples showed considerable improvement in ignition characteristics. At the lowest temperature tested (900 K), both the 8 : 1 and 4 : 1 samples ignited within 250 μs. The 16 : 1 sample (94% Al) ignited down to 1050 K – which represents an improvement of roughly 1000 K over baseline Al with only a small energetic penalty. In all cases, the ignition delay increased as the amount of MoO₃ in the composite was reduced. The 4 : 1 nano‐composite material ignited as fast or faster than the n‐Al samples. Ignition delay increased with decreasing temperature, as expected. Emission spectra and temperature data were also taken for all samples using high‐speed pyrometry and time‐integrated spectroscopy. In these cases, measurements were made behind the reflected shock using end‐wall loading, though the conditions (temperature, pressure, and gas composition) were identical to the incident shock tests. Spectroscopy showed strong AlO features in all the samples, and the spectra fit well to an equilibrium temperature. Broadband, low resolution spectra were also fit to continuum, gray body temperatures. In general, the observed temperatures were reasonably close to 3500 K, which is similar to the combustion temperatures of pure aluminum under these conditions.     

Spectroscopic,thermal, and electrical investigations of PVDF films filled with BiCl3

Poly(vinylidene fluoride) (PVDF) films filled with BiCl₃ in the mass fraction range of 0.1 ≤ W ≤ 10 were prepared. α‐ and β‐Crystalline PVDF phases were detected and characterized by spectroscopic analysis. Fourier transform infrared analysis detected the presence of α‐ and β‐phase head‐to‐head and tail‐to‐tail polymer chain defects. The band detected at 1670 cm^?1 was assigned to C?C, indicating polarons in the polymeric matrix. The degree of crystallinity increased by increasing the filling level (FL), and the maximum relative β‐phase content was found at w = 5% FL. This result was confirmed by X‐ray diffraction (XRD) and differential scanning calorimetry (DSC) analysis. The X‐ray analysis confirmed the presence of α and β phases, and no peaks corresponding to pure BiCl₃ were found. DSC therograms showed a sharp endothermic peak at T₁ = 444 K for different FLs because of the melting. This peak was used to calculate the activation energy and the order of the reaction. The DC electrical resistivity was attributed to the one‐dimensional interpolaron hopping mechanism. The FL dependence of log ρ and hopping distance (R_o) at 373 K was observed, indicating the FL affected the distribution of the hopping sites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2125–2131, 2006     

Combustion Effects of Nitrofulleropyrrolidine on RDX‐CMDB Propellants

The effect of N‐methyl‐2‐(3‐nitrophenyl)pyrrolidino[3′,4′:1,2]fullerene (mNPF) on the decomposition characteristics of hexogen (RDX) was investigated using differential scanning calorimetry (DSC). The results show that mNPF can accelerate the decomposition of RDX, the peak temperature (T_p) of the exothermal decomposition is reduced by 6.4 K, and the corresponding apparent activation energy (E_a) is decreased by 8.7 kJ mol⁻¹. N‐methyl‐2‐(3‐nitrophenyl)pyrrolidino[3′,4′:1,2]fullerene (mNPF), carbon black (CB), and C₆₀ were used as combustion catalysts to improve the combustion performance of a composite modified double‐base propellant containing RDX (RDX‐CMDB). The burning rate experimental results show that mNPF has a stronger catalytic effect than C₆₀ and CB. The magnitude of the effect of the three carbon substances on the enhancement of the burning rate is as follows: mNPF>C₆₀>CB. The catalytic effects of different contents of mNPF on the burning rates of RDX‐CMDB propellants were also studied, and the results show that the burning rates of RDX‐CMDB propellants are improved with increasing mNPF content. The plateau burning rate of a RDX‐CMDB propellant can be increased to 19.6 mm s⁻¹ when 1.0 % mNPF is added, and the corresponding plateau combustion region occurs at 8–22 MPa.     

Manganese as Fuel in Slow‐Burning Pyrotechnic Time Delay Compositions

Manganese metal was evaluated as a fuel for slow‐burning delay compositions press‐filled in aluminium or compaction‐rolled in lead tubes. Oxides of antimony, bismuth, copper, manganese and vanadium were considered as oxidants. Measured burn rates for binary mixtures varied between 5 and 22 mm s⁻¹ but slower burning ternary and quaternary compositions were also found. The addition of fumed silica to the Mn/MnO₂ system had little effect on the propagation rate but a low level addition of hollow glass sphere significantly reduced the burn rate. Mn MnO₂ mixtures showed reliable burning over a wide stoichiometric range. In this system the fuel and the oxidant share a common metal. They combine to form the more stable intermediate oxide (MnO) releasing considerable quantities of heat in the process.     

Dielectric Properties of Pure and Gd‐Doped HfO2 Ceramics

The pure, 2 at.%, and 20 at.% Gd‐doped HfO₂ ceramics were prepared by the standard solid‐state reaction technique. Dielectric properties of these ceramics were investigated in the temperature range 300–1050 K and frequency range 20–5 × 10⁶ Hz. Our results revealed an intrinsic dielectric constant around 20 in the temperature below 450 K for all tested ceramics. Two oxygen‐vacancy‐related relaxations R1 and R2 were observed at temperatures higher than 450 K, which were identified to be a dipolar relaxation due to grain response and a Maxwell–Wagner relaxation due to grain‐boundary response, respectively. The dielectric properties of the pure and slightly doped (2 at.%,) samples are dominated by the grain‐boundary response, which results in a colossal dielectric behavior similar to that found in CaCu₃Ti₄O₁₂. The doping level of 20 at.% leads to the structural transformation from monoclinic phase to cubic phase. The dielectric properties of the heavily doped HfO₂ are dominated by the grain response without any colossal dielectric behavior.     

Epoxy resin/phosphorus‐based microcapsules: Their synergistic effect on flame retardation properties of high‐density polyethylene/graphene nanoplatelets composites

Two types of microcapsule flame retardants are prepared by coating ammonium polyphosphate (APP) and aluminum diethylphosphinate (ADP) with epoxy resin (EP) as the shell via in situ polymerization, and blended with high density polyethylene (HDPE)/graphene nanoplatelets (GNPs) composites to obtain flame‐retardant HDPE materials. Fourier transform infrared spectroscopy, scanning electron microscopy (SEM), and water contact angle results confirm the formation of core–shell structures of EP@APP and EP@ADP. The limiting oxygen index (LOI), vertical burning test (UL‐94), cone calorimetry, and Raman spectroscopy are employed to characterize the HDPE/GNPs composites filled with EP@APP and EP@ADP core–shell materials. A UL94 V‐0 level and LOI of 34% is achieved, and the two flame retardants incorporated in the HDPE/GNPs composite at 20 wt % in total play a synergistic effect in the flame retardancy of the composite at a mass ratio of EP@ADP:EP@APP = 2:1. According to the cone‐calorimetric data, the compounding composites present much lower peak heat release rate (300 kW/m²) and total heat release (99.4 MJ/m²) than those of pure HDPE. Raman spectroscopic analysis of the composites after combustion reveals that the degree of graphitization of the residual char can reach 2.31, indicating the remarkable flame retarding property of the composites. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46662.     

Iron Nanoparticle Additives as Burning Rate Enhancers in AP/HTPB Composite Propellants

Burning rate measurements were carried out for ammonium perchlorate/hydroxyl‐terminated polybutadiene (AP/HTPB) composite propellants with iron (Fe) nanoparticles as additives. Experiments were performed in a strand burner at pressures from 0.2 to 10 MPa for propellants containing approximately 80 % AP and Fe nanoparticles (60–80 nm) at concentration from 0 to 3 % by weight. It was found that the addition of 1 % Fe nanoparticles increased burning rate by factors of 1.2–1.6. Because Fe nanoparticles are oxidized on the surface and have high surface‐to‐volume ratio, they provide a large surface area of Fe₂O₃ for AP thermal decomposition catalysis at the burning propellant surface, while also providing added energy release due to the oxidation of nanoparticle sub‐shell Fe. The increase in burning rate due to Fe nanoparticle content is similar to the increase in burning rate caused by the addition of iron oxide (Fe₂O₃) particles observed in prior literature.     

Enhanced Luminescence in the SrMgAl10O17: Eu2+ Blue Phosphor Prepared by a Hybrid Urea‐Sol Combustion Route

A phase‐pure and high‐brightness blue phosphor, Eu²⁺ doped SrMgAl₁₀O₁₇ (SAM), was synthesized through a hybrid urea‐sol combustion route. The structure, photoluminescence spectra, and thermal stability of the SAM were investigated in this work. The phosphor had a homogeneous and rod‐like microstructure, showing a broad emission band centered at 465 nm under the 330 nm excitation. The concentration for luminescence quenching of SAM: Eu²⁺ occurred at 10 mol%, which doubled that of the phosphor prepared by the conventional combustion method. Compared with the traditional combustion method, the hybrid route led to improvements in luminescence by 52.2%, external quantum efficiency by 16.2%, and thermal stability by 8.8% at 435 K. The blue phosphor prepared by the new method could thus be potentially used with near ultraviolet light‐emitting diodes.     

The effect of Fe2+ state in electrical property variations of Sn‐doped hematite powders

The structural, electrical, and chemical properties of Sn‐doped Fe₂O₃ powders were investigated. Various quantities of Sn‐doped Fe₂O₃ powders were synthesized using solid‐state reactions. Rietveld analysis for the powders that were doped below 2% revealed a phase‐pure Sn‐doped Fe₂O₃ structure (i.e., identical to Fe₂O₃ structure). Alternatively, the analysis for the powders that were doped more than 3% exhibited secondary phase. The unit cell volume and electrical conductivity of the phase‐pure samples increased with an increase in the doping concentration. X‐ray photoelectron spectroscopy measurements showed an increased Fe²⁺ state with the increase in Sn doping concentration. Therefore, the improved electrical conductivity and unit cell volume with the increase in doping concentration of the phase‐pure powders might be related to the increased Fe²⁺ state.     

Calcium Sulfate as a Possible Oxidant in “Green” Silicon‐based Pyrotechnic Time Delay Compositions

Chemical time delay detonators are used to control blasting operations in mines and quarries. Slow burning Si BaSO₄ pyrotechnic delay compositions are employed for long time delays. However, soluble barium compounds may pose environmental and health risks. Hence inexpensive anhydrous calcium sulfate was investigated as an alternative “green” oxidant. EKVI simulations indicated that stoichiometry corresponds to a composition that contains less than 30 wt‐% Si. However combustion was only supported in the range of 30–70 wt‐% Si. In this range the bomb calorimeter data and burn tests indicate that the reaction rate and energy output decrease with increasing silicon content. The measured burning rates in rigid aluminum elements ranged from 6.9 to 12.5 mm s⁻¹. The reaction product was a complex mixture that contained crystalline phases in addition to an amorphous calcium containing silicate phase. A reaction mechanism consistent with these observations is proposed.     

Thermal and electrical properties of aluminum nitride/boron nitride filled polyamide 6 hybrid polymer composites

The effects of boron nitride (BN) and aluminum nitride fillers on polyamide 6 (PA6) hybrid polymer composites were investigated. In particular, the thermal and electrical conductivity, thermal transition, thermal degradation, mechanical and morphological properties and chemical bonds characteristic of the materials with crystal structure of BN and aluminum nitride (AlN) filled PA6 prepared at different concentrations were characterized. Thermal conductivity of hybrid systems revealed a 1.6-fold gain compared to neat PA6. The highest thermal conductivity value was obtained for the composite containing 50 vol% additives (1.040 W/m K). A slight improvement in electrical conductive properties of composites appears and the highest value was obtained for the 50 vol% filled composite with only an increase by 3%. The microstructure of these composites revealed a homogeneous dispersion of AlN and BN additives in PA6 matrix. For all composites, one visible melting peak around 220°C related to the α-form crystals of PA6 was detected in correlation with the X-ray diffraction results. An improved thermal stability was obtained for 10 vol% AlN/BN filled PA6 composite (from 405.41°C to 409.68°C). The tensile strength results of all composites were found to be approximately 22% lower than pure PA6.     

Cationic UV curing behavior and thermal properties of oxetane‐modified polysiloxane prepared from tetraethyl orthosilicate

The oxetane‐modified polysiloxane (Oxe‐PSiO) was synthesized via the partial hydrolysis/condensation of tetraethyl orthosilicate (TEOS) and then transesterification reaction with 3‐ethyl‐3‐(hydroxymethyl)oxetane (EHO), and characterized by FT‐IR, ¹H NMR, ¹³C NMR, and ²⁹Si NMR spectroscopy. Using the water/TEOS molar ratios of 0.8–1.2, the number‐average molecular weights and polydispersity indices were obtained by GPC to range from 1.013 to 2.716 g mol^?1 and around 2.0, respectively. The viscosity of Oxe‐PSiO prepared from the water/TEOS molar ratio of 1.2 sharply increased to 177,545 cps from 438 cps of that from the molar ratio of 0.8. A series of cationic UV‐curable formulations were prepared by blending the Oxe‐PSiO synthesized with the water/TEOS molar ratio of 1.0 into an commercial oxetane‐based resin, 3,3′‐[oxydi(methylene)]bis(3‐ethyloxetane), in different weight ratios. The photopolymerization kinetics studied by photo‐DSC in the presence of triphenylsulphonium hexafluoroantimonate as a cationic photoinitiator showed that both the maximum photopolymerization rate and final oxetane conversion in the cured film decreased with increasing Oxe‐PSiO loading mainly due to the sharp increase in viscosity. The DMTA and DSC results both indicated the improvement in thermal stability, showing 12 and 13.4°C, respectively, higher T_g for the cured film with 50 wt % Oxe‐PSiO loading compared with the pure polymer. Moreover, the temperatures (T_10% and T_50%) at the weight loss of 10 and 50% and final char yields measured by TGA increased with increasing Oxe‐PSiO content. After adding 50 wt % Oxe‐PSiO, compared with the pure polymer the T_10% increased from 349 to 361°C, while the T_50% increased from 409 to 424°C, and with a char yield increase of 8.2% at 800°C. In addition, its greatly increased crosslinking density due to the formation of silica network resulted in the enhancement in pencil hardness from B of the pure polymer to 2H grade. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011