Low-temperature Decomposition Research Articles

Growth of hafnium dioxide thin films via metal-organic chemical vapor deposition

Metal-organic chemical vapour deposition (MOCVD) is a key technique for depositing thin solid film materials for use in important technological applications. To obtain thin films of the desired standard, it is essential to design volatile, reactive and thermally stable precursors. A metal-organic precursor consisting of Hf with excellent vaporization characteristics and low decomposition temperature has been reported. Hafnium dioxide thin films on a Mo substrate were obtained via thermal MOCVD using Hafnium(IV) acetylacetonate(Hf(acac)4) in a horizontal cold-wall reactor. The Hf(acac)4 precursor was synthesized from HfCl4 and Hthd in methanol. Hf(acac)4 was characterized using elemental analysis and infrared spectroscopy. The thermal decomposition properties were studied using thermogravimetric analysis under a nitrogen atmosphere. The results showed that Hf(acac)4 was completely volatised at 245 °C. The thin films products were investigated using x-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The results from these measurements revealed that the main crystalline phase was the monoclinic phase, the surface consists of hafnium and oxygen and the morphology was densely packed and composed of visible grains.

Novel energetic coordination compound [Cu(AT)4]Cl2 for catalytic thermal decomposition of ammonium perchlorate

The lower high-temperature decomposition (HTD) temperature of ammonium perchlorate (AP) and more heat release of composite solid propellants (CSPs) put forward higher requirements on thermal catalysts. Herein, a new anhydrous energetic coordination compound [Cu(AT)4]Cl2 was well-designed and synthesized by coordination reaction of copper(II) and 5-amino-1H-tetrazole (AT), in which copper(II) catalytic active center has catalytic effect on reducing the HTD temperature of AP, and energetic AT can increase heat release. The structure of [Cu(AT)4]Cl2 was well determined by single crystal X-ray diffraction. The excellent thermal stability of [Cu(AT)4]Cl2 was verified by the results of thermogravimetric analysis and non-isothermal kinetics method. The catalytic activity of [Cu(AT)4]Cl2 for AP thermal decomposition was studied by the differential thermal analytical. The results indicated that the HTD peak of AP was significantly decreased by 60 ​K–495 ​K, and the activation energy of AP decreased by 57.5 ​kJ ​mol−1 to 163.37 ​kJ ​mol−1. The results of TGA-FTIR shows that the [Cu(AT)4]Cl2 will decompose and produce HCN gas before catalyzing AP, then the thermal decomposition products participated in the thermal decomposition of AP as an effective component of catalysis. The mechanical sensitivities and energetic characteristics of [Cu(AT)4]Cl2 was also studied by mechanical sensitometer, Calvet-type differential thermal conductivity calorimeter, and Kamlet-Jacbos equations. The results indicated that [Cu(AT)4]Cl2 has lower sensitivity than Trinitrotoluene and brilliant energetic characteristics. The [Cu(AT)4]Cl2 is expected to be one candidate additive in CSPs for catalytic thermal decomposition of AP.

Zeolite Imidazolate Frameworks-67 Precursor to Fabricate a Highly Active Cobalt-Embedded N-Doped Porous Graphitized Carbon Catalyst for the Thermal Decomposition of Ammonium Perchlorate.

The more apparent specific heat release at a lower high-temperature decomposition (HTD) temperature of ammonium perchlorate (AP) poses a challenge for the development of highly active catalysts. In this work, a well-designed cobalt-embedded N-doped porous graphitized carbon (Co@NC) catalyst is obtained by high-temperature calcination of a zeolite imidazolate frameworks-67 precursor, in which the cobalt catalytic active center realizes effective nanoscale dispersion; meanwhile, the cobalt and N-doped porous graphitized carbon can release considerable heat after oxidation, and the cobalt oxides have an excellent catalytic effect on reducing the HTD temperature of AP. The catalytic activity of Co@NC was tested by a differential thermal analytical method. The results indicated that the HTD peak of AP was significantly decreased by 100.5 °C, the apparent activation energy of the HTD reaction of AP was reduced by 82.0 kJ mol–1, and the heat release compared with pure AP increased 2.9 times. On teh basis of these findings, Co@NC is expected to be one of the best candidate materials for AP thermal decomposition.

Cold Sintering of PZT 2-2 Composites for High Frequency Ultrasound Transducer Arrays

Medical ultrasound and other devices that require transducer arrays are difficult to manufacture, particularly for high frequency devices (>30 MHz). To enable focusing and beam steering, it is necessary to reduce the center-to-center element spacing to half of the acoustic wavelength. Conventional methodologies prevent co-sintering ceramic–polymer composites due to the low decomposition temperatures of the polymer. Moreover, for ultrasound transducer arrays exceeding 30 MHz, methods such as dice-and-fill cannot provide the dimensional tolerances required. Other techniques in which the ceramic is formed in the green state often fail to retain the required dimensions without distortion on firing the ceramic. This paper explores the use of the cold sintering process to produce dense lead zirconate titanate (PZT) ceramics for application in high frequency transducer arrays. PZT–polymer 2-2 composites were fabricated by cold sintering tape cast PZT with Pb nitrate as a sintering aid and ZnO as the sacrificial layer. PZT beams of 35 μm width with ~5.4 μm kerfs were produced by this technique. The ZnO sacrificial layer was also found to serve as a liquid phase sintering aid that led to grain growth in adjacent PZT. This composite produced resonance frequencies of >17 MHz.

Comparing the effects of different metal oxides on low temperature decomposition of PVC

Polyvinyl chloride (PVC) is one of the most widely used plastics in the world. When PVC is heated, HCl will form, causing equipment corrosion, product quality decline, environmental pollution and other problems. Therefore, more attention is paid to recycling of PVC than other plastics. In this study, the reaction mechanisms of PVC with different metal oxides (MOx: CaO, ZnO, CuO, MgO, Fe2O3, Al2O3) at low temperature (310 °C) were compared, with focus on chlorine capture and dehydrochlorination product (De-Cl PVC) property. The results showed that when the radius of metal ion was smaller, the extrapolated onset temperature (Ti) of PVC-MOx pyrolysis tended to be lower, such as PVC-ZnO, PVC-CuO and PVC-Al2O3. Direct reaction of PVC and MOx was deduced for PVC-CuO and PVC-ZnO pyrolysis, based on the lower Ti and peak temperature (Tmax) than that of PVC pyrolysis. MOx that did not significantly lower Tmax was supposed to react with HCl that dissociated from PVC. The addition of ZnO significantly reduced the release of HCl (0.5%) and captured 97.6% of chlorine as inorganic chloride salts. However, the chloride salts produced from PVC-MgO pyrolysis could decompose at low temperature, thus releasing HCl again, and the C atoms in PVC-CuO system could react with copper chloride salts and H2O, to form and release HCl. The capture effects of chlorine by Fe2O3 and Al2O3 were not good. With addition of MOx, all De-Cl PVCs were rich in C=C-H and (C)3C-H structures. Fe2O3, MgO and CuO reduced the release of volatile hydrocarbons, while CaO, ZnO and Al2O3 increased the release of volatile hydrocarbons. Except for CaO and CuO, the other MOx increased the amount of residual hydrocarbon (De-Cl PVC).

Neutron Diffraction Study of Kinetics of Low Temperature Decomposition of Martensite in Medium Carbon Steel

Neutron Diffraction Study of Kinetics of Low Temperature Decomposition of Martensite in Medium Carbon Steel

Design of three dimensional flower-like MXene/manganese-cobalt spinel nanocomposites for efficient catalytic thermal decomposition of ammonium perchlorate

A series of MXene/MnCo2O4.5 nanocomposites was successfully prepared by hydrothermal, ice crystal template and physical blend methods, respectively. Various characterizations indicated that hydrothermal method could successfully loaded MnCo2O4.5 nanoparticles on the surface of MXene nanosheets to obtain MMC-W nanocomposites with 3D flower-like structure, which could give MMC-W large specific surface area. The HTD temperature and decomposition heat of AP with adding 2.0 wt% MMC-W could significantly decrease to 304.7 °C and increase to 1310.9 J g-1, respectively. The lowest decomposition temperature (286.1 °C) and the highest heat release (1427.6 J g-1) of AP could be obtained by adding 8.0 wt% and 4.0 wt% of MMC-W, respectively. Moreover, MMC-W (2.0 wt%) could also significantly reduce the Ea of pure AP by 118.3 kJ mol-1 and increase the k value for AP by 11.2 times. The excellent catalytic performance of MMC-W was owing to the synergistic effect of nano-sized MnCo2O4.5 and MXene nanosheets. Owing to its high catalytic activity, MMC-W would be used as an excellent catalyst for ameliorating AP decomposition and supply an idea for the preparation of novel metal oxide nanoparticles.

Design and Catalytic Behaviour of Hosted in Activated Carbon Foam CoxZn1−xFe2O4 Ferrites

Carbon foams with different surface functionality and tailored texture characteristics were prepared from mixtures containing coal tar pitch and furfural in different proportions. The obtained materials were used as a host matrix for the preparation of zinc- and cobalt-mixed ferrite nanoparticles. The texture, morphology, phase composition, and the related redox and catalytic properties of the obtained composites were characterized by low-temperature nitrogen physisorption, XRD, SEM, HRTEM, FTIR, Mössbauer spectroscopy, TPR and catalytic decomposition of methanol to syngas. The impact of the carbon support on the formation of Co- and Zn-mixed ferrites was discussed in detail using KIT-6 silica-based modifications as reference samples. The catalytic behavior of the ferrites was considered in a complex relation to their composition, morphology, location in the porous matrix and metal ions distribution in the spinel sub-lattices. The higher amount of furfural in the carbon foam precursor promoted the formation of cobalt-rich, more accessible and highly active methanol decomposition to syngas spinel particles.

Modification of Branched Polyethyleneimine Using Mesquite Gum for Its Improved Hemocompatibility.

In the present study, the modification of branched polyethyleneimine (b-PEI) was carried out using mesquite gum (MG) to improve its hemocompatibility to be used in biomedical applications. In the copolymer synthesis process (carboxymethylated mesquite gum grafted polyethyleneimine copolymer (CBX-MG-PEI), an MG carboxymethylation reaction was initially carried out (carboxymethylated mesquite gum (CBX-MG). Subsequently, the functionalization between CBX-MG and b-PEI was carried out using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS) as crosslinking agents. The synthesis products were characterized using Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and thermogravimetric analysis (TGA). Thermogravimetric analysis showed that CBX-MG and CBX-MG-PEI presented a lower decomposition temperature than MG. The CBX-MG-PEI has a high buffer capacity in the pH range of 4 to 7, similar to the b-PEI. In addition, the CBX-MG-PEI showed an improvement in hemocompatibility in comparison with the b-PEI. The results showed a non-hemolytic property at doses lower than 0.1 µg/mL (CBX-MG-PEI). These results allow us to propose that this copolymer be used in transfection, polymeric nanoparticles, and biomaterials due to its physicochemical and hemocompatibility properties.

Bulk defect-dependent initial steps of acetone oxidation on rutile TiO2(110)

Systematic model investigations revealed that defects, particularly bulk Ti3+ interstitials, play a crucial role in directing reactions of alcohols and aldehydes at rutile Titania (TiO2), a cheap, nontoxic and earth abundant catalyst. Coadsorption with oxygen may enhance the population of certain reaction paths. As systematic studies on the reactivity of ketones are rare, we studied the interaction of acetone with slightly (∼5%) and highly (∼20%) reduced rutile TiO2(110) surfaces by Temperature Programmed Desorption (TPD) and polarised Fourier-Transform Infrared Reflexion Absorption Spectroscopy (FT-IRRAS) to elucidate surface intermediates and reaction products. For low defect densities the only reaction observed occurs at high temperatures resulting in the formation of propane and propene of less than 1%. At high Ti3+ defect densities a stabilisation of acetone on the surface by the formation of a diolate was observed. In the presence of oxygen, the partial formation of a tilted acetone species is apparent in FT-IRRAS. A concomitant activation of the CH-bond can be attributed to the interaction with Oad atoms and can relate to thermally induced low temperature decomposition to water and carbon dioxide. However, in contrast to alcohols and aldehydes, both intermediates do not react to other more valuable products.

Cinnamaldehyde adsorption and thermal decomposition on copper surfaces

The uptake and thermal chemistry of cinnamaldehyde on Cu(110) single-crystal surfaces were characterized by temperature-programmed desorption and x-ray photoelectron spectroscopy (XPS). Adsorption at 85 K appears to be initiated by low-temperature decomposition to form styrene, which desorbs at 190 K, followed by the sequential buildup of a molecular monolayer and then a condensed molecular film. Molecular desorption from the monolayer occurs at 410 K, corresponding to a desorption energy of approximately 98 kJ/mol, and further decomposition to produce styrene (again) and other fragmentation products is seen at 550 K. The molecular nature and the quantitation of the low-temperature uptake were corroborated by the XPS data, which also provided hints about the adsorption geometry adopted by the unsaturated aldehyde on the surface. Density functional theory calculations, used to estimate adsorption energies as a function of coverage and coordination mode, pointed to possible η1-O binding, at least at high coverages, and to a stabilizing effect on the surface by the aromatic ring of cinnamaldehyde. Finally, coadsorption of oxygen on the surface was found to weaken the binding of cinnamaldehyde to the Cu substrate at high coverages without enhancing its uptake, but to not modify the decomposition mechanism or energetics in any significant way.

Composition of solid and gaseous primary combustion products of boron-based fuel-rich propellant

The investigation of the primary combustion products of boron-based fuel-rich propellants is conducive to understanding the mechanism of the two-stage combustion process and provides important information for the prediction and organization of secondary combustion processes. The present investigation methods include numerical simulation and experimental analysis. The former deviates considerably from the actual conditions. The latter is currently a reliable and practical method, although it is difficult to quantify when the components are complex. In this work, SEM, LPSA, XRD, XPS, IC, ICP–MS, AAS, EDS, and chemical analysis methods were employed to qualitatively and quantitatively analyze the 3 solid products (aggregations, condensed-phase products, and flocculent products) at 1, 5, and 10 bar. GC, GC–MS, and IC combined with chemical tests were adopted to investigate the gaseous products (including chlorine-containing gas) for the first time. The solid products primarily included B2O3, B(HO)3, unburned boron, KB5O8(H2O)4, KCl, C, NH4Cl, NH4Mg(H2O)6Cl3, B13C2, Fe3O4, Mo, MgO, Mg(OH)2, MoO3, C3N4, BN, MgCO3(H2O)3 (or MgCO3), MoO2, Fe4(Fe(CN)6)3, and FeB (or BFe4), and the first 7 were dominant. The reaction degree of boron was less than 50 wt% (increasing with increasing pressure), indicating the significance of the secondary combustion process. The reacted boron was likely to react with O and C but not with N. The generated B2O3 vapor easily combined with H2O to form B(HO)3 or reacted with KCl (from the thermal decomposition of KP) and H2O to produce KB5O8(H2O)4 after cooling. There was less B13C2 (its content increased with increasing pressure, resulting in increases in particle size), since it was easily oxidized to generate B2O3. NH4Cl was produced by the oxidation-reduction reaction between the NH3 and HClO4 released from large-sized AP, and some of it crystallized with MgCl2 and H2O to form NH4Mg(H2O)6Cl3. The gaseous products primarily included N2, H2, CO, CH4, CO2, C2H4, C2H2, HCl, C4H6, C3H6, Cl2, C6H6, and other hydrocarbons. N2 and H2 had the highest content. The N2 content increased with increasing pressure, while the content of the combustible gases decreased, indicating that high pressure promotes the propellant reaction. The results also show that high pressure was conducive to the low-temperature decomposition of AP (producing more HCl and Cl2) and the reaction of boron and hydrocarbons (generating more B13C2), while it had an adverse effect on the C reaction (producing less COx and mostly CO). Nevertheless, the increasing pressure had little effect on the combustion product components but did affect the content within the pressure range.

Oxidative depolymerization of lignin using nitric acid under ambient conditions

In this work, we demonstrated an innovative and cost-effective strategy to produce high- value depolymerized kraft lignin (DKL) from softwood kraft lignin (SKL) and hardwood kraft lignin (HKL). The depolymerization of kraft lignin was successfully achieved by an oxidative approach using nitric acid under ambient conditions (room temperature and pressure). This novel approach has the following features: ambient process conditions, no heat required, absence of catalysts or organic solvents, and no further purification process being required. The obtained DKL products were characterized extensively by gel permeation chromatography with ultraviolet detector (GPC-UV), Fourier transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), pyrolysis–gas chromatography–mass spectrometry (Py-GC/MS), potentiometric titration and elemental analysis. Treatment of SKL or HKL at a KL/nitric acid (HNO3) mass ratio of 1:4 (w/w) at room temperature for 84 h resulted in DKL products with a weight-average molecular weight (Mw) of 1350 Da, much lower than that of the original lignins. In addition, the DKL products displayed a significant increase in carboxylic acid group content, a high solubility in water at low pH and, significantly lower decomposition temperatures compared to the original lignins. It was confirmed that nitration of the lignin structure occurred during nitric acid-oxidative depolymerization, as evidenced by the presence of 5% nitrogen (N) content in the DKL products.

Coinage Metal Complexes with Di-tertiary-butyl Sulfide as Precursors with Ultra-Low Decomposition Temperature.

We report here the synthesis of [Cu2 (TFA)4 (t Bu2 S)2 ] (1), [Ag4 (TFA)4 (t Bu2 S)4 ] (2) and [AuCl(t Bu2 S)] (3) (TFA=trifluoroacetate), which decompose in solution medium at ultra-low temperature (e. g., in boiling toluene) to afford phase-pure and highly crystalline Cu9 S5 , Ag2 S and metallic Au nanoparticles, respectively. The low decomposition temperature of these precursors is attributed to the facile decomposition mechanism in the di-tertiary-butyl sulfide ligand. These results are a significant step in the direction of establishing a general low-temperature strategy spanning a range of systems including thermodynamically metastable materials and incorporate them in technologies that are sensitive to the harsh conditions.

Recent progress in the development of high-performance bonded magnets using rare earth–Fe compounds

Permanent magnets, and particularly rare earth magnets such as Nd-Fe-B, have attracted much attention because of their magnetic properties. There are two well-established techniques for obtaining sintered magnets and bonded Nd-Fe-B magnets. Powder metallurgy is used to obtain high-performance anisotropic sintered magnets. To produce bonded magnets, either melt-spinning or the hydrogenation, disproportionation, desorption, and recombination process is used to produce magnet powders, which are then mixed with binders. Since the development of Nd-Fe-B magnets, several kinds of intermetallic compounds have been reported, such as Sm2Fe17Nx and Sm(Fe,M)12 (M: Ti, V, etc.). However, it is difficult to apply a liquid-phase sintering process similar to the one used for Nd-Fe-B sintered magnets in order to produce high-performance Sm-Fe–based sintered magnets because of the low decomposition temperature of the compound and the lack of a liquid grain boundary phase like that in the Nd-Fe-B system. Therefore, bonded magnets are useful in the production of bulk magnets using these Sm-Fe based compounds. This article reviews recent progress in our work on the development of high-performance bonded magnets using Nd2Fe14B and Sm2Fe17Nx compounds.

Low Fluorine Colorless Polyimide Substrate for Flexible OLED Display

Flexible display has become the main stream for the next innovative display. To build the flexible electronics, polyimide varnish is usually coated on the carrier glass with the thickness of a few micrometer and various devices such as flexible solar cell, flexible display, flexible printed circuit board, flexible terahertz sensor, and smart window [1]. Currently available colorless polyimide varnish is usually made of fluorine contained 6-FDA, which has good characteristics such as high transmittance, low yellow index, excellent solubility, but also has bad characteristics such as low decomposition temperature, high coefficient of thermal expansion, high cost, and environmentally unfriendliness due to fluorine. In this study, we make low fluorine contained polyimide varnish by substituting 6-FDA to BPDA + ODPA.Fig. 1 shows the molecular structure of 6-FDA, BPDA, and ODPA. Low fluorine contained polyimide varnish is composed of 40% 6-FDA, 40% BPDA, 20% ODPA and it showed the excellent characteristics such as the glass transition temperature of 300 deg, the decomposition temperature of 366 deg, the yellow index of 2.2, the coefficient of thermal expansion of 20 ppm/deg, and the transmittance at 550 nm wavelength of 98.1%.Because polyimide substrate made from coating polyimide varnish on carrier glass have to be protected using inorganic barrier material such as SiO2 and Si3N4. Also, transparent electrode is also required to apply voltage to the OLED display. Because the color of the polyimide substrate can be changed with the variation of barrier material thickness and transparent electrode thickness, we used optical simulator, Macleod, to access the transmittance change with the thickness change of SiO2 and Si3N4 as shown in fig. 2. Optimal thickness is selected at SiO2 of 400 nm and Si3N4 of 50 nm. The experimental transmittance is well matched with the simulation transmittance as shown in fig. 3.Fabricated device will be detached using innovative laser lift-off (LLO) that utilized excimer laser which scan the interface between the polyimide substrate and the carrier glass from the backside [2]. Fig, 4 shows the laser irradiation and the detached wrinkle free polyimide substrate. Before the delamination, the polyimide substrate is clear, but shows yellowish color during delamination process. Optimum laser energy for the delamination is compared with the color index as shown in fig. 5.We will make the OLED display on the polyimide substrate. Yi et al., Solar Energy 195, 340 (2020),Bian et al., App. Sur. Sci. 499, 143910 (2020). Figure 1

Synthesis and Stability of Hydrogen Storage Material Aluminum Hydride.

Aluminum hydride (AlH3) is a binary metal hydride with a mass hydrogen density of more than 10% and bulk hydrogen density of 148 . Pure aluminum hydride can easily release hydrogen when heated. Due to the high hydrogen density and low decomposition temperature, aluminum hydride has become one of the most promising hydrogen storage media for wide applications, including fuel cell, reducing agents, and rocket fuel additive. Compared with aluminum powder, AlH3 has a higher energy density, which can significantly reduce the ignition temperature and produce H2 fuel in the combustion process, thus reducing the relative mass of combustion products. In this paper, the research progress about the structure, synthesis, and stability of aluminum hydride in recent decades is reviewed. We also put forward the challenges for application of AlH3 and outlook the possible opportunity for AlH3 in the future.

Effect of desilication of HZSM-5 on the catalytic pyrolysis of polystyrene

Desilicated HZSM-5 (DeHZSM-5) was prepared by the desilication of HZSM-5 (SiO2/Al2O3: 30) and applied to the catalytic pyrolysis of polystyrene (PS) by thermogravimetric analysis (TGA) and pyrolyzer-gas chromatography/mass spectrometry (Py-GC/MS). TGA showed that HZSM-5 lowered the decomposition temperature and apparent activation energies of PS. DeHZSM-5 led a lower decomposition temperature and Ea values than HZSM-5. The main pyrolyzates of PS, styrene monomer, dimer, and trimer, were converted to smaller aromatic hydrocarbons, such as benzene and toluene. The increased pore size and acidity of DeHZSM-5 formed by the desilication of HZSM-5 led to the efficient diffusion of large molecular pyrolyzates with the increased formation of smaller molecular aromatic hydrocarbons confirming the higher catalytic cracking efficiency.

Synthetic and Structural Studies of Ethyl Zinc β-Amidoenoates and β-Ketoiminates.

A set of heteroleptic ethyl zinc β-amidoenoates (1, 2) and β-ketoiminates (3) of the form [LZnEt]2 with varying steric bulk have been synthesised via the reaction of diethylzinc with β-aminoenoate ligands HL1 and HL2 and β-ketoimine HL3. These complexes have been characterised via 1H and 13C NMR, mass spectrometry and single-crystal X-ray diffraction, which unambiguously determined all three structures as dimeric species in the solid state. We observe the unusual dimerisation of 1 and 2 through coordination of the central zinc atom to the methine carbon of the second monomer, which gives these complexes high reactivity. The thermal properties of complex 3 are explored via thermal gravimetric analysis (TGA), to investigate their potential as single-source precursors to zinc oxide, which shows that 3 has a significantly lower decomposition temperature as compared to its bis-ligated counterpart [Zn(L3)2], which gives 3 promise as a single-source precursor to zinc oxide.

Modification of sodium bicarbonate and its effect on foaming behavior of polypropylene

Abstract As a potential physical blowing agent, sodium bicarbonate (SB) is environmentally friendly and low in cost, but its low decomposition temperature cannot meet the requirements of polyolefin foam materials. Herein, for enhancing the thermal properties of SB, a modified way was offered to fabricate various SB-based capsules via suspension polymerization. As the modified SB-based capsules, epoxy resin (EP) accompanied with several organic acids was successfully coated on the surface of SB, serving as heat-insulation layer of SB. Various physicochemical characterizations provided reliable evidences for the good coating effect, and the thermal performance of the modified SB was improved. Further, the composite SB capsules were applied for the foaming of polypropylene (PP), and the foaming behavior of the SB-based capsules in PP was significantly improved, with more uniform distribution, smaller cell diameter, and higher cell density. In all, this work fully proved that the coated shells enhanced the thermal properties of SB, and the modified SB capsules significantly improved the foaming quality of foamed PP.