Gas transport properties in (6FDA‐RTIL)‐(6FDA‐MDA) block copolyimides

This article reports synthesis and structure property studies of block copolyimides synthesized using diamino room temperature ionic liquids (RTIL) as diamine monomers. Specifically, polyimide oligomers of different lengths were synthesized using 2,2‐bis (3,4‐carboxylphenyl) hexafluoropropane dianhydride (6FDA) and diamino RTIL (1,3‐di(3‐aminopropyl) imidazolium bis[(trifluoromethyl) sulfonyl] imide). These oligomers were copolymerized with 6FDA and m‐phenylenediamine (MDA) using in situ polymerization to form (6FDA‐RTIL)‐(6FDA‐MDA) block copolyimides. The impact of the length and relative concentration of 6FDA‐RTIL oligomer in the copolymer on the resulting thermal, physical, and gas transport properties was monitored. As the concentration of the 6FDA‐RTIL segments increased, the backbone of the block copolyimides became more flexible resulting in a decrease in the glass transition temperature (T_g) and an increase in the density. The permeabilities of the RTIL containing copolyimides were consistently lower than those of the base polyimide, 6FDA‐MDA, with some increase in selectivities. Interestingly, the permeabilities of films produced with the low molecular weight oligomers were very different than those produced with same composition of the high molecular weight oligomers. This may be indicative of very different morphologies within these copolyimides. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43077.     

Antimicrobial properties and thermal stability of polycarbonate modified with 1‐alkyl‐3‐methylimidazolium tetrafluoroborate ionic liquids

Four water immiscible ionic liquids (ILs): 1‐hexyl‐3‐methylimidazolium tetrafluoroborate, 1‐heptyl‐3‐methylimidazolium tetrafluoroborate, 1‐octyl‐3‐methylimidazolium tetrafluoroborate and 1‐dodecyl‐3‐methylimidazolium tetrafluoroborate have been synthesized. Polycarbonate (PC) films containing ILs were prepared by solvent casting from methylene chloride solutions. Scanning electron microscopy measurements showed the high homogeneity of PC/IL films with the IL content up to 4 wt %. The tendency to IL aggregation was observed for polymeric films with higher IL content (5%). PC/IL composites were found to have the reduced thermal decomposition temperature under both an air and a nitrogen atmosphere in comparison with the neat PC. The effect of IL content on the antimicrobial activity of PC films against Escherichia coli bacteria was studied. Pronounced antimicrobial efficacy was revealed for PC/IL films for all studied ILs starting from 3 wt % of IL. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40050.     

Preparation and dielectric properties of poly(ε‐caprolactone) compounded with “bucky gels”‐like mixture

Poly(ε‐caprolactone) (PCL) was melt compounded with “Bucky gels”‐like mixture that prepared by grinding multiwalled carbon nanotubes (MWNTs) and ionic liquids (ILs). Raman spectrum showed the significant interaction between ILs and MWNTs. The dielectric behavior of PCL nanocomposites based on unmodified and IL‐modified MWNTs was studied from 40 Hz to 30 MHz. The addition of ILs significantly enhanced the dielectric property of PCL/IL/MWNT ternary nanocomposites, which was much higher than that of the sum of PCL/IL with PCL/MWNT binary nanocomposites. The dielectric properties of PCL/IL/MWNT nanocomposites were mainly influenced by ILs in low frequency and were dominated by MWNTs in high frequency. SEM results revealed that a more uniform and fine dispersion of MWNTs were achieved throughout the PCL matrix because of ILs. The addition of ILs in nanocomposites changed the crystallinity of PCL. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40231.     

Composite blending of ionic liquid–poly(ether sulfone) polymeric membranes: Green materials with potential for carbon dioxide/methane separation

The incorporation of imidazolium‐based ionic liquids into a poly(ether sulfone) (PES) polymeric membrane resulted in a dense and void‐free polymeric membrane. As determined through the ideal gas permeation test, the carbon dioxide (CO₂) permeation increased about 22% compared to that of the pure PES polymeric membrane whereas the methane (CH₄) permeation decreased tremendously. This made the CO₂/CH₄ ideal separation increase substantially by more than 100%. This study highlighted the utilization of imidazolium‐based ionic liquids in the synthesis of ionic liquid polymeric membranes (ILPMs). Two different ionic liquids were used to compare the CO₂ separation performance through the membranes. The glass‐transition temperatures (T_gs) of ILPMs were found to be lower than the T_g of the pure PES polymeric membranes; this supported the high CO₂ permeation of the ILPMs due to the increase in PES flexibility caused by ionic liquid addition. The results also draw attention to new trends of ionic liquids as a potential green candidates for future membrane synthesis. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43999.     

Effect of 1‐butyl‐3‐methylimidazolium iodide containing electrospun poly(vinylidene fluoride‐co‐hexafluoropropylene) membrane electrolyte on the photovoltaic performance of dye‐sensitized solar cells

Electrospun poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVdF‐HFP) membrane was prepared from a solution of 16 wt % of PVdF‐HFP containing acetone/N,N‐dimethyl acetamide (7:3 wt %). The prepared electrospun PVdF‐HFP membrane (esPM) was then soaked in ionic liquid electrolyte containing 0.5M LiI, 0.05M I₂ , and 0.5M 4‐tert butylpyridine, 0.5M 1‐butyl‐3‐methylimidazolium iodide (BMImI) in acetonitrile to get electrospun PVdF‐HFP membrane electrolyte (esPME). The effect of various concentrations of BMImI containing esPME on ionic conductivity was studied by AC‐impedance measurements and the diffusion co‐efficients was determined by linear sweep voltammetry. The photovoltaic performance of a DSSC fabricated using 0.5M BMImI containing electrospun PVdF‐HFP membrane electrolyte (0.5M BMImI‐esPME) has power conversion efficiency (PCE) of 6.42%. But the stability of the DSSC fabricated using 0.5M BMImI‐esPME was considerably superior to that fabricated using 0.5M BMImI containing liquid electrolyte (0.5M BMImI‐LE). © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42032.     

Imidazolium‐functionalized norbornene ionic liquid block copolymer and silica composite electrolyte membranes for lithium‐ion batteries

Imidazolium‐functionalized norbornene and benzene‐functionalized norbornene were synthesized and copolymerized via ring‐opening metathesis polymerization to afford a polymeric ionic liquid (PIL) block copolymers {5‐norbornene‐2‐methyl benzoate‐block ‐5‐norbornene‐2‐carboxylate‐1‐hexyl‐3‐methyl imidazolium bis[(trifluoromethyl)sulfonyl]amide [P(NPh‐b ‐NIm‐TFSI)]} with good thermal stability. On this basis, the solid electrolyte, P(NPh‐b ‐NIm‐TFSI)–lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), through blending with LiTFSI, and the nanosilica composite electrolyte, P(NPh‐b ‐NIm‐TFSI)–LiTFSI–SiO₂, through blending with LiTFSI and nanosilica, were prepared. The effects of the PILs and silica compositions on the properties, morphology, and ionic conductivity were investigated. The ionic conductivity was enhanced by an order of magnitude compared to that of polyelectrolytes with lower PIL compositions. In addition, the ionic conductivity of the nanosilica composite polyelectrolyte was obviously improved compared with that of the P(NPh‐b ‐NIm‐TFSI)–LiTFSI polyelectrolyte and increased progressively up to a maximum with increasing silica content when SiO₂ was 10 wt % or lower. The best conductivity of the P(NPh‐b ‐NIm‐TFSI)–20 wt % LiTFSI–10 wt % SiO₂ composite electrolyte with 7.7 × 10^?5 S/cm at 25 °C and 1.3 × 10^?3 S/cm at 100 °C were obtained, respectively. All of the polyelectrolytes exhibited suitable electrochemical stability windows. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44884.     

Copper(I) bromide coordinated by the ionic liquid 1‐[(diethyl amine)amine]ethyl‐3‐methyl imidazolium chloride to catalyze the atom transfer radical polymerization of methyl methacrylate in 1‐allyl‐3‐methyl imidazolium chloride

A coordinating ionic liquid (IL), 1‐[(diethyl amine)amine]ethyl‐3‐methyl imidazolium chloride ([N₃MIM]Cl), was prepared as an alternative to a simple organic ligand to coordinate to copper(I) bromide (CuBr). We, thereby, obtained a novel catalyst for atom transfer radical polymerization (ATRP) reactions. This catalyst was applied to the ATRP of methyl methacrylate in the IL 1‐allyl‐3‐methyl imidazolium chloride ([AMIM]Cl). The chemical structures of the ILs obtained were confirmed by Fourier transform infrared spectroscopy, mass spectrometry, and ¹H‐NMR analyses. The coordination ability of [N₃MIM]Cl was assessed by cyclic voltammetry, and the redox potential of [N₃MIM]Cl–CuBr was ?0.507 V. The [N₃MIM]Cl–CuBr complex was expected to be a markedly more active catalyst than the amine DETA–CuBr complex. The coordination mode toward CuBr was also examined. The [N₃MIM]Cl–CuBr catalyst system showed good controllability in the aforementioned ATRP reaction in [AMIM]Cl. The Cu catalyst was easily separated from the obtained polymer with the coordinating IL as a ligand. Consequently, the coordinating IL overcame the shortcomings of traditional organic ligands, such as poor compatibility with IL media and poor separation of the catalyst from the polymer; this makes it highly promising for applications in the ATRP field. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45484.     

Dissolution and utilization of chitosan in a 1‐carboxymethyl‐3‐methylimidazolium hydrochloride ionic salt aqueous solution

1‐Carboxymethyl‐3‐methylimidazolium hydrochloride ([IMIM–COOH]Cl), a new ionic salt, is proposed as a green, promising solvent for dissolving chitosan. However, because of the optimal dosage of chitosan dissolved in [IMIM–COOH]Cl, a 12 wt % [IMIM–COOH]Cl aqueous solution was selected as an optimum solvent system for dissolving chitosan. The structures of the original and regenerated chitosan were characterized by Fourier transform infrared spectroscopy and X‐ray diffraction analysis. Scanning electron microscopy was used to visualize the morphological features of the reconstituted chitosan membranes. Meanwhile, the absorbance, tensile strength, and breaking elongation of the chitosan membranes were measured. The results reveal that 10–11 wt % was an optimal chitosan concentration for preparing membranes. Furthermore, the adsorption capacity for Cu(II) ion of the chitosan membranes was increased with the chitosan concentration decreased from 12 to 8 wt %. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41965.     

Preparation of polyvinylamine/polysulfone composite hollow‐fiber membranes and their CO2/CH4 separation performance

Fixed‐carrier composite hollow‐fiber membranes were prepared with polyvinylamine (PVAm) as the selective layer and a polysulfone ultrafiltration membrane as the substrate. The effects of the PVAm concentration in the coating solution, the number of coatings, and the crosslinking of glutaraldehyde and sulfuric acid on the CO₂ permeation rate and CO₂/CH₄ selectivity of the composite membranes were investigated. As the PVAm concentration and the number of coatings increased, the CO₂/CH₄ selectivity increased, but the CO₂ permeation rate decreased. The membranes crosslinked by glutaraldehyde or sulfuric acid possessed higher CO₂/CH₄ selectivities but lower CO₂ permeation rates. For the pure feed gas, a composite hollow‐fiber membrane coated with a 2 wt % PVAm solution two times and then crosslinked with glutaraldehyde and an acid solution in sequence had a CO₂ permeation rate of 3.99 × 10^?6 cm³ cm^?2 s^?1 cmHg^?1 and an ideal CO₂/CH₄ selectivity of 206 at a feed gas pressure of 96 cmHg and 298 K. The effect of time on the performance of the membranes was also investigated. The performance stability of the membranes was good during 6 days of testing. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 1885–1891, 2006     

Metal‐chelating properties of poly(2‐hydroxyethyl methacrylate–methacryloylamidohistidine) membranes

Metal‐chelating membranes have advantages as adsorbents in comparison with conventional beads because they are not compressible and they eliminate internal diffusion limitations. The aim of this study was to explore in detail the performance of poly(2‐hydroxyethyl methacrylate–methacryloylamidohistidine) [poly(HEMA–MAH)] membranes for the removal of three toxic heavy‐metal ions—Cd(II), Pb(II), and Hg(II)—from aquatic systems. The poly(HEMA–MAH) membranes were characterized with scanning electron microscopy and ¹H‐NMR spectroscopy. The adsorption capacity of the poly(HEMA–MAH) membranes for the selected heavy‐metal ions from aqueous media containing different amounts of these ions (30–500 mg/L) and at different pH values (3.0–7.0) was investigated. The adsorption capacity of the membranes increased with time during the first 60 min and then leveled off toward the equilibrium adsorption. The maximum amounts of the heavy‐metal ions adsorbed were 8.2, 31.5, and 23.2 mg/g for Cd(II), Pb(II), and Hg(II), respectively. The competitive adsorption of the metal ions was also studied. When the metal ions competed, the adsorbed amounts were 2.9 mg of Cd(II)/g, 14.8 mg of Pb(II)/g, and 9.4 mg of Hg(II)/g. The poly(HEMA–MAH) membranes could be regenerated via washing with a solution of nitric acid (0.01M). The desorption ratio was as high as 97%. These membranes were suitable for repeated use for more than three adsorption/desorption cycles with negligible loss in the adsorption capacity. The stability constants for the metal‐ion/2‐methacryloylamidohistidine complexes were calculated to be 3.47 × 10⁶, 7.75 × 10⁷, and 2.01 × 10⁷ L/mol for Cd(II), Pb(II), and Hg(II) ions, respectively, with the Ruzic method. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1213–1219, 2005     

Thin film composite forward osmosis membranes with poly(2‐hydroxyethyl methacrylate) grafted nano‐TiO2 as additive in substrate

The poly(2‐hydroxyethyl methacrylate) grafted titanium dioxide nanoparticles were synthesized and added to the substrate of flat‐sheet thin film composite forward osmosis (TFC‐FO) membranes. The hydrophilicity of substrate was improved, which was advantageous to enhance the water flux of TFC‐FO membranes. The membranes containing a 3 wt % TiO₂‐PHEMA in the substrate exhibited a finger‐like structure combined with sponge‐like structure, while those with lower or without TiO₂‐PHEMA content showed fully finger‐like structures. As for FO performance, the TFC‐FO membranes with 3 wt % TiO₂‐PHEMA content achieved the highest water flux of 42.8 LMH and 24.2 LMH against the DI water using 2M NaCl as the draw solution tested under the active layer against draw solution (AL‐DS) mode and active layer against feed solution (AL‐FS) mode, respectively. It was proven that the hydrophilic property of membrane substrates was a strong factor influencing the water flux in FO tests. Furthermore, the structural parameter was remarkably decreased with an increase of TiO₂‐PHEMA content in membrane substrate, indicating the reducing of internal concentration polarization. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43719.     

Ion‐exchange membrane based on poly(styrene sulfonic acid‐co‐n‐(2‐hydroxyethyl) acrylamide)

A new ion‐exchange membrane was prepared by blending a copolymer of poly(styrene sulfonic acid‐co‐N‐(2‐hydroxyethyl) acrylamide) with poly(vinylidene fluoride). The dissolution of the copolymer into water was prevented by the crosslinked network formed by condensation reaction between N‐(2‐hydoroxyethyl) acrylamide (HEAA) units. The reaction was caused after film‐forming the blend. Swellability in water, ion‐exchange capacity, ion conductivity, and mechanical properties of the membrane were investigated and compared with those of a well‐known ion‐exchange membrane, Nafion 117. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2788–2796, 2007     

Gas permeation and separation properties of polyimide/ZSM‐5 zeolite composite membranes containing liquid sulfolane

The preparation, characterization, and gas permeation properties of novel composite membranes containing polyimide (PI), liquid sulfolane (SF), and zeolite (ZSM‐5) were investigated to address the interface defects between the PI and the zeolite. The free‐standing composite membranes were prepared by the solvent casting method. The gas permeability of the PI+ZSM‐5 membrane was higher than that of PI, whereas its gas selectivity was significantly reduced, suggesting that these results are attributed to the interface defects. The CO₂ selectivity of PI+ZSM‐5+SF was higher than those of the PI+ZSM‐5 membranes because of the introduction of liquid SF into the interface defects. Furthermore, liquid SF enhanced the CO₂/H₂ selectivity near the recent upper bound. Therefore, the use of liquid SF could be an effective approach to preventing interface defects and increasing the CO₂ selectivity, particularly for CO₂/H₂. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

High‐strength regenerated cellulose fibers spun from 1‐butyl‐3‐methylimidazolium chloride solutions

High‐performance regenerated cellulose fibers were prepared from cellulose/1‐butyl‐3‐methylimidazolium chloride (BMIMCl) solutions via dry‐jet wet spinning. The spinnability of the solution was initially evaluated using the maximum winding speed of the solution spinning line under various ambient temperatures and relative humidities in the air gap. The subsequent spinning trials were conducted under various air gap conditions in a water coagulation bath. It was found that low temperature and low relative humidity in the air gap were important to obtain fibers with high tensile strength at a high draw ratio. From a 10 wt % cellulose/BMIMCl solution, regenerated fibers with tensile strength up to 886 MPa were prepared below 22 °C and relative humidity of 50%. High strengthening was also strongly linked with the fixation effect on fibers during washing and drying processes. Furthermore, an effective attempt to prepare higher performance fibers was conducted from a higher polymer concentration solution using a high molecular weight dissolving pulp. Eventually, fibers with a tensile strength of ～1 GPa and Young's modulus over 35 GPa were prepared. These tensile properties were ranked at the highest level for regenerated cellulose fibers prepared by an ionic liquid–based process. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45551.     

Synthesis of porous Al2O3‐PVDF composite separators and their application in lithium‐ion batteries

In this article, a modified tape casting method is employed by dispersing and ball milling of Al₂O₃ powders in the poly (vinylidene fluoride) polymer, with the aim of developing uniform nanocomposite separators in the lithium‐ion cell system. The surface morphology, pore structure, heat‐resisting property, infrared property, and cell performance of the nanocomposite separators are investigated. The experimental results indicate that ball milling plays an important role in yielding homogeneous, porous nanocomposite separator membranes. The developed separator membranes exhibit high thermal stability and excellent electrochemical performance, therefore, are promising for use in the lithium‐ion cell systems. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 2886–2890, 2013     

Fabrication and Characterization of Glass Fiber Reinforced Composites from 2,3‐Epoxypropyl 3‐(2‐Furyl)acrylate and Acrylonitrile

The present paper comprises synthesis and characterization of 2,3‐epoxypropyl 3‐(2‐furyl)acrylate (EPFA) from 3‐(2‐furyl)acrylic acid (FAA) and epichlorohydrin, and its subsequent copolymerization with acrylonitrile (AN) by varying the ratio of EPFA:AN and time using benzoyl peroxide as initiator at 80°C in toluene. The resultant pre‐polymers were characterized by epoxy equivalent weight (EEW), viscosity measurement, gel permeation chromatography (GPC), and infrared (IR) spectral studies. The prepolymers were cured by employing two different curing agents viz. chlorosulfonic acid (ClSO₃H) and maleic anhydride/triethanolamine (MAN : TEA). The curing study was performed isothermally at 120 and 160°C, respectively, for the agents employed. Differential scanning calorimetry (DSC) was also employed to study the curing behavior on dynamic runs. The cured samples were analyzed by thermogravimetry for their thermal stability. The glass fiber reinforced composites (GFRC) were fabricated from selected resin samples and were characterized for their mechanical properties, electrical properties and chemical resistance.     

Ternary proton exchange membranes with low‐cost raw materials: Solvent type influence on microstructure development,high ionic conductivity,and ionic liquid lixiviation protection

A critical stage of solvent evaporation during membrane casting was identified as responsible for significant differences in performance of ternary membranes composed of PEEK with 73% of sulfonation degree. DemaTfO and MmtdemaDMF showed to be the best solvent for casting of membranes prepared through the present study, which is against the observations made through other different studies. Fractal structures are formed regardless of solvent polarity, and interlamellar spacing is found to be higher when DMF is used, which led to higher conductivity and IL leaching protection. Proton relaxometry showed that only the membranes made with DMF and DMAc possess one single mobility domain. Transmission electron microscopy micrographs showed a higher damage in membranes with two different mobility domains and consequent phase separation. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46012.     

Imidazolium ionic liquid incorporation on sulfonated poly(styrene‐isobutylene‐styrene) proton exchange membranes

Ionic liquids (ILs) with different anions and cations were incorporated in sulfonated poly(styrene‐isobutylene‐styrene) (SIBS) to modify its chemical, morphological, and transport properties for direct methanol fuel cell (DMFC) applications. Different loadings of IL and different solvents were studied to have a better understanding of the incorporation process and the ability of the solvent to affect the interaction of the IL with the sulfonated polymer. Morphological characterization with SAXS and AFM suggested changes caused by the incorporation of the IL and by the solvent used. FT‐IR spectra showed small variations in energy related to interactions of the IL with the sulfonic groups which caused thermogravimetric stabilization of the ionic domains. Other results suggest that water has a very significant effect on the morphology, interaction with the IL, and transport properties of the membranes. Optimal concentration of IL (～10 mol %) provides enough water to produce efficient proton conductivity (0.15 S/cm) and minimal methanol permeability (0.8 × 10^?6 cm²/s). © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44900.     

Preparation of hydrophilic dimethyl 5‐sodium sulfoisophthalate/poly(ethylene terephthalate) nanofiber composite membranes for improving antifouling properties

In this study, the effect of dimethyl 5‐sodium sulfoisophthalate (SSI) nanoparticles (NPs) on the antifouling properties of poly(ethylene terephthalate) (PET) electrospun nanofiber membranes (ENMs) was investigated through the ultrafiltration of C. I. Basic Blue 3. 3 dye. To reveal the tortuous effect of this additive on the antifouling properties, scanning electron microscopy was used for the characterization of the ENM structure and the optimization of the SSI NP content. Then, some selected physical and structural properties of the membrane, such as the porosity, moisture regain, contact angle, hydraulic permeability (L _p ), and mechanical properties, in the optimized range of SSI NP contents were investigated. Finally, the influence of this additive on the rejection and flux recovery ratio of the prepared membranes was considered. Consequently, the antifouling properties were assessed with consideration of all of the aforementioned parameters. The SSI/PET2 membrane (that with 0.02% w/w SSI NPs with respect to the total amount of PET polymer and SSI NPs), with an average nanofiber diameter of 450 nm, a porosity of 78.44%, a moisture regain of 9.34%, a contact angle of 86.48°, an L _p of 42,167 L h^?1 m^?2 bar^?1, a tensile strength of 4.66 ± 0.04 MPa, a flux recovery ratio of 15.3%, and a final rejection of 95%, showed a significant enhancement in the antifouling properties compared with pristine PET ENMs. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44522.     

All‐wood biocomposites by partial dissolution of wood flour in 1‐butyl‐3‐methylimidazolium chloride

After cedar‐derived wood flour (WF) and bark flour (BF) were mixed with 1‐butyl‐3‐methylimidazolium chloride (BMIC) at 100°C, the obtained compounds with BMIC content 40 wt % were compression‐molded at 210°C to give WF/BMIC and BF/BMIC composites, respectively. The BMIC contained in the composites was twice extracted with ethanol at 60°C to afford WF/BMIC‐E and BF/BMIC‐E biocomposites, which were subsequently annealed at 200°C for 24 h to produce WF/BMIC‐A and BF/BMIC‐A biocomposites. The Fourier transform infrared spectroscopic analysis revealed that WF has a higher content of cellulose and a lower content of lignin than BF does, and that the BMIC content diminished by the extraction process. The scanning electron microscopy analysis showed that woody particles joined together by the compression molding of WF/BMIC and BF/BMIC compounds, and that the extraction of BMIC roughened the surface and the annealing again smoothed the surface due to the fusion of the residual BMIC and woody particles. The XRD measurements indicated that the annealing enhanced the crystallinity of cellulose component. The tensile properties and 5% weight loss temperature of the biocomposites were considerably improved by the extraction of BMIC and further by the annealing. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013