Semi‐ and full‐interpenetrating polymer networks based on polyurethane produced from canola oil and poly(methyl methacrylate)

Semi‐ and full‐interpenetrating polymer networks (IPNs) were prepared using polyurethane (PUR) produced from a canola oil‐based polyol with primary terminal functional groups and poly(methyl methacrylate) (PMMA). The properties of the material were studied and compared using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and tensile measurements. The morphology of the IPNs was investigated using atomic force microscopy (AFM). Semi‐IPNs demonstrated different thermal mechanical properties, mechanical properties, phase behavior, and morphology from full IPNs. Both types of IPNs studied are two‐phase systems with incomplete phase separation. However, the extent of phase separation is significantly more advanced in the semi‐IPNs compared with the full IPNs. All the semi‐IPNs exhibited higher values of elongation at break for all proportions of acrylate to polyurethane compared with the corresponding full IPNs. These differences are mainly due to the fact that in the case of semi‐IPNs, one of the constituting polymers remains linear, so that it exhibits a loosely packed network and relatively high mobility, whereas in the case of full IPNs, there is a higher degree of crosslinking, which restricts the mobility of the chains. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Interpenetrating polymer networks based on uralkyd–butylmethacrylate

Two-component semi- and full-interpenetrating polymer networks (IPNs) of hydrogenated castor oil based uralkyd resin (UA) and poly(butylmethacrylate) (PBMA) were synthesized by the sequential technique. The elastomers obtained were characterized with respect to their mechanical properties such as tensile strength, elongation at break and hardness (Shore A). The apparent densities of these samples were determined and compared. Glass transition studies were carried out using differential scanning calorimetry. The thermal characterization of the elastomers was undertaken with the aid of thermogravimetric analysis. Phase morphology was studied by scanning electron microscopy. The effect of the variations of UA–PBMA on the above-mentioned properties was examined. The elongation percentage at break showed higher values in the case of all the semi-IPNs as compared to the full-IPNs.     

Epoxy–poly(butyl methacrylate) interpenetrating polymer networks: Morphology and various physical,mechanical, and thermal properties

Semi- and full interpenetrating polymer networks (IPNs) of epoxy resin and poly(butyl methacrylate) (PBMA) were prepared by the sequential mode of synthesis. These were characterized with respect to their mechanical properties, such as ultimate tensile strength, percent elongation at break, and modulus. The densities of these samples were evaluated and compared. Differential scanning calorimetry (DSC) and thermogravimetric analysis were undertaken for thermal characterization of the IPNs. Phase morphology was studied by polarized light microscopy of the undeformed specimens and by scanning electron microscopy of the fractured surfaces of samples undergoing tensile failure. The effects of variations of the blend ratios on the above-mentioned properties were examined. A gradual decrease in modulus and tensile strength was observed for both the semi- and full IPNs with consequent increases in elongation at break and toughness as the proportion of PBMA increased. The densities also followed the same pattern. Semi-IPNs, however, were characterized by higher densities, tensile strengths, and moduli than the corresponding full IPNs. The DSC tracings displayed broadening of transitions, indicating some phase blending. The percent weight retentions in the thermal decomposition of the IPNs and pseudo-IPNs were higher than that observed during the thermal degradation of the epoxy resin homopolymer network. Phase-separated PBMA domains of various sizes were presumed to be responsible for the increased toughness of PBMA-modified epoxy. © 1996 John Wiley & Sons, Inc.     

Morphology,mechanical properties,and failure topography of semi‐interpenetrating polymer networks based on natural rubber and polystyrene

Semi‐interpenetrating networks (semi‐IPNs) were prepared from natural rubber (NR) and polystyrene (PS) by the sequential method. In these semi‐IPNs the NR phase was crosslinked while the PS phase was uncrosslinked. Different initiating systems such as dicumyl peroxide (DCP), benzoyl peroxide (BPO), and the azobisisobutyronitrile (AIBN) system were used for polymerizing the PS phase. The blend ratio was varied by controlling the swelling of NR in the styrene monomer. The mechanical properties of the semi‐IPNs, namely, density, tensile strength, tear strength, elongation at break, tension set, tensile set, impact strength, and hardness, were determined. The morphology of different IPNs was studied using scanning electron microscopy. A compact morphology with a homogeneous phase distribution was observed in the semi‐IPNs. The properties of the semi‐IPN do not change much with the initiating system. However, in most cases, the DCP initiating system showed slightly superior performance. The tensile and tear‐strength values of the IPNs were found to increase with increasing plastomer content. The crosslink density of the semi‐IPNs also increased with increase in the polystyrene content. The experimental values were compared with theoretical models such as series, parallel, Halpin Tsai, Coran, Takayanaki, Kerner, and Kunori. The tensile and tear‐fracture surfaces were examined using a scanning electron microscope. The fracture patterns were correlated with the strength and nature of the failure. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 2327–2344, 2000     

Uralkyd and poly (butyl methacrylate) interpenetrating polymer networks

ABSTRACT:: Hydroxyl terminated alkyds synthesized from castor oil, glycerol, and different dibasic acids were used to develop uralkyds and their interpenetrating polymer networks (IPNs) with polybutyl methacrylate (PBMA). Glass transition temperature measurements gave the evidence of interpenetration. The IPNs were characterized for their physicomechanical properties and their phase morphology was studied by scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). As the concentration of the uralkyd in IPNs increases, a gradual increase in elongation, density, and swelling with a consequent decrease in the hardness were observed for all IPNs. Swelling is relatively more prominent in methyl ethyl ketone (MEK) and toluene than in water. From SEM it was observed that IPNs of PBMA‐uralkyd containing phthalic anhydride (UA‐P) as an acid part showed greater compatibility than those containing dimethyl terephthalate (UA‐D). From thermogravimetric analysis (TGA) no significant change was observed in the degradation behavior of the IPNs. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 825–832, 2000     

Miscibility and properties of semi‐interpenetrating polymer networks based on polyurethane and nitroguar gum

Films from castor oil‐based polyurethane (PU) prepolymer and nitroguar gum (NGG) with different contents (10–70 wt %) were prepared through solution casting method. The networks of PU crosslinked with 1,4‐butanediol were interpenetrated by linear NGG to form semi‐interpenetrating polymer networks (semi‐IPNs) in the blend films. The miscibility, morphology, and properties of the semi‐IPNs coded as PUNG films were investigated with Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, dynamic mechanical thermal analysis, wide‐angle X‐ray diffraction, density measurement, ultraviolet spectroscopy, thermogravimetric analysis, tensile, and solvent‐resistance testing. The results revealed that the semi‐IPNs films have good miscibility over the entire composition ratio of PU to NGG under study. The occurrence of hydrogen‐bonding interaction between PU and NGG played a key role in improvement of the material performance. Compared with the pure PU film, the PUNG films exhibited higher values of tensile strength (11.7–28.4 MPa). Meanwhile, incorporating NGG into the PU networks led to an improvement of thermal stability and better solvent‐resistance of the resulting materials. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104, 4068–4079, 2007     

Sequential interpenetrating polymer networks of novolac resin and poly(2‐ethyl hexyl acrylate)—thermal,mechanical, and morphological study

Interpenetrating polymer networks (IPN) of novolac/poly (2‐ ethyl hexyl acrylate) (PEHA) have been prepared via in situ sequential technique of IPN formation. Full and semi‐IPNs were prepared with different blend ratios (w/w) e.g., 90 : 10, 80 : 20, and 70 : 30 in which the major constituent was novolac resin. A gradual decrease in specific gravity and hardness values was observed with increase in PEHA incorporation. A steady decrease in crosslink density with increase in PEHA fraction in the IPNs was quite evident. The IPNs were characterized with respect to their mechanical properties, e.g., ultimate tensile strength, percentage elongation at break, modulus, and toughness. Thermal behavior was studied by differential scanning calorimetry and thermogravimetric analysis. A plasticizing influence of PEHA on the rigid, brittle, and hard matrix of crosslinked phenolic resin is evidenced from the mechanical and thermal properties. The two‐phase surface morphology is revealed by scanning electron microscope. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Thermal and pH dual‐responsive hydrogels based on semi‐interpenetrating network of poly(N‐isopropylacrylamide) and collagen nanofibrils

Hydrogels with environment‐sensitive properties have great potential applications in the controlled drug release field. In this paper, hybrid hydrogels with semi‐interpenetrating polymer networks (semi‐IPNs), composed of poly(N‐isopropylacrylamide) (PNIPAM) as the thermo‐sensitive component by in situ polymerization and self‐assembled collagen nanofibrils as the pH‐sensitive framework, were prepared for controlled release of methyl violet as a model drug. From Fourier transform infrared spectroscopy and scanning electron microscopy, it was indicated that the crosslinking of PNIPAM in the presence of collagen nanofibrils led to the formation of semi‐IPNs with homogeneous porous structure, and the semi‐IPNs showed improved thermal stability and elastic properties compared with the native collagen as determined using differential scanning calorimetry and rheologic measurements. Furthermore, the semi‐IPNs possessed swelling behaviors quite different from those of neat collagen or PNIPAM hydrogel under various pH values and temperatures. Correspondingly, as expected, the drug release behavior in vitro for semi‐IPNs performed variously compared with that for single‐component semi‐IPNs, which revealed the tunable performance of semi‐IPNs for release ability. Finally the thermo‐ and pH‐responsive mechanism of the semi‐IPNs was illuminated to provide guidance for the application of the thermo‐ and pH‐sensitive collagen‐based hybrid hydrogels in controlled drug delivery systems. © 2019 Society of Chemical Industry     

Engineering properties of poly(vinyl chloride)–poly(butyl methacrylate) semi‐1 and semi‐2 interpenetrating polymer networks

Semi‐1 and semi‐2 interpenetrating polymer networks (IPNs) of poly(vinyl chloride) (PVC) and in situ formed poly(butyl methacrylate) (PBMA) have been synthesized using diallyl phthalate and ethylene glycol dimethacrylate as the crosslinkers of PVC and PBMA, respectively. These were then characterized with reference to their mechanical, thermal, and morphological properties. The mechanical and thermal characteristics revealed modification over the unmodified polymeric systems in relation to their phase morphologies. The semi‐1 IPNs displayed a decrease in their mechanical parameters of modulus and UTS while semi‐2 IPNs exhibited a marginal increase in these two values. The semi‐1 IPNs, however, also revealed a decrease in the elongation and toughness values away from the normal behavior. The thermomechanical behavior of both the systems is in conformity with their mechanicals in displaying the softening characteristics of the system and stabilization over unmodified PVC. The DSC thermograms are also correlated to these observations along with the heterogeneous phase morphology which is displayed by both the systems especially at higher concentration of PBMA incorporation. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Modification of novolac resin by interpenetrating network formation with poly(butyl acrylate)

Interpenetrating networks (IPNs) of novolac (phenol formaldehyde) resin and poly(butyl acrylate) (PBA) were prepared by a sequential mode of polymerization. Both full IPNs and semi‐IPNs of different compositions were synthesized and characterized with respect to their mechanical properties, that is, their modulus, ultimate tensile strength (UTS), elongation‐at‐break percentage, and toughness. Their thermal properties were examined with differential scanning calorimetry and thermogravimetric analysis (TGA). A morphological study was performed with an optical microscope. The effects of the variation of the blend ratios on the aforementioned properties were studied. There was a gradual decrease in the modulus and UTS with a simultaneous increase in the elongation‐at‐break percentage and toughness for both types of IPNs as the proportions of PBA were increased. With increasing proportions of PBA, the glass‐transition temperatures of the different IPNs underwent shifts toward a lower temperature region. This showed a plasticizing influence of PBA on the rigid and brittle phenolic matrix. TGA thermograms depicted the classical two‐step degradation for the phenolic resin. Although there was an apparent increase in the thermal stability at the initial stage (up to 350°C), particularly at lower temperatures, a substantial decrease in the thermal stability was observed at higher temperatures under study. In all the micrographs of full IPNs and semi‐IPNs, two‐phase structures were observed, regardless of the PBA content. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 2407–2417, 2005     

Sequential interpenetrating polymer networks of novolac resin and poly(n‐butyl methacrylate)

Novolac resin/poly(n‐butyl methacrylate), P(n‐BMA), sequential interpenetrating polymer networks (both semi and full types) were prepared and characterization of the various compositions (up to 40% by weight of PF incorporation) was performed in terms of mechanicals, namely, ultimate tensile strength (UTS), percentage elongation at break (% E.B.), modulus, and toughness. Thermal properties were studied by differential scanning calorimetry and thermogravimetric analysis (TGA). Crosslink densities of the IPNs were calculated using Flory‐Rehner equation. The morphological features were studied through scanning electron microscope. There was a gradual decrease of modulus and UTS with consequent increases in % E. B. and toughness with increasing proportions of P(n‐BMA). An inward shifting and lowering of the glass transition temperatures of the IPNs (compared with that of pure phenolic resin) with increasing proportions of P(n‐BMA) were observed. The TGA thermograms exhibit two‐step degradation patterns. A typical cocontinuous bi‐phasic morphology is evident in the micrographs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4030–4039, 2006     

Modification of poly(vinyl chloride) by IPN formation with poly(ethyl acrylate)

Semi‐1 and semi‐2 interpenetrating polymer networks (IPNs) of poly(vinyl chloride) (PVC) and in situ formed poly(ethyl acrylate) (PEA) have been synthesized using diallyl phthalate and ethylene glycol dimethacrylate as the crosslinkers of PVC and PEA, respectively. These two types of IPNs have been compared with respect to their physical, mechanical, and thermal properties and an endeavor has been made to find a correlation of these properties with the morphology generated in these systems. The semi‐1 IPNs displayed a decrease in their tensile strength and modulus while in contrast; the semi‐2 IPNs exhibited a marginal increase with increasing crosslinked PEA incorporation. The semi‐1 and semi‐2 IPNs containing 10 and 30 wt % of PEA displayed a two‐stage degradation typical of PVC in their thermogravimetric and DSC studies while confirming the increased stability of the samples with higher percentages of PEA. The softening characteristics as detected by the extent of penetration of the thermomechanical probe as has been detected by thermomechanical analysis are in conformity with their mechanicals. The biphasic cocontinuous systems as explicit from the morphological studies reveal fibrillar characteristics in both the systems. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Simultaneous full‐interpenetrating polymer networks of blocked polyurethane and vinyl ester. II. Static and dynamic mechanical properties

Simultaneous full‐interpenetrating polymer networks (full‐IPNs) based on blocked polyurethane (PU) and vinyl ester (VE) have been prepared. The static and dynamic properties of these IPNs have been examined. Results show that the tensile strength and flexural strength of IPNs increased with blocked PU content to a maximum value at 7.5 wt % PU content and then decreased. The tensile modulus, flexural modulus, and hardness of IPNs decreased with increasing blocked PU content. The impact strength of IPNs increased with increasing blocked PU content. The tensile strength, flexural strength, tensile modulus, and flexural modulus of IPNs increased with filler (kaolin) content to a maximum value at 20 to 25 phr filler content and then decreased. The higher the filler content, the greater the hardness, and the lower the impact strength of IPNs. The tensile strength, flexural strength, tensile modulus, flexural modulus, and hardness of IPNs increased with increasing VE initiator content. The dynamic technique was used to determined the damping behavior across a temperature range. Results show that the glass transition temperature (T_g) of IPNs are shifted inwardly compared with pure PU and VE, which indicated that the blocked PU–VE IPNs showed excellent compatible. Meanwhile, the glass transition temperature was shifted to a higher temperature with increased filler content. The dynamic storage modulus (E′) of IPNs increased with increasing VE and filler content. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1977–1985, 1999     

Mechanical and dynamic mechanical studies of resol/vinyl acetate‐2‐ethylhexylacrylate/ hexamethoxymethylmelamine interpenetrating network systems

Resol was solution blended with vinyl acetate–2‐ethylhexylacrylate (VAc–EHA) resin in aqueous medium, in varying weight fractions, with hexamethoxymethylmelamine (HMMM) as crosslinker, and data was compared with a control. The present work was aimed at getting an optimum combination of tensile strength, dynamic mechanical strength, impact strength, and toughness by synthesis of an interpenetrating network (IPN) of the resins. The control gave a semi‐IPN system, in which the resol crosslinked, while the acrylic did not, whereas the blend, where HMMM was the crosslinker, gave a full IPN system. Full IPNs of the resol/VAc–EHA system had higher moduli and ultimate tensile strength than the semi‐IPNs. Dynamic mechanical study showed that full IPN systems have higher T_g values than semi‐IPN systems. The impact strength increases with increasing proportions of VAc–EHA copolymer. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 1765–1771, 2003     

Semiinterpenetrating polymer networks based on polyurethane and polyvinylpyrrolidone. I. Thermodynamic state and dynamic mechanical analysis

Semiinterpenetrating polymer networks (semi‐IPNs) based on polyurethane (PU) and polyvinylpyrrolidone (PVP) have been synthesized, and their thermodynamic characteristics, thermal properties, and dynamical mechanical properties have been studied to have an insight in their structure as a function of their composition. First, the free energies of mixing of the two polymers in semi‐IPNs based on crosslinked PU and PVP have been determined by the vapor sorption method. It was established that these constituent polymers are not miscible in the semi‐IPNs. The differential scanning calorimetry results evidence the T_g of polyurethane and two T_g for PVP. The dynamic mechanical behavior of the semi‐IPNs has been investigated and is in accordance with their thermal behavior. It was shown that the semi‐IPNs present three distinct relaxations. If the temperature position of PU maximum tan δ is invariable, on the contrary, the situation for the two maxima observed for PVP is more complex. Only the maximum of the highest temperature relaxation is shifted to lower temperature with changing of the semi‐IPNs composition. It was concluded that investigated semi‐IPNs are two‐phase systems with incomplete phase separation. The phase composition was calculated using viscoelastic properties. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 852–862, 2001     

The effect of alkyd resins on the properties of AA‐NC semi‐IPNs as binders in wood finish

Wood coatings of AA‐NC semi‐interpenetrating polymer networks (semi‐IPNs), made from acid curing amino‐alkyd resins (AA) and nitrocellulose (NC), were prepared by sequential polymerization method. To investigate the effects of oil length on the properties of AA‐NC semi‐IPNs, three grades of alkyd resins (Alkyd) containing 38, 48, and 58% oil were synthesized with phthalic anhydride, glycerol, and soybean oil, employing alcoholysis method. The butylated urea formaldehyde resin (UF) and melamine formaldehyde resin (MF) were also prepared in this study. The AA‐NC semi‐IPNs were maintained at a weight ratio of AA : NC of 25 : 75, where the AA was the composition of MF : UF : Alkyd of 7.5 : 22.5 : 70 (by weight), and 10% of p‐toluene sulfonic acid solution (concentration, 25% in isopropyl alcohol) based on the weight of amino resins was added as acid catalyst. The properties of coatings such as viscosity, drying time, and gel time, and the properties of films including adhesion, hardness, abrasion resistance, impact resistance, tensile strength, released formaldehyde, lightfastness, solvent resistance, and durability were examined. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1923–1927, 2004     

Synthesis and characterization of sequential interpenetrating polymer networks of novolac resin and poly(ethyl acrylate)

Interpenetrating polymer networks (IPN) of Novolac/poly(ethyl acrylate) have been prepared via in situ sequential technique of IPN formation. Both full and semi IPNs were characterized with respect to their mechanical properties that is, ultimate tensile strength (UTS), percentage elongation at break, modulus, and toughness. Physical properties of these were evaluated in terms of hardness, specific gravity, and crosslink density. Thermal behavior was studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The morphological features were observed by an optical microscope. There was a gradual decrease in modulus and UTS, with consequent increases in elongation at break and toughness for both types of IPNs with increasing proportions of PEA. An inward shift and lowering (with respect to pure phenolic resin) of the glass transition temperatures of the IPNs with increasing proportions of PEA were observed, thus, indicating a plasticizing influence of PEA on the rigid, brittle, and hard matrix of crosslinked phenolic resin. The TGA thermograms exhibit two‐step degradation patterns. An apparent increase in thermal stability at the initial stages, particularly, at lower temperature regions, was followed by a substantial decrease in thermal stability at the higher temperature region under study. As expected, a gradual decrease in specific gravity and hardness values was observed with increase in PEA incorporation in the IPNs. A steady decrease in crosslink densities with increase in PEA incorporation was quite evident. The surface morphology as revealed by optical microscope clearly indicates two‐phase structures in all the full and semi IPNs, irrespective of acrylic content. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006     

Thermomechanical properties and morphology of interpenetrating polymer networks of polyurethane–poly(methyl methacrylate)

Interpenetrating networks (IPNs) of polybutadiene‐based polyurethane (PU) and poly(methyl methacrylate) (PMMA) were synthesized. The effect of the incorporation of 2% glycidyl methacrylate (GMA) and 2‐hydroxyethyl methacrylate (2‐HEMA) on the thermal, mechanical, and morphological properties of IPNs was investigated. Both 2‐HEMA and GMA led to improvements in these properties. However, 2‐HEMA‐containing IPNs showed somewhat better tensile strength, elongation, and damping characteristics. The morphology of IPNs containing 2‐HEMA showed better mixing of the components. The improvement in the properties was observed for up to 40% PMMA in the IPNs. Differential scanning calorimetry thermograms showed the presence of three glass transitions. The third glass‐transition temperature was explained by possible grafting of methyl methacrylate onto PU. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1576–1585, 2002     

Radiation synthesis and environmental responsiveness of semi‐interpenetrating polymer networks composed of poly(dimethyl–aminoethyl methacrylate) and poly(ethylene oxide)

Semi‐interpenetrating polymer networks (semi‐IPNs) composed of poly(dimethyl–aminoethyl methacrylate) (PDMAEMA) and poly(ethylene oxide) (PEO) were synthesized by γ‐radiation; three semi‐IPNs with 80 : 20, 90 : 10, and 95 : 5 weight ratios of DMAEMA/PEO were obtained by use of this technique. The gel–dose curves showed that the hydrogels were characterized by a structure typical of semi‐IPNs and the results of elemental analysis supported this point. The temperature‐induced phase transition of semi‐IPNs with the composition of 95 : 5 was still retained, with the lower critical solution temperature of PDMAEMA shifting from 40 to 27°C. The temperature sensitivity of the other two semi‐IPNs gradually disappeared. The pH sensitivity of three semi‐IPNs was still retained but the pH shifted slightly to lower values with increasing PEO content in the semi‐IPNs. The effect of PEO content in semi‐IPNs on their environmental responsiveness was discussed. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 2995–3001, 2004     

Damping analysis of polyurethane/polyacrylate interpenetrating polymer network composites filled with graphite particles

The graphite‐filled polyurethane/poly(methyl methacrylate‐butyl methacrylate) (PU/P(MMA‐BMA)) semi‐interpenetrating polymer networks (IPNs) were synthesized by sequential method. The influences of graphite particle content and size on the 60/40 PU/P(MMA‐BMA) IPNs were studied. The damping properties of IPN composites were evaluated by dynamic mechanical thermal analysis (DMA) and cantilever beam resonance methods. The mechanical performances were investigated using tensile and hardness devices. DMA results revealed that the incorporation of graphite particles improved damping properties of IPNs significantly. The 5% graphite‐filled IPN composite exhibited the widest temperature range and the highest loss factor (tan δ) when the test frequency was 1 Hz. As to the damping properties covering a wide frequency range from 1 to 3,000 Hz, the addition of graphite particles broadened the damping frequency range (Δf, where tan δ is above 0.3) and increased the tan δ value of IPNs. Among them, the composite with 7.5% graphite showed the best damping capacity. And the hardness and the tensile strength of IPN composites were also improved significantly. POLYM. COMPOS., 2013 © 2013 Society of Plastics Engineers