Interpenetrating Polymer Network Composites Research Articles

A Tribological investigation of fly ash particulate‐loaded E‐glass fiber reinforced interpenetrating polymer network composites

AbstractEnvironmentally‐friendly materials are increasingly sought in use of both structural and non‐structural applications. Most of the prominent places, particulates and fibers are exclusively utilized to reinforce polymeric composites, aiming to enhance their strength and provide effective protection against wear. Currently, one of the most pressing issues encountered in current industries are wear and tear, mostly happens during manufacturing and agricultural operations. To overcome this issue, the current study examines into exploring the effects of different weight ratios (0%, 1%, 3%, 5%, 7%, 9% by wt.%) of fly ash (FA) loading on the abrasive characteristics of Interpenetrating Polymer Networks (IPNs) composites strengthened with E‐Glass fibers. Abrasion tests, conducted in accordance with ASTM D99 standard which involves five control parameters: load, FA content, speed, sliding distance, and surface roughness. Experimental design utilized Taguchi's orthogonal array (L25), with opts ANOVA to identify significant control factors. Results indicate that the addition of FA substantially enhances the wear resistance of particulate‐loaded E‐Glass fiber reinforced IPN composites. Moreover, the specific wear rate is significantly influenced by the applied load and FA content. However experimental data suggests that optimal wear behavior for IPN composites occurs under the conditions of 50 N load, 3% FA content, 300 rpm speed, 4000 m sliding distance, and 0.3 μm disc roughness. Further, scanning electron microscopy was also employed to examine microstructural details to better know the micro‐mechanism behavior happens between the particulates with fiber and matrix reinforcement.Highlights Utilization of fly ash significantly enhances composite strength. IPN laminates fabricated with 0%–7% particulate loads. IPN laminates thoroughly evaluated through wear testing. DOE guided experimental design using L25 orthogonal array. SEM analysis reveals superior quality of fly ash‐loaded IPN.

Effect of hygrothermal aging on novel hybrid composites: Transforming textile waste into a valuable product

AbstractThe textile industry now produces thousands of tons of waste worldwide, and the total amount of discarded material waste increases yearly. Hygrothermal aging of cotton/E‐glass (hybrid) fiber reinforced with various proportions of graphene oxide (0%, 1%, 3%, 5%, 7%, and 9%) was performed. Epoxy and vinyl ester (50:50) have been chosen because of the Interpenetrating Polymer Networks (IPNs) concept. Laminates were subjected to 50, 60, and 70°C temperatures for 180 days. Further, Tg and the degree of cross‐linking have been determined by using differential scanning calorimetry (DSC). DSC analysis proves that a hot water bath enhances the cross‐linking of the polymer. IPN laminates were also intermittently weighed for water uptake, and their consecutive mechanical properties like tensile, flexural, and impact strength were obtained. From this work, it was observed that the addition of 5 w.t% graphene oxide in cotton/E glass fiber vinyl ester/epoxy resin hybrid IPN composites showed a tensile strength of 375.61 MPa, flexural strength of 393.54 MPa, Interlaminar shear strength (ILSS) of 49 MPa and the impact strength of 22.54 MPa. Moreover, the lowest inclusion of particulate addition exhibits better mechanical properties than (up to 5% of GO) the highest particulate loading into the matrix. SEM study was conducted on the broken specimens to know the impact of diffusion characteristics on the physical properties of the IPN composites.Highlights Natural and synthetic fibers are used as reinforcements. Waste cotton/E glass fiber vinyl epoxy composites are fabricated. Laminates were subjected to diverse temperatures for 180 days. The moisture diffusion coefficient is proportional to water temperature. Bathtub temperature affects the tensile strength of the laminate.

Interpenetrating Polymer Networks of Poly(2-hydroxyethyl methacrylate) and Poly(N, N-dimethylacrylamide) as Potential Systems for Dermal Delivery of Dexamethasone Phosphate.

In this study, a series of novel poly(2-hydroxyethyl methacrylate) (PHEMA)/poly(N,N'-dimethylacrylamide) (PDMAM) interpenetrating polymer networks (IPNs) were synthesized and studied as potential drug delivery systems of dexamethasone sodium phosphate (DXP) for dermal application. The IPN composition allows for control over its swelling ability as the incorporation of the highly hydrophilic PDMAM increases more than twice the IPN swelling ratio as compared to the PHEMA single networks, namely from ~0.5 to ~1.1. The increased swelling ratio of the IPNs results in an increased entrapment efficiency up to ~30% as well as an increased drug loading capacity of DXP up to 4.5%. X-ray diffraction (XRD) and differential scanning calorimetry (DSC) show the formation of a solid dispersion between the drug DXP and the polymer (IPNs) matrix. Energy-dispersive X-ray (EDX) spectroscopy shows an even distribution of DXP within the IPN structure. The DXP release follows Fickian diffusion with ~70% of DXP released in 24 h. This study demonstrates the potential of the newly developed IPNs for the dermal delivery of DXP.

A study on physical and morphological properties of novel bio-cotton/E-glass fiber–reinforced vinyl ester/epoxy resin hybrid interpenetrating polymer networks composites

A study on physical and morphological properties of novel bio-cotton/E-glass fiber–reinforced vinyl ester/epoxy resin hybrid interpenetrating polymer networks composites

Long term accelerated influence on thermo-mechanical properties of glass/carbon fiber reinforced interpenetrating polymer network hybrid composites

The prime importance of this work is that to compare the influence of hygrothermal analysis on the physical properties of different variant of interpenetrating polymer network (IPN) blend reinforced with E-Glass/Carbon and combination of both (hybrid) fibers. In this study, combinations of epoxy (EP)/polyurethane (PU), vinyl ester (VER)/polyurethane (PU), and epoxy (EP)/vinyl ester (VER) have been taken as the matrix material (IPN) to reinforce the glass, carbon, and combination of both fibers. Moreover, prepared specimens are subjected with boiling water immersion test by maintaining the temperature of 45°C, 55°C, and 65°C in order to thoroughly understand the influence of moisture absorption and temperature in their physical attribution as per ASTM standards. Besides, to better understand the thermal stability and compatibility, thermal-gravimetric (TGA) analysis and burn-off test were conducted as well. During this study, it was found that, combination of VER/PU possesses the high moisture absorption resistance amongst all variants (0.725% for 45°C, 0.854% for 55°C, 1.234 for 65°C). Similarly, epoxy/vinyl ester reinforced glass fiber IPN laminate (EVG) has shown notable TGA value as 418.6°C, as well burn-off test also shown that hybrid IPN composites have better wettability (less void presence) than all other laminates (EPGC-0.9%, VPGC-0.89%, EVGC-0.92%). Further, losses of physical strengths have been noticed on all specimens upon subjection on hygrothermal environment irrespective of IPN blend and fiber constituents.

Zeolite‐Reinforced Interpenetrating Polymer Network Initiated by Chalcone Based Photoinitiating System and Their Application in 3D/4D Printing

AbstractWith the rapid development of photopolymerization, the search for new near‐UV/visible light sensitive photoinitiating system (PIS) is one of the most interesting topics in polymerization area. In this work, a new PIS (chalcone dye/amine/iodonium salt) could efficiently and simultaneously initiate the free radical photopolymerization of polyethylene glycol diacrylate (PEGDA) and the cationic photopolymerization (CP) of 3,4‐epoxycyclohexylmethyl‐3,4‐epoxycyclohexanecarboxylate (EPOX) upon LED@405 nm irradiation to obtain interpenetrating polymer network (IPN). Furthermore, this PIS was employed in the photopolymerization of LTA‐5A zeolite filled interpenetrating polymer network composites (IPN, PEGDA/EPOX). Compared to the pure IPN, the depth of cure (DOC) for IPN with 50 wt% LTA‐5A remarkably increased by ca. 90%, which was the first time reported that DOC could increase with the increase of the filler content. 3D patterns with good resolution were manufactured through direct laser write technique, and those with high filler contents showed good water swelling property. Under hydrothermal stimuli, IPN composite with 50 wt% LTA‐5A exhibited a good 4D printing behavior. Therefore, not only this chalcone dye has a good photoinitiation ability for photopolymerization, but also the resulting IPN composites prepared with the photoinitiating system containing this dye have potential applications for 3D/4D printing and composites preparation.

Investigation of TiO2 Nano Filler in Mechanical, Thermal Behaviour of Sisal/Jute Fiber Reinforced Interpenetrating Polymer Network (IPN) Composites

In this work, various proportionate (0%, 1%, 3% 5% & 7%) of titanium di-oxide nano-filler was utilized as particulate matter along with the sisal/jute fiber reinforcement, in the view to increase the physical properties of the composite materials. Beside, as matrix material the mixture of Epoxy (E) and Polyurethane (PE) was chosen with the proportionate of 70 and 30 wt.% respectively, in order to extract the specific qualities of both the matrices to achieve the interpenetrating polymer networks (IPNs). Moreover, to exactly find out the thermo-mechanical characteristics of the sisal/jute fiber reinforced IPN composites, tests like thermo-gravimetric analysis (TGA), tensile, flexural, Impact, short beam strength and water absorption tests were carried out as per standards. It was found that, incorporation of 5% of TiO2, increases the mechanical properties such as tensile, flexural, impact and short beam strength. Similarly, incorporation of TiO2 into IPN matrix enhances the thermal stability and water absorption resistance. All the obtained values of various filler weight % of TiO2 were compared with each other against with and without particulate incorporated IPN laminate in the purpose of using the same in construction industries.

A Study on Mechanical and Morphological Analysis of Banana/Sisal Fiber Reinforced IPN Composites

In this present study, untreated and (5 % NaOH) treated banana and sisal fiber was chosen as the reinforcement along with the various proportionate of polyurethane (PU) loading into vinyl ester (VER) as interpenetrating polymer networks (IPNs) laminate. In this study, banana/sisal (untreated/treated) fiber reinforced IPN laminate was fabricated with the following variant of 0 %, 20 %, 40 % PU loading by using the compressing molding process. Mechanical tests such as tensile, flexural, impact, hardness and water absorption tests were performed and compared in accordance with ASTM standards, to determine their inter-laminar strength of the IPN laminate. In addition, interfacial analysis was also carried out with the help of the scanning electron microscope (SEM) on the broken specimens in order to thoroughly understand the fractured specimen’s micro-structural behavior. Among all tests, the sisal fiber reinforced IPN laminate showed significant surge in all physical tests expects moisture absorption characteristics.

Mechanical performance of vinyl ester—polyurethane interpenetrating polymer network composites

AbstractIn this study, a carbon fiber/vinyl ester‐polyurethane interpenetrating polymer network (IPN) laminate composite was fabricated and characterized for the first time. The IPN matrix, consisting of a commercially available vinyl ester and polyurethane, was synthesized via a sequential method with vinyl ester as the rigid phase and polyurethane as the flexible phase. Good compatibility between the two phases in the matrix was achieved and confirmed via differential scanning calorimetry and dynamic mechanical analysis. The thermomechanical response of the IPN matrix was compared with that of an unmodified vinyl ester resin. The presence of the more ductile polyurethane in the IPN matrix depressed the glass transition temperature (from 94 to 84°C), but also served to improve damping response at all frequencies studied. Tensile and flexural tests were performed on the carbon fiber/IPN and carbon fiber/vinyl ester composites to determine their mechanical response. The IPN composite exhibited lower tensile properties than the vinyl ester composite. However, its flexural properties were on par with those of the vinyl ester composite.

Experimental investigation on physical properties of banana/E-glass fiber reinforced hybrid interpenetrating polymer network composites

Researchers are often trying to find out the various renewable energy sources to continuously feed the growing energy demands Now a day’s researchers are much interested to carry out their investigation in the area of finding out the various eco friendly materials in order to completely or partially eliminate the usage of conventional of type of materials, as well as to avoid the environmental pollution. In this particular study, the six combinations (E-Glass/Banana fiber reinforcement) of interpenetrating polymer network laminate have been fabricated and their physical strengths were examined with help of the tensile, flexural, impact and moisture absorption test as per the ASTM standards. The results showed that, the neat E-Glass fiber reinforced IPN laminate exhibited the tensile physical strength value as 212.42 MPa, flexural strength of 3.2 kN, impact strength value of 4.62 J and finally water uptake percentage was 1.8%. Whereas the IPN laminate comprises of banana fiber and E-glass fiber hybridization has shown the (60 wt of E-Glass/40 wt of banana) tensile strength value as 179.53 MPa, flexural strength value of 2.12 kN, impact strength value of 4.12 J and moisture absorption percentage was 8.53%. All the test results were compared with each other and significant contribution of the hybridisation is presented in this study.

A study on sliding wear behaviour of carbon fiber reinforced IPN composites

Carbon fiber usage is keep on increased in most of the industrial applications due to its light weight, high weight to stiffness ratio, high tensile strength, chemical resistance, low thermal expansion, high – temperature tolerance and low weight. Their uses mostly evidenced in nearly all of the applications like aerospace, military, motorsports, civil engineering applications. In this present study, carbon fiber is loaded with different proportions of alumina (0%, 10%, 15% and 20%) as filler in the presence of interpenetrating polymer networks (IPN – vinylester/polyurethane), as matrix material. The physical properties of the carbon fiber loaded interpenetrating polymer networks (IPNs) with alumina filler (particulate) have been thoroughly investigated as per ASTM standards. Besides that to completely know about the influence of coating of nickel on carbon fiber and loading of alumina filler on wear characteristics, through the pin-on disc the wear analysis were carried out. It is evidenced that the alumina filled carbon fiber (uncoated) reinforced IPN composite has shown noteworthy raise in wear resistance. Similarly the nickel coated carbon fiber, alumina loaded IPN composites as well have shown the very good wear resistance characteristics.

Short silica fibre-reinforced polymethylsilsesquioxane–phenolic interpenetrating networks: exploration for use as ablative thermal protection system in aerospace

Short silica fibre-reinforced simultaneous interpenetrating polymer network (IPN) composites consisting of polymethylsilsesquioxane (PMSQ) and phenol–formaldehyde resin were prepared through thermal cross-linking. Such IPN composites combine the advantageous ablative features of individual systems and excellent thermal insulation aspects. IPNs were prepared with varying composition between PMSQ and PF, at constant fibre content (60% by weight). The influence of IPN composition on the ablation and out-gassing characteristics was explored in detail. Arc-jet evaluation brought out the superior thermal shock resistance of IPN composites that were richer in PMSQ content. Further, it was inferred that the mechanism of thermal protection shifted to ablative heat shielding with increase in PF content. Microstructural characterization of the arc plasma eroded specimens was carried out using FTIR and Raman spectroscopy to understand the chemical mechanism of erosion process. Higher PMSQ content facilitated the formation of SiOC glass, whereas higher PF content resulted in well-defined char layer comprised of predominantly pyrolytic carbon. Higher PMSQ content also favoured lower out-gassing properties. The study brought out the superior thermal protection capability of the IPN with respect to aerospace applications.

Interpenetrating Polymer Network Microgels in Water: Effect of Composition on the Structural Properties and Electrosteric Interactions.

Microgels of cross-linked interpenetrating polymer networks (IPNs) are very versatile systems combining the properties of colloids and polymers. Herein we study IPN microgels composed of poly(N-isopropylacrylamide) and poly(acrylic acid) to understand how weight composition and reactant concentrations affect their structural, conformational and electrosteric properties in water. The results show that it is possible to drive the formation of microgels with the desired properties by adjusting IPN composition and preparation method during the synthesis. During synthesis, the polymerization of acrylic acid triggers the merging among IPNs via covalent linking, giving rise to microgels with larger mass and size, the effect being larger for higher concentration of the reactants. In addition, a close relation between the microgel internal conformation and the colloidal stability is observed, due to the presence of screened groups inside the microgel.

Short silica fiber composites with simultaneous interpenetrating polymer networks constituted by siloxane and phenolic systems

Short silica fiber reinforced simultaneous interpenetrating polymer network (IPN) composites comprising of siloxane and resole phenolic units were synthesized through curing of polymethylsilsesquioxane (PMSQ) and phenolic polymer systems along with short silica fibre. IPNs were formed at various PMSQ/phenolic ratios, while weight percentage of silica short fiber was kept at 60% (by weight). The formation of IPN was confirmed by FTIR, TGA and DMA. The effect of IPN composition on the mechanical, thermal, thermo‐physical and dynamic mechanical properties was investigated. The variation in properties was well correlated with the morphological and phase distribution features of IPN and the interaction of matrix with silica fiber. It was found that phenolic addition improved the properties of PMSQ‐silica composite system substantially and the optimal obtained was with 25% phenolic for most of the properties (compressive and flexural strength, toughness and thermal conductivity) due to the complete miscibility of the resultant IPN and its superior interaction with silica fiber. Tensile strength and impact strength showed increasing trend with phenolic content. However, the char residue got decreased with increase in phenolic content. This study shows that the synergy of PMSQ and PF polymeric systems in the form of IPN is worthwhile to be explored further for various potential applications. POLYM. COMPOS., 39:4010–4019, 2018. © 2017 Society of Plastics Engineers

Physical Properties of Micro Hollow Glass Bead Filled Castor Oil-Based Polyurethane/Epoxy Resin IPN Composites

ABSTRACTA series of micro hollow glass beads (HGB) filled castor oil-based polyurethane/epoxy resin graft interpenetrating polymer network (IPN) composites were prepared. The tensile and impact strengths, impact fractured surfaces, damping properties and thermal stability of the IPN composites were studied systematically in terms of composition. Results revealed that the addition of HGB into polyurethane/epoxy IPN can significantly improve not only the tensile strength but also the impact strength. The tensile strength was increased by 61% and at the same time the impact strength was increased by 25% when the HGB content was 1.5%. The damping properties were better than the composition of 0.5% or 2% HGB content when the HGB content was 1% or 1.5%. The thermal decomposition temperature was also slightly improved by the incorporation of HGB. It is suggested that the HGB reinforced polyurethane/epoxy resin IPN composites could be used as structural damping materials.

A Study on the Preparation of Epoxy - Modified Polyurethane Foam and its Adhesive Properties

Epoxy resin (EP) modified polyurethane prepolymer (PUP) was prepared by synthesizing prepolymer method, and then EP/PU interpenetrating polymer networks (IPN) composites was produced with better adhesive properties as the foam expands further. The effects of the process on graft reaction and spatial structure of EP/PU IPN composites was studied by FT-IR and scanning electron microscopy (SEM). And a study on the adhesive properties of polyurethane foams with different content of epoxy resins was done by adhesion strength test. The adhesive strength of the IPNs composites were significantly improved when the EP content was 50%. The thermal stability and the expansion ratio of EP/PU IPNs composites were reduced slightly. The modified IPN composites were expected to be used as the preparation of high viscosity and high dilatability of the special - purpose materials in future.

Interpenetrating polymer network composites containing polyurethanes designed for vibration damping

The paper is a literature review concerning the interpenetrating polymer network (IPN) composites containing polyurethanes that can be used for vibration damping in marine vehicles. The effects of filler introduction on damping, mechanical and thermal properties of IPN are compared. The addition of filler affects all relevant properties, in dependence on the filler type and quantity. Damping enhancement is achieved by introduction of each of studied fillers. The ability to optimize IPN structure and filler incorporation provides a way to obtain a material with desired features.

Temperature-induced phase transition in hydrogels of interpenetrating networks of poly(N-isopropylacrylamide) and polyacrylamide

Collapse transition in hydrogels of interpenetrating polymer networks (IPNs) of thermoresponsive poly(N-isopropylacrylamide) (PNIPAm) and hydrophilic polyacrylamide (PAAm) was studied by a combination of NMR spectroscopy, small-angle neutron scattering (SANS) and DSC. The influence of IPNs composition and preparation on the phase transition was examined with respect to possible application of these responsive materials for drug delivery and molecular separation. Heterogeneous nature and an existence of compact globular structures with gyration radius ∼20nm was revealed in all investigated IPN hydrogels by SANS. The increasing content of PAAm component in IPNs shifts the transition toward higher temperatures and the fraction pmax of polymer units with significantly reduced mobility detected by NMR as well as the enthalpy change ΔH in DSC measurements are reduced. Reversed order of adding components during IPNs preparation also significantly affects parameters of the phase transition and collapsed structures. IPN PAAm/PNIPAm 42/58 shows substantially reduced ΔH values of the transition in comparison with IPNs PNIPAm/PAAm. A certain portion of water (HDO) bound in globular structures was established from measurements of 1H NMR spectra and spin–spin relaxation times T2 in all PNIPAm/PAAm collapsed hydrogels and in collapsed hydrogel of the neat PNIPAm, while bound water was not detected by NMR in PAAm/PNIPAm hydrogel. A slow exchange regime between bound and free water was revealed in most cases. T2 relaxation times of bound HDO are then up to one order of magnitude smaller in comparison with “free” HDO. Interestingly enough, the bound HDO appears already at temperatures when polymer segments just begin to form collapsed structures. The fraction of bound water slowly decreases with time.

Preparation, Damping and Thermal Properties of Castor Oil-Based Polyurethane/Poly(Methyl Methacrylate-Butyl Methacrylate-Styrene) Grafted Interpenetrating Polymer Networks

A series of castor oil-based polyurethane (PU)/poly (methyl methacrylate-butyl methacrylate-styrene) (PA) grafted interpenetrating polymer networks (IPNs) were prepared. The effect of composition of the IPNs on the damping, thermal and mechanical properties were studied systematically. PU/PA (60:40, weight ratio) IPNs with methyl methacrylate/butyl methacrylate/styrene (MMA/BMA/St = 80/10/10, weight ratio). In the paper castor oil (CO) was used as PU’s branch units, the damping properties affected by the branch units ratio (ρ) were studied. Mechanical tests showed the tensile strength of the IPNs was improved after increasing the ρ value and PA content. The thermal stability was improved by incorporating heterocyclic imide rings into the PU molecular chains using isocyanate reacting with pyromellitic dianhydride (PMDA). It was found that the IPN composition with ρ value = 0.2 and PU/PA = 60:40 would be useful as structural damping materials, having tanδ values higher than 0.3 for a temperature range of 102°C (5.0-106.9°C).

Preparation and properties of polyurethane‐modified epoxy cured in different simulated gravity environments

ABSTRACTGreat attention has been paid to the composites with interpenetrating polymer networks (IPNs) because of their special performance. However, the influence of sedimentation and convection from different gravity environments on the formation of IPNs and the properties of IPNs blends has received little attention. To understand their influence, environments with different gravity accelerations of 0g, 1g, and 2g were simulated with a superconducting magnet, and tests, including differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), coefficient of thermal expansion (CTE), scanning electron microscopy, and three‐point bending, of the IPNs blends cured in different gravity environments were conducted and analyzed. Fourier transform infrared spectroscopy, DSC, and DMA proved the formation of IPNs during the reaction between the polyurethane prepolymer (PUP) and epoxy resin (E51). The curves of DSC also certified the differences in the curing degree between the different parts along the direction of gravity of a sample. With the increase of mass fraction of PUP, the change trends of the storage modulus presented a linear decrease when samples cured in microgravity environment, but presented a parabolic trend when samples were cured in terrestrial environment. The damping properties of samples cured in simulated microgravity environments are better than those cured in terrestrial environment. With the increase in the simulated acceleration of gravity, the diameter of dispersed phase in a sea‐island structure increased, but their number decreased and the bending stress and CTE of the IPN blends all decreased. These results show the formation of IPNs was affected by different gravity values, and the thermal and mechanical properties of the IPN composites were influenced by the changed IPN components. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 42063.