Types Of Interpenetrating Polymer Networks Research Articles

새로운 Silane 모노머와 IPN 중합체의 경화 연구

Interpenetrating polymer networks (IPNs) that have silane resins as one of their components are industrially important due to their physical and chemical properties. The current study included preparation and characterization of two types of unsaturated silane monomers in order to prepare new types of IPNs with unsaturated polyesters (palatal). These monomers were characterized with Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (<SUP>1</SUP>H NMR), and their molecular weights were determined by cryoscopy technique. The curing properties of the silane monomers and the IPNs were observed by differential scanning calorimetry (DSC), and several of thermal curing functions were determined, such as the initial curing temperature, optimum curing temperature, curing energy, activation energy and rate of curing. There was a significant decrease in the initial and maximum curing temperatures compared with the unsaturated polyester resin (palatal) due to the decrease in the activation energy from 105.4 to 77.3 ºC when the allyoxy silane monomer percentage was shifted from 5 to 20%. Meanwhile, the activation energy for the IPNs based on α-methyl-butenoxy silane decreased from 96.8 to 55.8 kJ/mol.

Enhanced adsorption of methyl violet and congo red by using semi and full IPN of polymethacrylic acid and chitosan

Semi and full interpenetrating polymer network (IPN) type hydrogels were prepared by free radical in situ polymerization of methacrylic acid in presence of chitosan using N,N′-methylene-bis-acrylamide (MBA) and glutaraldehyde (for full IPN) as crosslinker. Several semi and full IPN type hydrogels were prepared by varying initiator and crosslinker concentration and also monomer to chitosan mass ratio. These hydrogels were characterized and used for removal of methyl violet and congo red dye from water. Isotherms and kinetics of dye adsorption were also evaluated.

Synthesis and characterization of sequential interpenetrating polymer networks of polyurethane acrylate and polybenzoxazine

High-performance ultraviolet (UV) curable polyurethane acrylate (PUA) coating alloyed with thermally curable polybenzoxazine (PBA) is developed. The hybrid polymer networks of PUA and PBA-a were prepared by sequential cure methods, i.e., UV cure of the PUA followed by thermal cure of the PBA fraction. The effects of sequential cure were investigated in terms of mechanical, thermal, and physical properties of the resulting polymer alloys. The fully cured PUA/PBA-a alloy films showed only single glass transition temperature (Tg) suggesting high compatibility between the two polymer networks, possibly of an interpenetrating polymer network type. The storage modulus in a glassy state and Tg of PUA/PBA-a alloys were found to substantially increase with increasing PBA-a content. Furthermore, degradation temperature at 10% weight loss of the PUA/PBA-a alloy films was relatively high whereas the char yield at 800°C was found to increase with a PBA-a component. Hardness was enhanced, whereas water absorption and water vapor permeation rate of the alloy were suppressed by the incorporation of the PBA-a into the polymer alloys. As a consequence, the properties of UV curable PUA networks can be positively tailored and enhanced by forming hybrid network with PBA-a. POLYM. ENG. SCI., 54:1151–1161, 2014. © 2013 Society of Plastics Engineers

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

AbstractSemi‐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

Studies on engineering properties of PVC–PMMA semi‐interpenetrating polymer networks

AbstractSemi1 and semi2 interpenetrating polymer networks (IPNs) of PVC and in situ formed PMMA have been synthesized using diallyl phthalate and ethylene glycol dimethacrylate as the crosslinkers of PVC and PMMA, respectively. These two types of IPNs have been compared w.r.t 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 semi1 IPNs displayed a decrease in their mechanical parameters and the physical properties as well, while in contrast, the semi2 IPNs exhibited a marginal increase in the corresponding values after an initial drop upto about 15% of crosslinked PMMA incorporation when compared to the crosslinked PVC in the case of semi1 IPN and linear PVC in the case of semi2 IPN. The various samples of semi1 and semi2 IPNs showed a two‐stage degradation typical of PVC, while confirming the increased stability with the samples having higher percentages of PMMA. The influence of crosslinking of the major matrix in semi1 IPN was almost counterbalanced by the influence of crosslinking in the dispersed PMMA phase in the case of semi2 IPN. The softening characteristics as detected by the extent of penetration of the probe, as has been detected by thermomechanical analysis, are in conformity with their mechanicals. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1725–1735, 2005

Engineering properties of Novolac resin‐PMMA{poly(methyl methacrylate)} IPN system

AbstractFull and semi interpenetrating polymer networks (IPNs) based on phenol‐formaldehyde resin (Novolac) and poly(methyl methacrylate) have been made by in situ sequential technique of IPN formation. These systems of different compositions were characterized with respect to their mechanical properties, such as, ultimate tensile strength (UTS), percentage elongation at break, modulus, and toughness. Thermal properties were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Extent of phase mixing of the two polymers was envisaged from the micrographs obtained by polarizing light microscopy (PLM). The effects of variation of the blend ratios on the above‐mentioned properties were examined. There was a decreasing trend of modulus and UTS with consequent increases in elongation at break and toughness for both types of IPNs with increase in proportions of PMMA. Lowering of glass transition temperatures (with respect to pure crosslinked Novolac resin) of the IPNs with increasing proportions of PMMA was observed, indicating a plasticizing influence of PMMA on the rigid and brittle matrix of phenolic resin. The TGA thermograms exhibit lowering in thermal stability of the IPNs with respect to pure phenolic resin in the regions of higher temperatures. With increase in proportion of PMMA the onset of degradation of the IPNs is shifted towards lower temperature zone. The surface morphology as revealed by PLM indicates distribution of discrete domains of PMMA in the phenolic resin matrix. The two phase interfaces are quite sharp at higher concentrations of PMMA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2764–2774, 2004

Adhesives made from interpenetrating polymer networks for bonding rusted iron without pretreatment

Adhesives made from two types of room-temperature-cured interpenetrating polymer network (IPN) based on (1) castor oil polyurethane (PU)/vinyl or acrylic polymer and (2) PU/(unsaturated polyester and vinyl or acrylic polymer) were studied. The effects of NCO/OH molar ratio, PU content, type of vinyl or acrylic monomer and weight ratio of monomer/polyester on the adhesive properties of IPNs between rusted iron plates were investigated. The results showed that, for the first type of IPN, the lap-shear strength of the IPN between rusted iron plates exhibited a maximum value at 60–80% PU content and increased with NCO/OH molar ratio. For different monomers, the lap-shear strength of the IPNs decreased with decreasing glass transition temperature ( T g ) of the vinyl or acrylic polymer. For the second type of IPN, acrylonitrile seemed to be the best monomer. Optimum lap-shear strength occurred at about 88wt% acrylonitrile content in the acrylonitrile/(polyester+monomer).

Natural rubber-poly(methyl methacrylate) interpenetrating polymer networks—morphology and mechanical properties

Interpenetrating polymer networks (IPNs) were prepared by the sequential mode of synthesis using natural rubber and poly(methyl methacrylate) as the elastomer and plastomer components respectively. Two types of IPNs, viz. full and semi, were prepared and characterized by measurements of tensile strength, elongation at break, tensile modulus, tear strength and toughness and by scanning electron microscopy. Dicumyl peroxide and divinyl benzene were used as the crosslinker of natural rubber and comonomer/crosslinker for methyl methacrylate monomer, with benzoyl peroxide as the polymerization initiator. Effects of changes of blend ratio and extent of crosslinking of both plastomer and elastomer on the properties were examined. Full IPNs were characterized by higher tensile strength, modulus, tear strength and finer phase distribution than the corresponding semi-IPNs, but the latter exhibited higher elongation at break and toughness than full IPNs.

Recent studies on interpenetrating polymer networks

AbstractRecent investigations on interpenetrating polymer networks (IPNs) have included two component IPNs from polyurethanes and poly(methacrylates) and two component IPNs from polyurethanes and epoxies. All the IPNs were prepared by the simultaneous polymerization technique (SIN‐IPNs). Two types of IPNs, polyurethane‐poly(methyl methacrylate) (PU/PMMA) and polyurethane‐poly(methyl methacrylate‐methacrylic acid) (PU/PMMA‐MAA) were prepared. Improved phase miscibility and decreasing extent of phase separation was observed in both types of IPNs with increasing the NCO/OH ratio, decreasing molecular weight of the polyol in the PU and introduction of charge groups. A comparison was made between full‐IPNs, pseudo‐IPNs, graft copolymers and related homopolymers from polyurethanes and epoxies. Increased compatibility in full‐IPNs and graft copolymers was observed by means of DSC, SEM and was also further substantiated by a shift toward single Tgs as determined by dynamic mechanical spectroscopy. The introduction of opposite charge groups in two‐component IPNs from polyurethanes and epoxies led to improved compatibility (no phase separation) and enhanced mechanical properties.

Nomenclature of Interpenetrating Polymer Networks

A nomenclature scheme for various types of interpenetrating polymer networks (IPN) based on morphology, topology, and method of synthesis is presented. In this scheme, IPN is the generic name of all polyblends of this type, regardless of their origin, as opposed to Sperling's recent classification of polyblends and graft copolymers, (Polymer Preprints, 14, (2), August, 1973), in which the various types of IPN's are given separate classifications under the generic heading of polyblends.