Preparation and characterization of a semi‐interpenetrating network gel polymer electrolyte

Poly(PEG200 maleate) was synthesized as a new type crosslinkable prepolymer and the semi‐interpenetrating polymer network (semi‐IPN) gel electrolytes were prepared by means of thermal polymerization. Their intrinsic properties were characterized by FTIR spectroscopy, differential scanning calorimetry (DSC), X‐ray diffractions (XRD), scanning electron microscopy, alternating current impedance (AC impedance), and linear sweep voltammetry. The prepared polymer hosts are transparent and have good mechanical properties. The results of DSC and XRD confirm that the prepared hosts are in amorphous state and they can hold enough liquid electrolytes, which is favorable for Li⁺ ions to transport via both the absorbed liquid electrolyte and the gel of the entire systems. The semi‐IPN gel electrolytes exhibit high ionic conductivity on the order of 10^?3 S cm^?1. Their electrochemical stability up to +4.6 V against Li⁺/Li also makes them potential candidates for application as polymer electrolytes in devices. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2008     

Ionomer interpenetrating polymer networks from polyurethane anionomers and polyurethane isocyanurate

Two-component interpenetrating polymer network (IPN) systems composed from polyurethane isocyanurate and polyurethane anionomer were prepared by simultaneous polymerization and crosslinking in solution. Specific attractive forces that occurred among various networks helped to make them compatible and led to the formation of true homogeneous topologically interpenetrating polymer networks. These ionomer IPNs were characterized by means of stress-strain properties, hardness, thermogravimetric analysis, density and conductivity. The morphology of the IPNs was studied by thermomechanical analysis and dynamic mechanical analysis.     

Interpenetrating polymer network of poly(vinyl chloride) and polymethacrylates

A curable polymeric composite was prepared using equal weights of poly(vinyl chloride) (PVC), reactive polyfunctional methacrylate monomers, and inorganic fillers. Peroxide initiated in situ polymerization of the polyfunctional methacrylate monomers in the PVC matrix produced an interpenetrating polymer network (IPN) structure. The polymerization kinetics and the degree of polymerization were investigated using differential scanning calorimetry (DSC), carbon-13 nuclear magnetic resonance (¹³C NMR), and solvent extraction. All measurements indicated that during polymerization, the PVC is either crosslinked by or grafted onto the methacrylate three-dimensional network structure. The rheological properties of the composite were measured before curing using a Rheometrics mechanical spectrometer and found to exhibit mainly viscous behavior and diminished elasticity. The PVC and the methacrylate monomers form a two-phase system when mixed at room temperature. However, when heated to 100°C the PVC dissolves in the monomers and forms a one-phase optically clear blend with a single glass transition temperature. In the presence of peroxide, the one-phase blend is stable and does not separate out upon cooling and storing at room temperature.     

Preparation of SBS/poly(styrene–methyl methacrylate) thermoplastic interpenetrating polymer network

SBS as polymer I, poly(styrene–methyl methacrylate) polymerized by atom transfer radical polymerization as polymer II, and a thermoplastic interpenetrating polymer network of SBS/poly(styrene–methyl methacrylate) were prepared by the sequential method. The effects of the polymerization temperature, the composition of the catalyst, the ratio of the monomers studied, and the kinetics at 90°C were also investigated. It was shown that when polymerization was initiated by a BPO/CuCl/bpy (BPO:CuCl:bpy = 1:1:3) system at 90°C, the mass averaged molecular weight of the poly(styrene–methyl methacrylate) increased with monomer conversion, and the polydispersities were kept very low. Fourier transform infrared spectroscopy and gel permeation chromatogram showed that poly(styrene–methyl methacrylate) with low polydispersities had been synthesized. Thus, a thermoplastic interpenetrating polymer network comprised of both narrow molecular‐weight‐distribution components was successfully prepared. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 2007–2011, 2003     

Photocrosslinked polymer and interpenetrating polymer network for nonlinear optics

Two photocrosslinkable NLO polymers of poly(glycidyl methacrylate) substituted with 4‐nitro‐4′‐hydroxyl stilbene (PGMAS) and acryloyl‐functionalized epoxy‐based polymer (PENAA) carrying 4‐nitroaniline moieties were synthesized and characterized. By using the sulfonium salt cationic photoinitiator BDS · 2PF₆ which can induce cationic or/and radical polymerization, the photocrosslinking of PGMAS and the interpenetrating polymer network (IPN) formed by the photocrosslinking of PGMAS and PENAA simultaneously were reported. The poled and photocrosslinked polymer films and IPN films exhibit relatively stable second‐order nonlinear optical activity. The influence of stilbene isomerization in PGMAS films with different crosslink densities on the SHG stability was also investigated. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1081–1087, 1999     

A robust and coarse surface mesh modified by interpenetrating polymer network hydrogel for oil‐water separation

A robust and coarse surface mesh was fabricated by introducing a hydrogel coating with interpenetrating polymer network (IPN) structure on stainless steel mesh. The IPN hydrogel was prepared by crosslinking polymerization of acrylic acid (AA) followed by condensation reaction of polyvinyl alcohol (PVA) and glutaraldehyde (GA) at room temperature. As a result, the roughness of modified mesh was enhanced obviously and oil droplet underwater showed a larger contact angle. The hydrogel‐coated surface showed an underwater superoleophobicity with an oil contact angle of 153.92 ± 1.08^°. Besides, stable wettability was observed. The mesh can selectively separate oil from water with a high separation efficiency of above 99.8%. This work provides a facile method to strengthen the coating and enhance the efficiency of oil‐water separation. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41949.     

Elastomeric domain-type interpenetrating polymer networks

Elastomeric latex interpenetrating polymer networks (IPNs) can result from a two-stage emulsion polymerization procedure in which styrene is polymerized and cross-linked on a lightly cross-linked polyacrylate (PA) seed latex in a ratio of 75 : 25 PA-PS. The multiphase nature of these IPNs is indicated by two distinct T_gs and is confirmed by cold-stage transmission electron microscopy and by the unique mechanical and rheological properties that are intimately related to the material's structure. PS microdomains reinforce the elastomeric PA, yielding a significant modulus, and interparticle PS physical ties yield a significant ultimate tensile strength. The elastomeric latex IPN's dual thermoset-thermoplastic nature is revealed in a stick, slip, roll flow mechanism of the cross-linked submicrometer particles, which can be injection molded as a thermoplastic. The relationships among the polymerization procedure, the structure, and the physical properties are characterized by the examination of several different materials using a variety of analytic techniques.     

Interpenetrating polymer networks from castor oil based polyurethane and poly(methyl methacrylate), III

Liquid prepolyurethanes (PPU) were obtained from castor oil and toluene-2,4-diisocyanate under different experimental conditions varying NCO/OH ratio. All these prepolyurethanes were subsequently interpenetrating with poly(methyl methacrylate) made by radical polymerization initiated with benzoyl peroxide. The novel PPU/PMMA interpenetrating polymer networks were obtained as though films by transfer moulding. They were characterized by thermal studies (DSC and TGA) and mechanical properties viz., tensile strength, modulus of elasticity, and percent elongation at break. The morphological behaviour was analyzed by scanning electron microscopy.     

Latex interpenetrating polymer networks based on acrylic polymers. III. Synthesis variations

Two latex interpenetrating polymer networks, one from a supposedly compatible pair and the other from an incompatible pair of polymers, were prepared by two-stage emulsion polymerization. The synthesis conditions in each case were varied by altering the ratio of the glassy polymer to the rubbery polymer and also by reversing the order of synthesis. Fabricated samples of these latex interpenetrating polymer networks were subjected to hardness, stress-strain, and dynamic mechanical measurements. Hardness and stress-strain measurements showed that, although the second formed polymer dominated the final mechanical properties, the compatibilities of the polymer pairs played an important role. Dynamic mechanical analysis for the inverse systems showed evidence of enhanced mixing.     

Interpenetrating polymer networks based on polyurethane and organic-inorganic copolymer

The investigation of the features of the formation of interpenetrating polymer networks (IPNs) based on cross-linked polyurethane and organic-inorganic copolymer (OIC) based on hydroxyethyl methacrylate (HEMA) and titanium isopropoxide (Ti(OPrⁱ)₄) was carried out using the IR spectroscopy method. It has been demonstrated that during the synthesis of organic-inorganic IPNs (OI IPNs), three-dimensional cross-linked structures with the inclusion of (-TiO₂-) fragments in the polymer chain of poly(hydroxyethyl methacrylate) are formed. The examinations of the viscoelastic properties and thermal stability of organic-inorganic IPNs by dynamic mechanical (DMA) and thermogravimetric analysis (TGA) showed that the value of M _c decreases with an increase in the content of (-TiO₂-) fragments in OI IPN; in addition, the thermal stability of the obtained hybrid OI IPNs increases significantly compared to the parent systems.     

Synthesis and properties of novel organic thiolane polymer as cathode material for rechargeable lithium batteries

A novel thiolane polymer, poly[1,2,4,5-tetrakis(propylthio)benzene] (PTPB), was synthesized by facile oxidative-coupling polymerization, characterized by FT-IR, XPS, XRD, TGA and EA, and tested as cathode active material in rechargeable lithium batteries. The FT-IR, XPS and elemental analysis confirm the occurrence of polymerization and show the existence of C–S–C bonds. The results show that the thiolane polymer has electrochemical activity as cathode material in lithium batteries and thioether bonds may be the centers of the electrode reaction. A maximum specific capacity of 200 mAh g⁻¹ was obtained and this agrees roughly with the theoretical prediction. In addition, high voltage efficiency was obtained first time from sulfide polymer.     

High polymer/surfactant ratio in the seeded semicontinuous heterogeneous polymerization of vinyl acetate

Vinyl acetate (VAc) was polymerized by a seeded semicontinuous heterogeneous process. Stable latexes with a polymer/surfactant weight ratio of 65 were obtained, which is comparable with the highest value reported in the literature for emulsion polymerization but with the advantage of obtaining smaller particles (average diameter, D_p = 53 nm) which are similar to those obtained by microemulsion polymerization. The surfactant (sodium dodecylsulfate, SDS) concentration used in the recipe (0.32 wt%) is much lower than those typically used in microemulsion polymerization. Although molar masses increased during the continuous monomer addition period, they were small at the end of the reaction (M_n = 69 × 10³ g·mol^–1) and this was attributed to bimolecular termination inside the particles. The values of polymerization rate (R_p) and monomer addition rate (F_m) were nearly the same, indicating that polymerization was performed under monomer starved conditions. POLYM. ENG. SCI., 2013. © 2013 Society of Plastics Engineers     

Interpenetrating polymer networks of bismaleimide and polyether polyurethane–crosslinked epoxy

In this work, we prepared the interpenetrating polymer networks of bismaleimide and polyether-type polyurethane(polyoxypropylene)–crosslinked epoxy (BMI/PU(PPG)–EP IPNs) by employing the simultaneous bulk polymerization technique. The polyurethane (PU)–crosslinked epoxy was identified via infrared (IR) spectra analysis. Also investigated herein were the mechanical properties, including tensile strength, Izod impact strength, and fracture energy (G_IC) of the IPNs with various BMI contents in PU–crosslinked epoxy matrix. In addition, differential scanning calorimetry (DSC) analysis and the thermogravimetric analysis (TGA) were performed to examine the thermal properties of the BMI/PU(PPG)–EP IPNs. In addition, morphology and dynamic mechanical analysis (DMA) of the BMI/PU(PPG)–EP IPNs were also studied. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2635–2645, 1998     

Poly(vinyl acetate)/polyacrylate semi‐interpenetrating polymer networks,part 1: Synthesis and polymerization kinetics

Bulk photopolymerization was used to synthesize a series of semi‐interpenetrating polymer network (s‐IPN) based on linear poly(vinyl acetate) and crosslinked N‐butyl acrylate/1,6‐hexandiol diacrylate (HDDA) copolymer. Different formulations were used by varying the monoacrylate/diacrylate molar ratio and the linear polymer concentration. The polymerization kinetics was studied as a function of the s‐IPN composition by FTIR spectroscopy. It was observed that the reaction rate increases by increasing the linear polymer amount. This effect is much more pronounced in the reaction mixtures with a higher diacrylate concentration, playing a key role the restricted mobility of the macroradicals involved in the bimolecular termination. The maximum conversion increases regularly with linear polymer concentration in the blend and resulted to be very high, ranging from 95 to 98%. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Photo-oxidative coupling polymerization of methoxy acetonitrile and thermal behavior of the polymer obtained

Photo-oxidative coupling polymerization of methoxy acetonitrile was carried out by using organic peroxide as an oxidizing agent under UV light irradiation at ambient temperature. The acetonitrile gave a homopolymer with a molecular weight of about 1000-1600 in moderate yield. ¹H-NMR and ESR spectra demonstrated the production of the polymer with the structure of 1,1-disubstituted polymethylene through a methoxycyanomethyl radical intermediate. It was also found that the polymer easily produced unpaired electrons in the structure only by heating and it initiated the polymerization of methyl methacrylate above 70°C. In addition, the acetonitrile also afforded a copolymer with diphenylmethane by the coupling polymerization.     

Recent studies on interpenetrating polymer networks

Recent 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 T_gs 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.     

Synthesis and characterization of four-armed star mesogen-jacketed liquid crystal polymer

The synthesis of four-armed star mesogen-jacketed liquid crystal polymer was achieved by atom transfer radical polymerization in chlorobenzene solution using pentaerythritol terakis(2-bromoisobutyrate) (PT-Br) as an initiator and CuBr/sparteine complex as a catalyst. The results show that the number average molecular weigh is creased linearly vs. monomer conversion, and that the polydispersities were quite narrow (<1.19), which is the character of controlled polymerization. The structure was experimentally confirmed by ¹H NMR. The liquid-crystalline behavior of the four-armed star polymer was studied using DSC and POM. Only the polymer with a M_n,GPC beyond 3.68×10⁴ g/mol formed a liquid crystalline phase which was quite stable with a high clearing point.     

Acronal-polymethyl acrylate interpenetrating polymer networks

Four interpenetrating polymer networks were prepared by swelling crosslinked Acronal (a copolymer of styrene and butyl acrylate) with methyl acrylate plus crosslinking agent and then polymerizing the methyl acrylate in situ. Certain properties of the constituent network materials, plus the interpenetrating polymer networks which contained 70, 50, 35 and 25% by weight of polymethyl acrylate, were investigated. Electron microscopy showed the interpenetrating polymer networks to be two-phase materials with the polymethyl acrylate domain size increasing with increasing polymethyl acrylate content. Longitudinal sonic velocity measurements indicate that at around 50% by weight of polymethyl acrylate both phases become continuous while dynamic mechanical spectroscopy leads to the view that the constituent networks were not extensively mixed.     

Latex interpenetrating polymer networks based on polyacrylates and polystyrene. I. Synthetic variations

Two different acrylic copolymeric seeds (with 0 and 6% methacrylic acid), having very high variation in the hydrophilicity, were used to develop latex interpenetrating polymer networks (LIPNs) with polystyrene as polymer II, to study the effect of the mode of monomer II addition such as continuous monomer addition and absorption method/swelling the seed with monomer II, followed by polymerization. Linear combination of the two polymers were also prepared to understand the above effects on the final properties such as the glass transition temperature, hardness, and tensile strength of the different samples prepared. The results showed that the addition of styrene monomer by the absorption method and the increase in hydrophilicity of the seed improved the mixing of the two polymers, thus resulting in producing LIPNs possessing broad glass transition with high strength and hardness. © 1996 John Wiley & Sons, Inc.     

Radical/Addition polymerization silicone hydrogels with simultaneous interpenetrating hydrophilic/hydrophobic networks

Transparent silicone hydrogels with interpenetrating hydrophilic/hydrophobic networks were simultaneously synthesized on the basis of the radical polymerization of the methacrylic monomer of 3‐methacryloxypropyl tris(trimethylsiloxy) silane (TRIS)/N,N‐dimethylacrylamide (DMA) and the addition polymerization of hydroxyl‐grafted polysiloxane (HPSO)/isophorone diisocyanate. The curing temperature was set at 80°C by a differential scanning calorimetry study. The polymerization process was studied by in situ Fourier transform infrared spectroscopy. The results indicate that the curing time was about 4.5 min, and the addition polymerization had a faster rate than radical polymerization. Then, the radical polymerization rate increased rapidly, and this led to instant curing. The interpenetrating polymer network (IPN) silicone hydrogels were characterized by swelling kinetics and dynamic mechanical thermal analysis. The results show that all of the hydrogels reached swelling equilibrium at about 4 h in water, and the IPN silicone hydrogels with a hydrophobic network of HPSO indicated a slower water transport than that of the copolymerization hydrogel of DMA and TRIS. The hydrophobic network was finely dispersed in the hydrophilic network, and the increasing hydrophobic network of HPSO decreased the glass‐transition temperature of the IPN silicone hydrogels. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41399.