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The new magnetic and heat-resistant polyamide ether (PAE)/graphene oxide (GO) nanocomposites were prepared by blending PAE with modified GO. Furthermore, a novel PAE containing flexible ether, methyl, and triphenylmethane moiety in the main chain of PAE was prepared by direct polycondensation reaction of a diamine and 4,4′-(butane-1,4-diylbis(oxy))dibenzoic acid (9). The prepared PAE was characterized using various techniques. The obtained PAEs were readily soluble in various aprotic polar solvents at room temperature. The incorporation of bulky aryl pendant groups and flexible ether linkage into the backbones of polyamide may provide beneficial effects for solubility, as this approach produces a separate chain of the polymer, which makes weaker of hydrogen bonds. GO, which synthesized by the Hummer method, was modified with tetraethylenepentamine (GO-TEPA) and sequentially magnetized with Fe3O4 nanoparticles via chemical coprecipitation (GO-TEPA@Fe3O4). The PAE/GO/TEPA@Fe3O4 nanocomposite films, PAE/GO-TEPA@Fe3O4, were also synthesized as a heat-resistant and superparamagnetic nanocomposites, which were characterized using different analyses, such as field emission scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray, thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), and Fourier transform infrared techniques. TGA of nanocomposites exhibit higher degradation temperature than that of neat PAE, which is an indication of high levels of interfacial interaction and dispersion.

Laboratory studies show that bisphenol A (BPA) leaches from bisphenol A-glycidyl methacrylate (bisGMA)-based dental materials. We aimed to quantify the extent to which children are exposed to BPA from dental treatment with bisGMA materials, by amount of treatment and type of sedation. We hypothesized that posttreatment urinary BPA (uBPA) concentrations would be higher among patients with more surfaces treated with bisGMA-based materials and among patients receiving general anesthesia compared with pretreatment concentrations. We conducted a prospective cohort study in 211 children, 4 to 12 y old, who had no prior resin-based dental treatment. We measured uBPA concentrations twice before treatment and at 2 d and 1, 4, and 16 wk posttreatment. We abstracted treatment data (surfaces treated) from the chart. We generated descriptive statistics and compared pre- and posttreatment uBPA concentrations using generalized estimating equations. Participants were 51% female, 46% non-White, and 74% publicly insured. The median age was 6 y. The mean number of tooth surfaces exposed to BisGMA materials (composites/sealants) was 7.5 (SD 5.3). Overall, uBPA concentrations were 86% higher (95% confidence interval [CI] 42% to 143%, P < 0.001) at 2 d posttreatment compared with pretreatment concentrations. The uBPA concentrations 2 d posttreatment versus pretreatment tended to be higher (112%, 95% CI 53% to 194%) among those receiving treatment on >4 surfaces than those receiving treatment on ≤4 surfaces (50%, 95% CI −2% to 130%). Two days after treatment, uBPA was significantly higher than pretreatment concentrations in children receiving nitrous oxide but not in those receiving general anesthesia. Among all findings, uBPA concentrations returned to baseline by 4 wk. Children experience short-term increases in BPA from dental treatment. The impact of relatively high, short-term BPA exposure on child health is unknown. Given the widespread use of BisGMA-based dental materials and that chronic low-dose BPA exposure may adversely affect child health, strategies that minimize BPA exposure could potentially improve child health.

In this study, bamboo and glass fibers were successfully added into bisphenol A–aniline-based benzoxazine resin by hot pressing method. The effect of water absorption on the mechanical properties of the neat benzoxazine and its composites was studied. The composites prepared in this study has been proved to exhibit better water resistance than some conventional natural fiber/polymer composites due to good hydrophobicity of the benzoxazine matrix. From the mechanical tests, the tensile performance of both neat benzoxazine and the composites degraded seriously after prolonged immersion in water. However, neat benzoxazine and the composites maintained relatively higher residual flexural properties (residual mechanical properties refer to the ratio of strength and modulus of the saturated samples to that of the nonaged samples) after 20 days of water immersion. The effect of water molecules on the fracture surface morphologies of the composites was studied using a scanning electron microscope (SEM). The SEM images showed that the interfacial bonding between fibers and the matrix degraded seriously due to the attack of water.

4-(4-Diphenylphosphino)phenyl-2,6-bis(4-hydroxyphenyl)pyridine, as a new bisphenol monomer, was prepared from 4-(diphenylphosphino)benzaldehyde and 4-hydroxyacetophenone and used in the preparation of several aromatic poly(ether ketone)s (PEKs) containing 2,6-diphenylpyridyl units and diphenylphosphinophenyl pendant groups via a nucleophilic aromatic substitution polycondensation with difluorinated aromatic ketones. The polycondensation proceeded quantitatively in tetramethylene sulfone in the presence of anhydrous potassium carbonate and afforded the polymers with high molecular weights. The resulting PEKs are amorphous and exhibit high glass transition temperatures of 209–255°C and 5% weight loss temperatures of 536–554°C with char yields of 57–62% at 800°C in nitrogen. Their high char yields and good limited oxygen index values ranging from 39 to 43 indicated these polymers exhibited good thermal stability and flame-retardant property. All new PEKs were soluble in common organic solvents such as N-methyl-2-pyrrolidone, N,N-dimethylacetamide, and chloroform and could form tough, flexible, and strong films with tensile strengths of 74.6–86.8 MPa, tensile moduli of 2.9–3.6 GPa, and elongations at break of 5–9%.

The properties of heat stabilisers Bisphenol-5 [4,4′-bis(2,6-di- tert-butylphenol)] and Vulcanox BKF [2,2-methylene-bis(4-methyl-6- tert-butylphenol)] and their efficiency in stabilising nitrile butadiene rubbers (SKN-1865 and SKN-2665) were investigated. The efficiency of the antioxidants was assessed from the thermooxidative ageing of the rubbers at 150°C over the course of 1 and 3 h. The Mooney viscosity and solubility of specimens with Bisphenol-5 change less during oxidation than those of specimens with Vulcanox BKF. The good stability of the Bisphenol-5 dispersion after additional treatment in a ball mill for 12 h was shown. Stability was assessed from the sedimentation rate of antioxidant particles and from the ratio of sediment to dispersion volume. The vulcanisation time and physicomechanical properties of compounds based on rubbers containing Bisphenol-5 and Vulcanox BKF were compared. The recommended content of Bisphenol-5 in SKN-1865 rubber is 0.23 parts, and in SKN-2665 rubber 0.3 parts. Bisphenol 5 can be recommended as a replacement for imported Vulcanox BKF for the stabilisation of nitrile butadiene rubbers.

A series of new polyarylates bearing cardo xanthene groups were synthesized by phase-transfer-catalyzed interfacial polycondensation of 9,9-bis[4-(4-chloroformylphenoxy)phenyl]xanthene with various bisphenols containing the isopropylidene, hexafluoroisopropylidene, 1-phenylethylidene, diphenylmethane, cyclohexane, and xanthene structures. High-molecular-weight polyarylates with number-average molecular weight and polydispersity index in the range of 30,100–35,300 and 1.82–2.17, respectively, exhibited high glass transition temperatures ranged from 226°C to 261°C, and their 10% weight loss temperatures were in the range of 421–452°C with char yields above 45% at 700°C in nitrogen. All the polyarylates were amorphous and readily soluble in organic solvents such as dichloromethane, chloroform, tetrahydrofuran, meta-cresol, pyridine, N,N-dimethylformamide, N,N-dimethylacetamide, and 1-methyl-2-pyrrolidinone at room temperature and could be cast into tough, transparent, and flexible films with tensile strengths of 85.6–108.3 MPa, elongations at break of 2–3%, and tensile moduli of 7–9 GPa.

Two kinds of polyarylates with diphenylamine-fluorene units were synthesized from the bisphenol monomer “ N, N-di(4-hydroxyphenyl)-2-amino-9,9-dimethylfluorene” with two different benzenedicarbonyl chlorides. These polyarylates were highly soluble in N, N-dimethylacetamide, tetrahydrofuran, and chloroform and could be easily solution-cast into transparent films. Both of the polyarylates exhibited a couple of reversible redox with half-wave potentials in the range of 0.87–0.90 V. During the electrochromic process, the color of the film changed from colorless (neutral state) to grey green (oxidation state) with a high coloration efficiency of 242 cm2 C−1. Compared with the polyarylates prepared from terephthaloyl chloride, the polyarylates prepared from isophthaloyl chloride exhibited enhanced fluorescence because of the reduced charge-transfer effect. Furthermore, its fluorescence could be reversibly switched under the applied potentials.

Electroactive shape memory composites were synthesized using polybutadiene epoxy and bisphenol A-type cyanate ester filled with 2 wt% carbon fiber; 3 wt% carbon fiber; 4 wt% carbon fiber; 4 wt% carbon black; 4 wt% carbon black and 0.3 wt% carbon fiber; 4 wt% carbon black and 0.5 wt% carbon fiber; 4 wt% carbon black and 0.8 wt% carbon fiber. Mechanical, electrical performance, and electroactive shape memory behavior were systematically investigated by dynamic mechanical analysis and scanning electron microscopy. It is found that the volume resistivity sharply decreased due to excellent electrical conductivity and synergic effect of carbon black and carbon fiber, in turn resulting in good electroactive shape memory properties. The content of carbon fiber and applied voltage had significant influence on electroactive shape memory effect of the developed bisphenol A-type cyanate ester/polybutadiene epoxy/carbon black/carbon fiber composites. Shape recovery can be observed within a few seconds with carbon black content of 4 wt%, carbon fiber content of 0.5 wt%, and voltage of 60 V. Shape recovery time decreased with the increase content of carbon fiber and voltage.

Cyanate ester (CE) foams with different chemical structures were prepared using bisphenol A dicyanate ester (BADCy), bisphenol E dicyanate ester (BECy), and tetramethyl bisphenol F dicyanate ester (TBFDCy) as monomers, through a two-step process. Rheological tests were performed to investigate the optimal conditions for the preparation of these foams. The results of morphology by scanning electron microscopy showed that cells are in the form of nearly spherical shape in foams from TBFDCy and BADCy and oval in foam from BECy. The thermal properties of the three CE foams were studied by methods of dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and thermogravimetry/differential thermogravimetry analysis. The glass transition temperature ( Tg) obtained from DMA tests are 274, 264, and 241°C for the foams from TBFDCy, BADCy, and BECy, respectively, which are apparently higher than that tested by DSC method. The Tg, compressive properties, and thermal stabilities of the foams are improved after the introduction of the alkyl-substituent groups to the same aromatic ring of –OCN functionality, and the chemical structure–properties relationships are explained according to the monomer chemical structures.

Bisphenol A (BPA) is a low molecular weight chemical compound that has a deleterious effect on the endocrine system. It was used in plastics manufacturing with injurious effects on different body systems. Occupational exposure to low-level ionizing radiation (

Bisphenol-substituted spirocyclic phosphazene derivatives were synthesized in 85%–94% yields and analyzed for flame retardant application to cotton fabric using Limiting Oxygen Index, Fourier transform infrared thermogravimetric analysis, differential scanning calorimetry, microscale combustion calorimetry, thermogravimetric analysis, and scanning electron microscopy. The thermogravimetric analysis methods indicate a decomposition pathway consistent for phosphorus-nitrogen-containing compounds. Levoglucosan phosphorylation and carbonaceous char formation were observed. Limiting Oxygen Index testing of these compounds on cotton-based fabrics showed improved flame resistance compared to untreated fabrics.

Polyarylene ether nitrile (PEN) blends with different mass ratios of PEN bisphenol (BP) to PEN bisphenol A (BPA) were prepared by solution casting method. The morphological, rheological, thermal, dielectric, and mechanical properties of the resulted blends were systematically studied. Rheological studies show that the addition of PEN (BPA) could improve the flowability of blends except that of 90/10 (BP/BPA). Meanwhile, the crystallization degree of blends also decreases except that of 90/10 (BP/BPA). Mechanical measurement results indicate that the PEN blend (PEN (BP):PEN (BPA) of 90:10) possesses highest tensile strength of 119.7 MPa, increased by 28.6% than PEN blends (PEN(BP):PEN(BPA) of 50:50). Besides, the scanning electron microscopic images show that there exists phase separation in the PEN blends (PEN (BP):PEN (BPA) of 50:50), which is well consistent with the Cole–Cole plots obtained from rheological studies. Moreover, the phenomenon of phase separation will lead to interfacial polarization between the two different phases, which is a significant factor to induce the transformation of dielectric constant. Furthermore, all blends possess high thermal stability (initial decomposition temperature over 470°C) and high mechanical property (tensile strength over 93 MPa), suggesting that PEN blends (BP/BPA) have a good prospect of extension and application.

The compounds resorcinolbisbenzoxazine, quinolbisbenzoxazine, p-phenylene diaminebisbenzoxazine, and m-phenylenediaminebisbenzoxazine are prepared. The structural and thermal characterizations of the materials are done using Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H NMR) and 13C NMR, and differential scanning calorimetry. Both FTIR and NMR studies reveal the presence of oxazine rings in the synthesized monomers. The curing exotherm of these bisbenzoxazines is much influenced by the nature of the aromatic unit present in the chosen compound and also on the type of the benzoxazine unit in the system. Curing kinetics is performed using Flynn–Wall–Ozawa, Vyazovkin, and Friedman methods. The apparent activation energies ( Ea-C) for the thermal curing of the synthesized monomers varied and are dependent on the nature and the position of the functional groups present in the compound. The highest Ea-C values are noted for the compounds having the functionalizations being para oriented.

A new bisphenol, 9,9-bis(4-hydroxy-3-methylphenyl)xanthene, was synthesized via a one-pot, two-step synthetic procedure in good yield and used for polymerization with difluorinated aromatic ketones in tetramethylene sulfone in the presence of anhydrous potassium carbonate to form several aromatic poly(ether ketone)s (PEKs) with 9,9-diphenylxanthene moieties and methyl substituents. The newly synthesized high-molecular-weight PEKs having number-average molecular weights in the range of 20,500–25,600 g mol−1 with the polydispersity index ranging from 1.9 to 2.1 were all amorphous and showed high glass transition temperatures in the range of 194–229.8°C, and the temperatures at the 5% weight loss were in the range of 420–445°C with char yields above 60% at 600°C under nitrogen atmosphere. All new PEKs are soluble in polar aprotic solvents, such as N-methyl-2-pyrrolidone, N, N-dimethylacetamide, chloroform, pyridine, m-cresol, and tetrahydrofuran, and could form transparent, strong, and flexible films with tensile strengths of 66–74 MPa, Young’s moduli of 2.47–2.77 GPa, and elongations at break of 8–14%. In addition, these polymers had high transparency with an ultraviolet–visible absorption cutoff wavelength in the 352–356 nm range and low moisture absorption in the range of 0.41–0.56%.

Bisbenzoxazines were prepared by the condensation of the respective bisphenols bisphenol A (BA), indane bisphenol (IBP), and spirobiindane bisphenol (SBI) with paraformaldehyde and aniline. The apparent activation energies for the polymerization curing process ( Ea-C) and the degradation process ( Ea-D) were calculated using Flynn–Wall–Ozawa, Vyazovkin, and Friedman methods. The variation in Ea-C noted for the thermal curing of different bisbenzoxazines is attributed to the operation of different mechanisms for the curing process. The variation of the Ea-D for the degradation of spirobiindane benzoxazine polymerized at high temperature was different from the other materials investigated and is attributed to its complex structure. The volatile products obtained during the thermal degradation of the polymers were analyzed using thermogravimetric–Fourier transform infrared analyses. Aniline was found to be the major product and was released during the primary degradation. At higher temperatures, breakage of the isopropylidine, indane, and biindane structural entities were favored.

Received polycarbonate wastes from used optical discs chemically recycled to Bisphenol- A by using water as the solvent, Cloisite 30B nanoclay and sodium hydroxide as the support and catalyst, respectively at convenient, green and eco-friendly conditions. The performances of the support in Bisphenol- A recovery yield were examined in comparison with the unsupported as well as nano-SiO2 and nano-TiO2 supported reactions. The optimum condition by having 90% recovery yield was found at 90 min when the reaction performed at equal waste/solvent ratio, catalyst 1% and nanoclay 2%.

1,1-Bis(4-hydroxyphenyl)-1-(4-phenoxyphenyl)-1-phenylmethane (BHPPPPM), a new bisphenol monomer, was synthesized with 65% yield from 4-benzoyl diphenyl ether in a one-pot, two-step synthetic procedure. Four new poly(aryl ether ketone)s (PAEKs) bearing (4-phenoxyphenyl)triphenylmethane moieties were prepared from BHPPPPM with four difluorinated aromatic ketones via a nucleophilic substitution reaction. The polycondensation proceeded in tetramethylene sulfone in the presence of anhydrous potassium carbonate and afforded the new PAEKs in nearly quantitative yields with inherent viscosities of 0.60–0.78 dL g−1. The resulting PAEKs having number-average molecular weights in the range of 29,500–34,200 g mol−1 with the polydispersity index ranged from 1.94 to 2.01 are all amorphous and show high glass transition temperatures ranging from 174°C to 196°C, excellent thermal stability, and the temperatures at the 5% weight loss are over 500°C with char yields above 60% at 700°C under nitrogen atmosphere. These new PAEKs are all soluble in polar aprotic solvents such as N-methyl-2-pyrrolidone and N,N′-dimethylacetamide and could also be dissolved in chloroform and tetrahydrofuran. All the polymers formed transparent, strong, and flexible films with tensile strengths of 78–85 MPa, tensile moduli of 1.9–2.4 GPa, and elongations at break of 7–10%.

We report an efficient and novel method to functionalize graphene oxide nanosheets with hyperbranched polysiloxane and successfully compound them with dicyclopentadiene bisphenol dicyanate ester resin to prepare nanocomposites. Fourier transform infrared spectra were used to examine the surface functionalization of graphene oxide. The effects of functionalized graphene oxide on the mechanical, thermal, dielectric and water-resistant properties of dicyclopentadiene bisphenol dicyanate ester resin were investigated systematically. Results of differential scanning calorimetry (DSC) show that the addition of modified graphene oxide can facilitate the curing reaction of dicyclopentadiene bisphenol dicyanate ester. Compared with pure dicyclopentadiene bisphenol dicyanate ester resin, the impact and flexural strengths of the nanocomposite materials are improved markedly with up to 60% and 47% increasing magnitude, respectively. Meanwhile, the modified graphene oxide/dicyclopentadiene bisphenol dicyanate ester systems show lower and more stable dielectric constant and loss than pure dicyclopentadiene bisphenol dicyanate ester resin over the testing frequency from 10 to 60 MHz. In addition, the thermal stability and moisture resistance of modified graphene oxide/dicyclopentadiene bisphenol dicyanate ester nanocomposties are also superior to that of pure dicyclopentadiene bisphenol dicyanate ester resin.

Bisphenol A-based benzoxazine (BOZ) was blended with cyanate ester (CE) to improve the properties of cyanate resin. The effects of the content of BOZ on the mechanical property and dielectric property of the blends have been investigated. The results show that a suitable addition of BOZ can enhance the impact strength and flexural strength as well as reduce the dielectric constant and the dielectric loss of CE. The mechanical properties are significantly improved when the content of BOZ is 10 wt%, and the dynamic mechanical analysis reveals that the cross-link density of the blend is lower than pure CE. Scanning electron microscopy analysis shows distinct characteristics of ductile fracture of the blends. In addition, the dielectric constant and the dielectric loss of modified system decreases, compared with the curing CE. The optimal addition amount of BOZ resin is 15 wt% for the dielectric properties. The blend of a suitable addition of BOZ still remains a good thermal resistance. All these changes in properties are closely correlated to the copolymerization between BOZ and CE.

Polyurethanes (PURs) synthesized using hexamethylene diisocyanate (HDI) and polyethylene glycol with molecular weights of 400 g mol−1 and 600 g mol−1 (PUR 400 HDI and PUR 600 HDI) or polyoxypropylene diol (POPD) of molecular weights 1002 g mol−1 and 2002 g mol−1 (PUR 1002 HDI and PUR 2002 HDI) were used as modifiers for diglycidyl ether of bisphenol A. It was found that maximum improvement in impact strength and critical stress intensity factor ( KC) values was obtained for compositions containing 15% PUR 400 and 5% PUR 1002. Such improvement in the resistance to crack propagation due to PUR incorporation might be related with the soft segments of polyethylene glycol and POPD. The critical stress intensity factor ( KC) values increased from 1.7 MPa m1/2 (virgin epoxy) to 2.5 MPa m1/2 with the addition of 10% PUR 400. Fourier transform infrared spectra confirmed the formation of an interpenetrating polymer network structures with polymeric modifier. Scanning electron micrographs of epoxy resins (EPs) modified with PUR with longer chains (PUR 1002 and PUR 2002) exhibited a deformed leaf-like morphology with larger plastic deformation zones with the presence of microcracks. However, EP/PUR based on polyethylene glycol showed less deformed structure.

A new bisphenol monomer with pyridyl groups (compound 3) was synthesized via a two-step reaction. A series of functional poly(aryl ether ketone)s with pyridyl groups on the side chains (Py-PAEKs) were prepared by a nucleophilic substitution polycondensation of new bisphenol monomer, 2, 2-di(4-hydroxy phenyl)propane and easily available bisfluoro monomer at various molar ratios. Structures of compound 3 and Py-PAEKs were determined by means of 1H-NMR, IR spectra and elemental analysis. Thermal analysis of Py-PAEKs revealed that the glass transition temperature ( Tg) and the 5% weight loss temperature ( T5%) of these copolymers varied in the range of 147–176 °C and 432–330 °C, respectively, which showed strong chain rigidity and excellent thermal stability. Moreover, Py-PAEKs were soluble in some organic solvents under heating, which made them potentially used for self-assembly of rigid polymers.

A new nonfluorinated bisphenol monomer 2-(4-phenoxyphenyl)-1,4-diphenol was prepared via a four-step synthesis process. A series of poly(ether ether ketone) copolymers (6FPOP-PEEKs) were derived from 4,4′-difluorobenzophenone via a nucleophilic aromatic substitution polycondensation with various molar feed ratios of bisphenol monomer, 2-(4-phenoxyphenyl)-1,4-diphenol to (3,5-ditrifluoromethyl)phenylhydroquinone. The molecular weights ( Mn values), polydispersities and Tg values of 6FPOP-PEEKs increase as the molar feed ratio of 6FPH/(6FPH+POPH) increases. These 6FPOP-PEEKs show very high thermal stability. At a wavelength of 1550 nm, the refractive indices of the 6FPOP-PEEKs films are in the range of 1.5992–1.6396 and birefringences are in the range of 0.0034–0.0043. The near-infrared spectra show that the 6FPOP-PEEK films have small light absorption at the telecommunication wavelengths of 1300 and 1550 nm.

The aromatic bisphenol monomers containing bulky pendant (adamantyl) groups, 4-(1-adamantyl)-1,3-benzene diol (AdRES) and 4,8-bis(1-adamantyl)-1,5-dihydroxy naphthalene (AdNp) were successfully prepared via the Friedel—Crafts reaction and used to synthesize a series of new poly (aryl ether ketone) copolymers with (3-trifluoromethyl) phenyl hydroquinone or other bisphenols and 4,4′-difluorobenzophenone (DFB) by nucleophilic aromatic substitution polycondensation. All the novel PAEKs were amorphous and their solubility was improved by the introduction of bulky pendant groups, so they were readily soluble in common organic solvents. DSC data showed that Tg values of the resultant copolymers were dramatically increased when adamantane is incorporated into the copolymers as a pendent group and their T g values increased with increasing content of adamantyl groups. According to thermogravimetric analysis, all the polymers showed excellent thermal stabilities. The mechanical properties of the polymers can be controlled by varying the molar ratio of diphenol-containing adamantyl to (3-trifluoromethyl) phenyl hydroquinone. These novel poly (aryl ether ketone) films had low dielectric constants ranged from 2.62 to 2.95 at 1 MHz and low water absorptions of 0.12—0.29%; their dielectric constants decreased with the increasing content of the adamantyl group.

New poly(arylene ether sulfone)s have been synthesized by solution polycondensation reaction of 2,4-bis[(4-chlorophenyl)sulfonyl]-1-(phenylthio)benzene)] with 4,4'-(9-fluorenylidene) bisphenol (FBP) and phenolphthalein (PP). The chemical structure of the polymers was confirmed by using both spectroscopical (FTIR, 1H-NMR) and elemental analysis methods. All the polymers were soluble in aprotic dipolar solvents. The thermal properties were investigated by differential scanning calorimetry and thermogravimetric analysis, and they, were discussed in connection with the chemical structure of the polymers. The investigation of optical properties by photoluminescence spectroscopy revealed that all the polymers displayed one emission peak in the blue domain beetwen 449 and 460 nm.

The properties of the ternary matrix system (EPB), obtained by the reactive blending of epoxy resin - diallyl bisphenol and a bismaleimide, depend on the structure and properties of its components. The influence of the structural variations of bismaleimide on the thermal, physical and mechanical properties of the ternary blend was examined. EPB compositions were prepared using novolac epoxy, diallyl phenol A and three different bismaleimide systems viz. 2, 2-bis 4-(4 maleimidophenoxy) phenyl propane-BMIP, bis (4-maleimidophenyl) methane-BMIM and bis (4-maleimido phenyl) ether-BMIE. The EPB systems with different types of bismaleimides were processed and characterized for their thermal, physical and rheological properties. EPB-glass composites processed using these matrix systems were characterized for their thermo-physical and mechanical properties. High temperature properties of these systems were assessed by their adhesive strength retention at different temperatures. The EPB system formed by the reactive blending of epoxy- phenol system with BMIP was found to yield the blend with improved mechanical performance at ambient conditions, while that with BMIM proved to be the best for high temperature application.

By blending electrically conducting carbon black particles and silica into poly(bisphenol A-co-epichlorohydrin) epoxy resin polymer, conductive nanocomposites were prepared by printing onto transparency films and curing. Application of a milling procedure prior to application is beneficial for the reduction of cracks in the subsequent nanocomposites. Electrical conduction of nanocomposite is CB content dependent. A percolation region (19—24% CB on mass of resin) exists where the nanocomposite exhibits a transition from an electrical insulator to conductor. Nanocomposites with 14% and 19% CB on mass of resin demonstrated greatest sensitivity to changes in bending angle, attributed to greater localized changes in the conductive paths within a semi-conducting sensor. Good reproducibility was observed as a result of molecular interactions between CB particles and the epoxy resin.

The influence of the ratio of epoxy (EP) to dicyclopentadiene bisphenol cyanate ester (DCPDCE) on the curing behavior of EP/DCPDCE system was studied using differential scanning calorimetry and Fourier transform infrared spectroscopy. The conversion of —OCN groups and the formation of the reaction products in the different EP/DCPDCE systems and at different curing steps were determined. The results show that the epoxy resin has both a catalytic effect and a dilution effect on the trimerization reaction of —OCN groups. These two effects reach an approximate balance when the content of epoxy resin in the EP/DCPDCE system is 15 wt.%. In addition, the epoxy resin can improve the final conversion of —OCN groups, and the initial amount of epoxy resin has a significant influence on the final structure of the co-polymers.

Dental composites undergo material property changes during exposure to the oral environment and may release compounds of potential toxicity, such as bisphenol A. Degradation of dental composites was studied in a simplified overlayer model in which bisphenol A diglycidyl methacrylate (BisGMA) was covalently bound to a porous silicon oxide surface. It was hypothesized that the chemical structure of this overlayer would allow release of bisphenol A, BisGMA, and the decomposition products thereof, upon exposure to water for an extended period. Liquid chromatography mass spectrometry found leaching of intact BisGMA and several degradation products that contained the bisphenol A moiety from the overlayer into distilled water after 2 wks of aging. The absence of bisphenol A release from the overlayer reduces concerns regarding its potential health risk in dental composites. Nevertheless, health concerns might arise with respect to BisGMA and the leached degradation products, since they all contain the bisphenol A moiety. Abbreviations: BisGMA, bisphenol A diglycidyl methacrylate; HPLC, high-performance liquid chromatography; LCMS, liquid chromatography mass spectrometry; MA, methacrylic acid; MPS, 3-(trimethoxysilyl) propyl methacrylate; m/z, mass-to-charge ratio; and TIC, total ion chromatogram.

A new semi-fluorinated perfluorocyclobutyl (PFCB) aryl ether containing polymer was prepared in high yield via the condensation of a commercial 4,4'-((1,2,3,3,4,4-hexafluorocyclobutane-1,2-diyl)bis(oxy))bisphenol (bisphenol T) and bis(trifluorovinyloxyether)biphenyl producing transparent, flexible films. The polymer system was structurally characterized using 1H and 19F NMR and exhibited a high degree of thermal stability as determined by thermogravimetric analysis capacity. The sulfonated analogue showed the highest degree of sulfonation at 27% from ion-exchange chromatography, producing a conductivity of 0.011 S cm-1 at 100% relative humidity.

The chemistry and properties of polymers containing the “fire smart” moiety 1,1-dichloro-2,2-diphenylethene (DDE) are described. These polymers are typically derived from the bisphenol of chloral (bisphenol-C/BPC) and are low cost, easily processed, and have good mechanical properties and toughness under normal conditions. Under fire conditions, the DDE group undergoes an intramolecular rearrangement with the elimination of hydrogen chloride (a noncombustible gas) and intermolecular crosslinking to form an aromatic char residue in high yield. The flammability and mechanical properties of DDE-containing polymers are described.

A series of new soluble, thermally stable polymers that contain phenylthiourea and azo groups in the polymer backbone were synthesized from a novel bisphenol and diacid chlorides. The novel bisphenol containing phenylthiourea and azo groups was synthesizedinthreesteps. In the first step, 4,4‘-bis(thiourea) biphenyl (BTB) was from 4,4‘-diaminobiphenyl and ammonium thiocynate. The second step involved the diazodization reaction of 4-aminophenol to give the diazonium chloride salt. The third step in the preparation of the monomer was the coupling of bisthiourea (BTB) with the diazonium chloride in the presence of an alkali which resulted in 4,4‘-bis( p-hydroxyphenyl azo thiourea)biphenyl (HP-ATB). The final step was the synthesis of polyesters by polycondensation reaction of this monomer with various acid chlorides (both aromatic and aliphatic). The materials were characterized by solution viscosity, UV-Vis, Fourier transform infrared spectroscopy, 1H NMR, differential scanning calorimetry and thermogravimetric analysis. Solubility of the polymers was also tested with different solvents, which can be an important parameter for the processability of the polymer. The synthesis and characterization of the novel monomer and polymers is discussed herein.

A series of low-melting phthalonitrile oligomers were prepared in which variable-length multiple aromatic ether linkages interconnect the terminal phthalonitrile units. These materials were designed to address the need for a processable resin system with good high-temperature properties. The melt-processable oligomers are obtained using a modified-Ullman ether reaction between a bisphenol and a dihalobenzene to form a hydroxyl-terminated oligomeric intermediate that is endcapped by reaction with 4-nitrophthalonitrile. Viscosity measurements show that the phthalonitrile oligomers are polymerized at a moderate temperature (200°C) using the typical aromatic diamine curing additives, bis[4-(4-aminophenoxy)phenyl]sulfone and 1,3-bis(3-aminophenoxy)benzene. The oligomeric phthalonitrile/diamine mixtures exhibit a low complex melt viscosity (0.01-0.1 Pa s) at 200°C. Differential scanning calorimetric analysis is used to follow the polymerization as the oligomeric phthalonitrile/diamine mixtures are heated to elevated temperatures. Thermal and dynamic mechanical properties of thermally-cured oligomeric phthalonitrile polymers are systematically evaluated and compared with those of two other high temperature thermosetting phthalonitrile polymers, 4,4~-bis(3,4-dicyanophenoxy)biphenyl and 1,3- bis(3,4-dicyanophenoxy)benzene. After thermal treatment at 425°C for 8 h, the oligomeric phthalonitrile polymers exhibit char yields of 70% when heated to 1000°C in flowing nitrogen and decomposition temperatures in excess of 500°C when heated in either flowing nitrogen or air. Rheometric measurements indicate that the fully cured oligomeric phthalonitrile polymers do not soften or exhibit a glass transition temperature upon heating to 450°C. Overall, studies on the phthalonitrile oligomers and the corresponding polymers reveal an attractive combination of processability, thermal and thermo-oxidative stability and good dynamic mechanical properties for these materials

The characterization of electron beam (E-beam) curing of diglycidyl-ether of bisphenol A-diaryliodonium hexafluoroantimonate epoxy resin-initiator system is reported as a function of (i) diaryliodonium hexafluoroantimonate catalyst (initiator) concentrations of 0.1-10 parts per hundred (phr) and (ii) total electron beam doses of 5-150 kilogray (kGy). The in situ E-beam temperature of the resin is monitored as a function of dose-time characteristics. The degree of cure is monitored after radiation exposure by Fourier transform infrared spectrometry (FTIR) and the glass transition temperatures (Tg) by differential scanning calorimetry (DSC). The degree of cure and cure rate increased with total dose exposure and initiator concentration. The maximum cure rate occurred at 5 kGy exposure and, thereafter, decreased as reactive species concentration decreased. The maximum in situ E-beam temperature of 76°C was recorded for the resin containing 10 phr of initiator, with a maximum degree of cure of 94% and a glass transition temperature of 86 C, indicating that the cure reactions under E-beam are glassy state diffusion controlled. The resin glass transition temperatures are considerably lower than the thermally cured glass transition temperatures of 170 C because of H2O termination reactions at the lower E-beam cure temperatures that result in a poor cross-linked network. In addition, the diaryliodonium hexafluoroantimonate catalytic activity for epoxide cationic polymerization is retarded by H2O. E-beam exposure causes the diaryliodonium hexafluoroantimonate to dissociate into active catalytic species, such as HSbF6, well below 100°C compared to catalytic thermal induced dissociation near 200°C. The E-beam cure reaction rate is modeled as a function of degree of cure and dose exposure by a standard autocatalytic kinetic model.

Three kinds of phosphate-containing maleimide(PMI) monomers, namely diethyl (4-(N-maleimido) phenyl) phosphate (4P) diphenyl (4-(N-maleimido) phenyl) phosphate (PP) and diethyl (2,6-dibromo-4-(N-maleimido)phenyl) phosphate (BrP), were synthesized and blended with a bisphenol type epoxy so as to study their potential as reactive flame retardants. It was expected that with an increase in the PMI content in the blending system, the Michael-addition reaction would take place more and easily. Increasing the PMI contents reduced the storage modulus, the Tg and the tensile strength, however good thermal stability was maintained. The flame retardancy of all the phosphate-containing epoxy systems was promoted significantly by increasing the PMI content.

Bisphenol A-based cyanate ester resin (BADCy) was modified with different amounts of bismaleimide (BMI) to improve the thermomechanical properties of the parent resin. The DSC investigation of the curing of mixtures of BADCy and BMI suggested that they cured in one single step and addition of BMI shifted the cure initiation and peak curing temperatures of BADCy to higher temperatures. The addition of BMI delayed the gelation times of BADCy. The BMI modification of BADCy did not seem to affect the high Tg of BADCy but a marginal increase in water absorption was seen. Flexural strength of carbon composites with BADCy increased considerably upon modification with BMI. The elevated temperature testing of carbon composites made with BMI-modified BADCy suggest that they retain their advantageous mechanical properties quite well even at 120 C.

Diallyl bisphenol A–formaldehyde copolymer (ABPF) was addition cured with bisphenol A bismaleimide (BMIP) making use of the Alder-ene reaction at high temperatures. The lap shear strength (LSS) of the system was found to depend on the conditions of cure and the stoichiometry of the reactants. Moderate cross linking achieved at a 1:1 maleimide:allylphenol stoichiometry and a stepwise cure, up to a maximum of 250 °C for 2 h, was found to be the most effective in achieving the optimum LSS properties. The system exhibited greater than 100% retention of the LSS at temperatures up to 250 °C. Matrix modification using polysulfone (PS) and polycarbonate (PC) resulted in a remarkable improvement in the adhesive characteristics, although the high-temperature retention was marginally adversely affected. The performance advantage both at room temperature (RT) and at high temperature was greater in the case of PS modification, showing an optimum improvement at 20% loading as against PC modification, exhibiting maximum properties at 10% loading. Scanning electron microscopy (SEM) analysis confirmed that the fine dispersion of PS, rather than large size nodules found in PC, was conducive for the better performance of the former. Dynamic mechanical analysis (DMA) corroborated the observations made in SEM. The existence of co-continuous phases of thermoplastic, matrix and thermoplasticdissolved matrix was evidenced in the PS modification and a clear phase separation was evident in the case of the PC modified system, manifesting independent glass transitions by the individual phases.

Polycondensations of bisphenols such as bisphenol-A (BPA), bisphenol-AF (BPAF) and bisphenol-S (BPS) with bis(4-chloro-3-nitrophenyl) sulfone (BCNPS) were examined using various organic or inorganic bases in mixed solvents of DMAc with water or in plain water. The reactions of bisphenols (BPA, BPAF and BPS) with BCPNS proceeded smoothly to give the corresponding polyethers (P-1, P-2 and P-3) in mixed solvents of DMAc with water at 60 °C using 1, 8-diazabicyclo[5.4.0]undecene-7 (DBU) as a base, although the rate of the reaction decreased gradually as the water in the solvent increased. Polyethers P-1, P-2 and P-3 can also be obtained by the reaction in plain water using appropriate organic bases such as DBU, triethylamine, and 4-( N, N-dimethylamino)pyridine. It was also found that P-1 with relatively high molecular weight was synthesized in high yield when the reaction of BPA with twice the amount of BCNPS was performed using DBU at 60 °C for 48 h in plain water.

Polyoxazolidones of different crosslink densities were prepared by reacting NCO-terminated oxazolidone quasi-prepolymers with diglycidyl ether of bisphenol A. The NCO-oxazolidone quasi-prepolymers were prepared at a 5/1 NCO/epoxy ratio, utilizing three different types of isocyanates: 4,4'-methylene bis(phenyl isocyanate) (MDI), polymeric MDI (PMDI) and 4,4'-methylene bis(cyclohexyl isocyanate) (H12MDI). These resins were prepared at isocyanate indices of 105 and 120, and in the case of PMDI, with an additional index of 200. The viscoelastic properties of these resins during curing were studied using rheometric dynamic spectroscopy. The chemical structure of the NCO-terminated oxazolidone quasi-prepolymers and of the resulting poly-oxazolidones were determined using infrared spectroscopy. Stress-strain response, flexural strength and modulus, compressive strength and modulus and shear strength were evaluated, as well as adhesion properties (lap shear strength). The measured properties were found to be very good for all types of the polyoxazolidones. Practically all polyoxazolidones retained over 50% of the room temperature tensile strength at 150°C. Room temperature lap shear strength of polyoxazolidone adhesives changed slightly at 150°C, and in the case of PMDI-based polyoxazolidone adhesive at an isocyanate index 120 did not change after immersion in boiling water for 3 hours. The high temperature performance of the polyoxazolidones was also confirmed by the excellent retention of mechanical properties after aging for seven days at 150°C as well as by dynamic mechanical analysis (DMA) and thermo-mechanical analysis (TMA).

Various polycynaurates were synhesised by stirred interfacial polycondensation of 2-(N.N-diphenynhydrazino)-4,6-dichloro-s-triaziae (DPHDCT) with each of the aromatic diols: bisphenol-A (BPA); bisphenol-C (BPC); bisphenol-S (BPS); phenolphthalein (Ph); catechol; resorcinol; 1,5and 2.7-dihydroxynaphthalene (DHN-1,5 and DHN-2,7) and 1,8-dihydroxyanthraquinone (DHA-1,8). Interfacial polycondensation of DPHDCT with BPA was investigated in detail in order to select optimum reaction conditions. The yield of polycyanurates varies from 6 I% to 79%. The polycyanurates are soluble in chlorinated solvents such as chloroform, dichloroethane. dichloromethane and chlorobenzene. The reduced viscosity for polycyanurates, determined with a 1 g disolution in chloroform at 25 + 3°C was found to be in the range 0.50-0.68 dl g. All the polycyanurates were characterized by IR spectra. The densities of the polycyanurates, determined using the suspension method at 25 3°C, range between 1.196 and 1.330 g cm. The overall reactivity of diols, based on reduced viscosity values, was found to decrease in the following order: PCBPA> PCPh> PCBPC> PCR>PCDHN-2,7 > PCDHN-I,5 > PCC > PCDHA-1.8 > PCBPS. The thermal stability of polycyanurates, derived from various temperature characteristics, was found to decrease in the following order: PCBPA> PCBPS> PCBPC > PCC PCR> PCDHN-2,7 PCDHN-.l 5 > PCDHA-1,8 > PCPh.

The curing reaction of liquid epoxy resin based on l,l'-bis(4-hydroxyphenyl) cyclopentane with different amines, in the presence or absence of a fortifier, has been studied by differential scanning calorimetry (DSC). The glass-fibre-reinforced composites of liquid diglycidyl ether of bisphenol-P (DGEBP) were prepared using different amines as curing agent with/without fortifier and evaluated for their physical properties (such as density,% resin content and% void content) and mechanical properties (such as flexural strength, interlaminar shear strength and shore-D hardness). The laminates were also evaluated for their chemical resistance and electrical properties. It was found that using an epoxy fortifier (PGEHA) reduces the mechanical properties of the DGEBP-curing agent system.

A homologous series of four aromatic polyesters and two series of copolyarylates were synthesized under phase-transfer conditions from monomers containing the isopropylidene (IP) and/or the hexafluoroisopropylidene (HFIP) moiety. The homopolymers were obtained in good yields, were soluble in common organic solvents, and would readily form clear, colorless films from solution. Thermal stabilities in air (dynamic-10% weight losses at 440°C-490°C; isothermal-100 h at 350°C, 7%-86% weight loss) revealed that resistance to thermo-oxidation was highest when the HFIP group replaced the IP moiety in the bisphenol rather than in the diacid. Other properties of the homopolymers which were measured were water absorption of 0.07%-0.35% (by weight), and the dielectric constant of 2.32 for the fully fluorinated polymer. Copolymers were prepared from mixtures of bisphenols A and AF, and each of the two diacids. The thermal stability and water absorption of both series were measured as functions of BPAF content. No significant change in properties was observed for copolymers with less than 70 mol.% BPAF comonomer.

Post-source decay (PSD) experiments using a matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spec trometer have been applied to the structural determination of polycarbonates. We investigated linear and cyclic structures of polycarbonates derived from bisphenol A and a linear and a cyclic polycarbonate derived from 4,4′-dihydroxydiphenyl-3,3-pentane as well as a linear polycarbonate derived from bisphenol Z. The fragmentation behavior of these polycarbonates is similar to the mechanism proposed in the literature for electron impact and static secondary-ion mass spectrometry measurements, but depends on the substituents bound to the central carbon atom of the bisphenol unit. Knowing the fragmentation mechanism of polycarbonates, the PSD-MALDI mass spectrum of a linear chain allows the masses of both end groups to be infered. However, it is shown that variation of the substituent on the bisphenol unit has a strong influence on the fragmentation behavior, so that cleavage of the polymer backbone may be suppressed and the spectra are dominated by the loss of side chains.

The status of denture-base poly(methylmethacrylate) (PMMA) has been reviewed, and in spite of the availability of mechanically superior injection-molded resins, it remains the material of choice. PMMA can be reinforced with fibers, the most recent being ultra-high-modulus polyethylene fibers. Various elastomer reinforced materials are also available. Alternatives to room-temperature polymerizing PMMA resins include higher methacrylates and epimine resins. High-modulus resins have been produced with Bisphenol A-glycidyl methacrylate (BisGMA) and tetrahydrofurfuryl methacrylate, involving an anti-plasticizer function. Also reviewed are room-temperature polymerizing initiators, radio-opaque resins, and studies on polymerization shrinkage.