Interacting Blends of Novel Acrylated Poly(Ester Amide)s Based on DGEBC with Styrene Monomer

Bisphthalamic acids were prepared by reaction of phthalic anhydride and aromatic diamines. Novel poly(ester amide) resins (PEAs) were prepared by reaction between diglycidyl ether of bisphenol-C with bisphthalamic acids using a base catalyst. Post reactions of all these PEAs were carried out with acryloyl chloride. The resultant products are designated as acrylated poly(ester amide) resins (APEAs). The PEAs and APEAs were characterized by elemental analysis and number average molecular weight determined by nonaqueous conductometric titration method. IR spectra of PEAs and APEAs were also recorded. Blending of these APEAs with styrene monomer were carried out. The curing of these APEAs-styrene blends was monitored on a differential scanning calorimeter (DSC) by using benzoyl peroxide as a catalyst. Based on DSC data, glass fiber-reinforced composites of APEAs-styrene blends have been fabricated and their chemical, mechanical and electrical properties have been evaluated. Unreinforced cured samples of APEAs-styrene blends were analyzed thermogravimetrically.     

Synthesis,Characterization and Glass Reinforced Composites of Acetone-Formaldehyde - Resorcinol Resins

Abstract

Acetone-Formaldehyde (AF) resin having methylol groups ([sbnd]CH₂OH) has been prepared and condensed with resorcinol (R) in the presence; of alcoholic alkali catalyst at varying ratios of AF:R; 1:1, 1:1.5 and 1:2. The resultant AF-R resins were characterized by elemental analysis, IR spectral studies, number average molecular weight (Mn) estimated by non-aqueous conductometric titration and thermogravimetry. The curing study of AF-R resins with Hexamethylenetetramine (HMTA) was monitored by Differential Scanning Calorimetry (DSC) and kinetic parameters were evaluated. The glass reinforced composites based on AF-R-HMTA system have also been prepared and characterized.     

Characterization of an alkali‐treated grass fiber by thermogravimetric and X‐ray crystallographic analysis

The thermal behavior of grass fiber was characterized by means of thermogravimetric analysis and differential scanning calorimetry analysis. The results proved that the removal of water‐soluble matter improved the thermal behavior of grass fiber over that of unleached fiber, and this was further enhanced by an alkali treatment of the grass fiber. The isothermal weight loss of the grass‐fiber specimens was analyzed at 100, 200, and 300°C for different time periods. Accelerated aging of the grass‐fiber samples was carried out to determine the effect of aging on the tensile strength. Partially delignified grass fiber showed maximum thermal stability. X‐ray diffraction analysis was also performed to verify the composition and to correlate the change in the tensile strength due to the water leaching and alkali treatment. The processing of grass fiber with NaOH and NaClO₂ reduced the amorphous fraction in the fiber sample. This may have been a result of the loss of the amorphous noncellulosic components of the fibers and the degradation of the unordered regions of the grass fiber. However, mercerization of the grass fiber revealed an increase in the amorphous fraction after a certain time exposure, confirming the decrease in the crystallinity. The morphology of the water‐leached and alkali‐treated grass fiber was studied with scanning electron microscopy © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Synthesis,Characterization and Glass Reinforcement of Poly(Ester Amido Imide)s

Poly(ester amido imide)s (PEAI)s (IIIa–e) were prepared by the intermolecular Diels-Alder (DA) reaction of bismaleimide (II) having epoxy resin segment with various bisfurans (Ia–e) having amide bridge. The DA reaction was carried out with tetrahydrofuran as a solvent, as well as in bulk, followed by aromatization of DA polyadduct intermediates in the presence of acetic anhydride. All the resultant polymers, designated as poly(ester amido imide)s (PEAI)s, were characterized by elemental analysis, number average molecular weight, IR spectral studies and thermogravimetry. The PEAIs exhibit good thermal stability. Bismaleimide (II) and bisfurans (Ia–e) were polymerized (at 150 ± 10°C) by in situ DA intermolecular reaction into moderately thermally stable PEAIs. The glass fiber-reinforced composites (i.e., laminates) of all PEAIs were prepared and characterized by their chemical resistance and mechanical properties.     

Synthesis and performance of phenolic polybutadiene‐bound stabilizers

An antioxidant derivative, 6‐sulfanylhexyl 3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl)propanoate, was synthesized and examined. With a radical initiator, the addition of this compound to pending vinyls of OH‐telechelic, low molecular weight liquid polybutadiene (LBH) was performed to various degrees of conversion to form polymeric antioxidants (PAOs) in which the phenolic moiety was separated from the main chain by a spacer [? CH₂CH₂? S? (CH₂)₆? O? CO? ]. Pure, unstabilized LBH was mixed in several ratios with PAOs, Irganox 1520, and Irganox 1076, and the oxidation stabilities of these mixtures, determined by thermogravimetric analysis and differential scanning calorimetry, were compared. Probably because of their good compatibility with LBH, PAOs exhibited equal or better effectiveness than commercial antioxidants of the Irganox type. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 87: 885–889, 2003     

Synthesis,characterization, and thermal properties of copolymers of behenyl acrylate and behenyl fumarate

Radical copolymerization of behenyl (systematic IUPAC nomenclature: n‐docosyl) acrylate and behenyl fumarate has been carried out in toluene at 70°C using benzoyl peroxide as initiator. Gel permeation chromatography was used to determine molecular weights (MW) and molecular weight distribution (MWD) of behenyl acrylate–behenyl fumarate (BA‐BF) copolymers. ¹H NMR and carbon analysis was used to determine the composition of BA‐BF copolymers. Monomer reactivity ratios for high conversion polymerization were calculated by conversion‐extended Kelen‐Tudos plot. Differential scanning calorimetric (DSC) measurements shows sharp melting peaks at about 64°C. Thermal stability studies were performed with thermogravimetric analyzer (TGA). By using these DSC and TGA data in several nonisothermal methods, the activation energies were calculated. X‐ray diffraction studies show the linearity of the copolymers. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 2721–2726, 2003     

Synthesis,Characterization and Glass/Carbon Reinforcement of Acetone-Formaldehyde-1,5-Dihydroxynaphthalene-Epoxy Resin System

Acetone-formaldehyde (AF) resin containing the methylol group (–CH₂OH) has been prepared and condensed with 1,5-dihydroxynaphthalene (DN) in the presence of an alcoholic alkali catalyst at varying ratios of AF:DN: 1:1, 1:1.5 and 1:2, respectively. The resultant AFDN resins were characterized by elemental analyses, IR spectral studies, and number average molecular weight determined by the nonaqueous conductometric titration method. Further reaction of the AFDN resins was carried out with different epoxy resins (i.e., DGEBA, DGEBC and DGEBF). The curing of these resins was monitored by differential scanning calorimeter (DSC) and their kinetic parameters have been evaluated. Based on DSC thermograms both glass and carbon fiber-reinforced composites have been laminated and characterized for chemical, mechanical and electrical properties. The unreinforced cured resins were subjected to thermogravimetric analysis (TGA).     

Synthesis and characterization of sPS/montmorillonite nanocomposites

The present work analyzed the possibility of obtaining and producing syndiotactic polystyrene (sPS)–based nanocomposites. The work first focused on possible technology to use for intercalation from solution and melt intercalation. Using a blend of sPS with atactic polystyrene (aPS) as the matrix was also considered. Thermal analysis techniques, such as differential scanning calorimetry (DSC) and thermogravimetry (TGA), were used to study the thermal properties and stability of the nanocomposites obtained and to select the most appropriate nanocharges. The effect of the introduction of nanofillers on these properties also was evaluated. X–ray diffraction was used to investigate the degree of clay exfoliation. Finally, mechanical characterization of the nanocomposites obtained was performed and compared to that of the pure material. The tests demonstrated that nanodispersion of phyllosilicate layers improved the mechanical behavior of the polymers analyzed, especially the annealed sPS. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 4957–4963, 2006     

Thermal and nondestructive analysis of high density polyethylene filled with milled salago fiber

Fillers are utilized for different purposes. In plastic industry, fillers are mainly used to extend the bulk of the compound; however, they can also improve physical properties, materials processing, and reduce cycle time of plastics. In this article, high-density polyethylene was filled with untreated and 5% alkaline-treated salago fiber, and thereafter the thermal and nondestructive properties of the composites were investigated. It was found that the chemical treatment of fiber increased the thermal stability and the mean coefficient value of linear thermal expansion of the treated composites as compared to the untreated ones. Moreover, the increase of fiber content in composites increased the crystallinity level while decreased the thermal capacity and melting temperature of the composites. The zinc, calcium, and phosphorus contents were found to be within the industry-acceptable range for elemental contents in polyolefins. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47873.     

Synthesis,Characterization and In Vitro Antibacterial Activity of Coordination Polymers Based on Bis Bidentate Ligand

A novel bis (bidentate) ligand, namely 5, 5′- (2, 2′- (phenyl azanediyl) bis (ethane-2, 1 - diyl) bis (oxy) bis (methylene) diquinolin ?8 - ol) (PBEQ), was synthesized by condensation of 5 –chloromethyl ?8 - hydroxyquinoline hydrochloride with N, N – Di (2 - hydroxy ethyl) aniline in the presence of a base catalyst. This ligand was characterized by IR, ¹H-NMR, and elemental analysis. Coordination polymers of this bis-ligand (PBEQ) were prepared with Cu(II), Ni(II), Co(II), Mn(II), and Zn(II) metal ions. All of these coordination polymers were characterized by elemental analyses, IR spectral and diffuse reflectance spectral studies. The thermal stability was evaluated by thermogravimetric analyses. In addition, all of the coordination polymers have been characterized by their magnetic susceptibilities. The microbicidal activity of all the samples has been monitored against plant pathogens.     

The effect of formaldehyde/phenol (F/P) molar ratios on function and curing kinetics of high‐solid resol phenolic resins

A series of high‐solid resol phenolic resins (HSRPRs) were synthesized with different molar ratios (1.6, 1.8, 2.0, 2.2, and 2.4) of formaldehyde to phenol using calcium oxide and sodium hydroxide as catalyst. The effects of F/P molar ratios on physical properties, free formaldehyde and phenol, activity, structure, and thermally resistant properties of HSRPRs were fully investigated by chemical assays, liquid and solid ¹³C‐NMR, Fourier transform infrared spectroscopy, and thermogravimetric analysis. The curing kinetics of different F/P molar ratios were explored with differential scanning calorimeter at four different heating rates (5, 10, 15, 20°C/min) from 35 to 200°C. Overall, HSRPRs with F/P = 2.0 had excellent comprehensive properties. The study was significant in solving the wastewater problem during the process of industry‐scale preparation of HSRPRs. We believed that the experimental findings would provide a new avenue for further study and application of HSRPRs. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis of UV and thermal dual curing oligomer for solder resist ink using ink-jet printing

A novel solder resist ink for inkjet printing containing the ultraviolet (UV) and thermal dual curing oligomer is introduced in this work. Three kinds of acrylic monomers for the synthesis of the oligomer are successful prepared and their structures are determined by Fourier transfer infrared. Both UV curing process and thermostability are monitored under UV differential scanning calorimetry and thermogravimetric analysis. For the photoreaction process, the oligomer using Lauryl methacrylate as the material of copolymerization possesses the highest reactivity and conversion of carbon–carbon double bond. Besides, this kind of oligomer also owns excellent thermostability, just losing 5.9% of its weight at 288 °C. The solder resist inks containing the oligomers and jetting by the inkjet printer are tested with the adhesion, soldering resistance, and other performances, presenting the outstanding heat resistance and wide application prospects. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47428.     

Synthesis and CO2 separation of novel polyurethane membranes containing urea linkages

We synthesized novel polyurethane (PU) membranes from isophorone diisocyanate (IPDI), poly(ethylene glycol) (PEG) with a molecular weight of 2000, aminopropyl-terminated poly(dimethyl siloxane) (PDMS) with a molecular weight of 2000, and 1,4-butanediol (BDO) via a two-step polymerization. The structure of each synthesized membrane was studied through Fourier transform infrared spectroscopy and gel permeation chromatography. The effect of the thermal behavior was determined by differential scanning calorimetry and thermogravimetric analysis. The gas-permeability characteristics of the PU membranes were then tested for a single gas. The results show that the permeability of CO₂ (P_CO2) gradually increased with PDMS content. Among these PU membranes, PU-d (PEG/PDMS = 1:1, PEG/PDMS/IPDI/BDO = 1:3:2) showed the best P_CO2 (132.6 Barrer) at 25°C and 1 bar pressure. The gas-permeability coefficients of each PU membrane at different operating temperatures were investigated, and the results show that P_CO2 reached 302.6 Barrer at 65°C and 1 bar. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47723.     

Studies and characterization of RESOL/VAc–EHA/HMMM IPN systems in aqueous medium

Resol was solution‐blended with vinyl acetate‐2‐ethylhexyl acrylate (VAc–EHA) resin in an aqueous medium, in varying weight fractions, with hexamethoxymethylmelamine (HMMM) as a crosslinker and the data were compared with a control. The present work was aimed to obtain an optimum combination of high‐temperature resistance by synthesis of an interpenetrating network (IPN) of the resins. The control gave a semi‐IPN system, in which the resol crosslinked, while the acrylic did not, whereas the blend, where HMMM was the crosslinker, gave a full‐IPN system. FTIR spectra of the blends of resol/VAc–EHA/HMMM indicated the formation of new stretching, which was generated due to crosslinking reactions among VAc–EHA and the crosslinker HMMM. TGA showed that, with an increase in the VAc–EHA percent in semi‐IPNs, the decomposition temperature decreased gradually, whereas in case of full‐IPNs, the decomposition temperature increased with increase in the VAc–EHA percent. However, the full‐IPNs had a higher decomposition temperature than that of the semi‐IPNs, at the same resol/(VAc–EHA) ratio. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 3581–3588, 2002