Miscibility and interpolymer complexation of poly(2-methyl-2-oxazoline) with hydroxyl-containing polymers

Poly(2-methyl-2-oxazoline) (PMOx) was found to be miscible with poly (styrene-coallyl alcohol), poly(hydroxyether of bisphenol-A), poly (2-hydroxypropyl methacrylate) and poly(p-vinylphenol) (PVPh), when cast from N,N-dimethylformamide solutions and to form interpolymer complexes with PVPh in methanol solutions. The hydrogen bonding interactions between PMOx and hydroxyl-containing polymers were studied by infrared spectroscopy and compared with the corresponding blends of poly(2-ethyl-2-oxazoline) (PEOx). Except with phenoxy, PMOx interacts more strongly with hydroxyl-containing polymers than PEOx does.     

Miscibility and complexation behavior of poly(cyanomethyl methacrylate) and poly(2-cyanoethyl methacrylate) with tertiary amide polymers

The miscibility and complexation behavior of poly(cyanomethyl methacrylate) (PCYMMA) and poly(2-cyanoethyl methacrylate) (PCYEMA) with various tertiary amide polymers was studied. PCYMMA and PCYEMA form interpolymer complexes with poly(N-methyl-N-vinylacetamide) (PMVAc) or poly(N-vinyl-2-pyrrolidone) (PVP) in tetrahydrofuran (THF) solutions. PCYMMA also forms complexes with poly(N,N-dimethylacrylamide) (PDMA) in THF solutions. However, PCYEMA does not form complexes with PDMA in THF solutions, but the THF-cast blends are miscible over the entire composition range. Both PCYMMA and PCYEMA do not form complexes with poly(2-ethyl-2-oxazoline) (PEOx) in THF solutions and are only miscible with PEOx when the blend contains greater than 60 wt % PCYMMA or 80 wt % PCYEMA. On the other hand, both PCYMMA and PCYEMA do not form complexes with PMVAc, PVP, or PDMA in N,N-dimethylformamide (DMF) solutions. The compositions of the complexes consist of simple mole ratios of the component polymers, and the glass-transition temperatures of the complexes are higher than those of the DMF-cast blends of similar compositions. Fourier-transform infrared spectroscopy provides further evidence on the miscibility behavior through changes in the amide carbonyl absorption bands of each tertiary amide polymer in the blends as well as in the cyano absorption band of PCYEMA. © 1995 John Wiley & Sons, Inc.     

Solution and solid‐state blend compatibility of poly(vinyl alcohol) and poly(methyl methacrylate)

The blend miscibility of poly(vinyl alcohol) and poly(methyl methacrylate) in N,N′‐dimethylformamide solution was investigated by viscosity, density, ultrasonic velocity, refractive index, and UV and fluorescence spectra studies. Differential scanning calorimetry and scanning electron microscopy were used to confirm the blend miscibility in the solid state. Blends were compatible when the concentration of poly(vinyl alcohol) was greater than 60 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2415–2421, 2006     

Miscibility of polysulfone and poly(ether sulfone) with tertiary amide polymers

The miscibility of polysulfone (PSf) and poly(ether sulfone) (PES) with three tertiary amide polymers has been studied. PES is miscible with poly(N-methyl-N-vinylacetamide) (PMVAc) and with poly(N,N-dimethylacrylamide) (PDMA) but not with poly(2-methyl-2-oxazoline) (PMOx). Miscible PES/PDMA blends show lower critical solution temperature behavior. However, PSf is immiscible with all the three tertiary amide polymers. Previous studies have shown that both PES and PSf are miscible with poly(N-vinyl-2-pyrrolidone). PES is also miscible with poly(2-ethyl-2-oxazoline) but PSf is not. Therefore, PES is more readily miscible with tertiary amide polymers as compared to PSf. Received: 23 October 1996/Revised: 11 November 1996/Accepted: 12 November 1996     

Blends of poly(vinyl butyral‐co‐vinyl alcohol) and poly(ethylene terephthalate‐co‐ethylene naphthalate): thermal,mechanical, and morphological properties

The miscibility behavior and morphology of a series of poly(vinyl butyral‐co‐vinyl alcohol) (PVBA) copolymers containing 29, 52, 76, and 88 mol % of vinyl alcohol units with poly(ethylene terephthalate‐co‐ethylene naphthalate) (PETN) was investigated by DSC and SEM. Blends of the PETN with PVBA were prepared by coprecipitation from a chloroform/o‐chlorophenol (20/80 wt %) mixture solvent. It was found that PVBAs with different vinyl alcohol content will form an immiscible phase with the amorphous PETN in the solution‐cast films. Also, PETN and PVBA with 29 mol % vinyl alcohol (PVBA‐29) are not miscible within the whole composition range. The glass‐transition temperatures of the blends were higher than those of the two‐component polymers. The values of the tensile properties of the blend films were also better than those of the original copolymer films. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2746–2751, 2001     

Synthesis and characterization of poly(2‐ethylaniline)–poly(styrenesulfonic acid) and poly(o‐phenetidine)–poly(styrenesulfonic acid) complexes

This research focuses on the synthesis of ethyl and ethoxy substituted polyaniline with poly(styrenesulfonic acid) comprising a poly(o‐phenetidine)–poly(styrenesulfonic acid) [P(O? P)‐PSSA] and poly(2‐ethylaniline)–poly(styrenesulfonic acid) [P(2‐E)‐PSSA]. The complexes P(O? P)‐PSSA and P(2‐E)‐PSSA were prepared by chemical polymerization of monomer (o‐phenetidine, 2‐ethylaniline) with PSSA using an oxidant of ammonium persulfate in 1M HCl solution; polyaniline (PANI), poly(2‐ethylaniline) (P2E), poly(o‐pheneditine) (POP), and polyaniline‐poly(styrenesulfonic acid) (PANI‐PSSA) also were prepared by chemical polymerization to be the reference samples. The products were characterized by IR, VIS, EPR, water solubility, elemental analysis, conductivity, SEM, and TEM. IR spectral studies shown that the structure of P(2‐E)‐PSSA and P(O? P)‐PSSA complexes is similar to that of polyaniline. EPR and visible spectra indicate the formation of polarons. The morphology of the blend was investigated by measured SEM and TEM, indicating the conducting component and electrically conductive property of the polymer complexes. The pH value for deprotonation [pH ≥ 9.5 for P(2‐E)‐PSSA and pH ≥ 8.0 for P(O? P)‐PSSA] are higher than that of corresponding HCl salts, indicating an intimate interaction between polymer chains. Elemental analysis results show that P(O? P)‐PSSA has a nitrogen‐to‐sulfur ratio of ～52%, larger than that for P(2‐E)‐PSSA, ～41%. The conductivity of the complexes is around 10^?2S/cm, and the solubility of P(2‐E)‐PSSA and P(O? P)‐PSSA in water is 2.9 and 1.9 g/L, respectively. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1198–1205, 2005     

Electrochemical synthesis and corrosion performance of poly(pyrrole-co-o-anisidine)

The electrochemical synthesis of poly(o-anisidine) homopolymer and its copolymerization with pyrrole have been investigated on mild steel. The copolymer films have been synthesized from aqueous oxalic acid solutions containing different ratios of monomer concentrations: pyrrole:o-anisidine, 9:1, 8:2, 6:4, 1:1. The characterization of polymer films were achieved with FT-IR, UV–visible spectroscopy and cyclic voltammetry techniques. The electrochemical synthesis of homogeneous-stable poly(o-anisidine) film with desired thickness was very difficult on steel surface. Therefore its copolymer with pyrrole has been studied to obtain a polymer film, which could be synthesized easily and posses the good physical–chemical properties of anisidine. The kinetics and rate of copolymer film growth were strongly related to monomer feed ratio. The introduction of pyrrole unit into synthesis solution increased the rate of polymerization and the substrate surface became covered with polymer film soon, while this process required longer periods in single o-anisidine containing solution. The protective behavior of coatings has been investigated against steel corrosion in 3.5% NaCl solution. For this aim electrochemical impedance spectroscopy (EIS) and anodic polarization curves were utilized. The synthesized poly(o-anisidine) coating exhibited significant protection efficiency against mild steel corrosion. It was shown that 6:4 ratio of pyrrole and anisidine solution gave the most stable and corrosion protective copolymer coating.     

Miscible blends of conductive polyaniline with tertiary amide polymers

Polyaniline (PANI) was doped with p-phenolsulfonic acid (PSA) or 5-sulfosalicylic acid (SSA). The PANI salts were blended with poly(N-vinyl-2-pyrrolidone), poly(N-methyl-N-vinylacetamide), poly(N,N-dimethylacrylamide), or poly(2-methyl-2-oxazoline) by solution casting from dimethyl sulfoxide. Blends containing up to 50% by weight of PANI salt were homogeneous and each exhibited a single glass transition temperature, indicating miscibility. Fourier transform infrared spectroscopic studies indicated that the carbonyl groups of the tertiary amide polymers interacted with the PANI salt as evidenced by the development of a shoulder at a lower frequency in the carbonyl stretching band. Electrical conductivities of the blends are in the range 10⁻⁵ to 10⁻³ S/cm, depending on the blend composition. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 68: 1839–1844, 1998     

Effect of poly(2-ethyl-2-oxazoline) and UV irradiation on the melt rheology and mechanical properties of poly(lactic acid)

To improve the suitability of poly(lactic acid) (PLA) for implantable devices, it ideally needs greater ductility without losses in strength. Here biodegradable poly(2-ethyl-2-oxazoline) (PEtOx) was selected as an additive to improve hydrophilicity of PLA as well as mechanical properties, while UV irradiation was considered as a bulk modification method to increase the long-term stability. The PLA blend showed improved tensile strength and elongation-at-break with small amounts of PEtOx added (1.5 wt %). Crosslinking by UV irradiation showed significant improvements with a dibutyltin dilaurate catalyst even though it produced a high degree of chain scission during melt processing. After UV irradiation for 150 h, the crosslinked material recovered mechanical properties and melt rheological properties comparable to the initial PLA-1.5%PEtOx blend (without catalyst added). Crosslinking was only possible with the added PEtOx present. A mechanism for the crosslinking reactions examined has been proposed since it has not been previously reported in the literature. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48023.     

Poly(N-1-alkylitaconamic acids)/poly(N-vinyl-2-pyrrolidone) blends

Blends containing poly(N-1-alkylitaconamic acids) (PNAIA) and poly(N-vinyl-2-pyrrolidone) (PVP) of two different weight average molecular weights, were studied by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and infrared spectroscopy (FTIR). The phase behaviour of the blends is analyzed in terms of the side chain structure and the specific interactions involved, mainly due to the free carboxylic group and the amide groups in PNAIA and the carbonyl group of PVP. The strength of the interaction was analyzed in terms of the Gordon-Taylor parameters. Received: 30 July 1997/Revised version: 3 November 1997/Accepted: 20 November 1997     

Preparation and characterization of castor oil‐based polyurethane/poly(o‐methoxyaniline) blend film

Blends made up of castor oil‐based polyurethane (PU) and poly(o‐methoxyaniline) (POMA) were obtained in the form of films by casting and characterized by FTIR, UV‐Vis‐NIR spectroscopy, and electrical conductivity measurements. Doping was carried out by immersing the films in 1.0M HCl aqueous solution. Chemical bonds between NCO group of PU and NH group of POMA were observed by means of FTIR spectra. The UV‐Vis‐NIR spectra indicated that the presence of the PU in the blend does not affect doping and formation of the POMA phase. The electrical conductivity research was in the range of 10^?3 S/cm. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Electrical properties of metal (indium)/polyaniline Schottky devices

Schottky devices were fabricated by thermal evaporation of indium on chemically synthesized polyaniline, poly(o-anisidine), and poly(aniline-co-ortho-anisidine) copolymer. Electrical characterization of each of these devices was carried out using current (I)-voltage (V) and capacitance (C)-voltage (V) measurements. The value of various junction parameters such as rectification ratio, ideality factor, and barrier heights of an In/poly(aniline-co-o-anisidine) Shootky device were found to be 300, 4.41, and .4972 V compared to the values of 60, 5.5, and 0.5101 V obtain for an In/polyaniline device, respectively. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65: 2745–2748, 1997     

Biaxially oriented films prepared from poly(vinyl chloride)/poly(methyl methacrylate co imide) blends

A study was conducted of blends of poly(vinyl chloride) (PVC) with a poly(methyl methacrylate co imide). The latter polymer was found to be miscible in PVC and to raise the glass transition temperature of the blend. Blends of all compositions could be oriented, but the processing temperature increased in proportion with T_g. For a given blend composition, orientation increased with increasing stretch ratio and strain rate and with decreasing stretch temperature. Increasing copolyimide content and increasing orientation generally lead to improved mechanical properties, though the blends containing high levels of copolyimide exhibited low ductilities.     

Increasing the compatibility of poly(l‐lactide)/poly(para‐dioxanone) blends through the addition of poly(para‐dioxanone‐co‐l‐lactide)

To modify the mechanical properties of a poly(l ‐lactide) (PLLA)/poly(para‐dioxanone) (PPDO) 85/15 blend, poly(para‐dioxanone‐co‐l ‐lactide) (PDOLLA) was used as a compatibilizer. The 85/15 PLLA/PPDO blends containing 1–5 wt % of the random copolymer PDOLLA were prepared by solution coprecipitation. Then, the thermal, morphological, and mechanical properties of the blends with different contents of PDOLLA were studied via differential scanning calorimetry (DSC), scanning electron microscopy (SEM), and tensile testing, respectively. The DSC result revealed that the addition of PDOLLA into the blends only slightly changed the thermal properties by inhibiting the crystallization degree of the poly(l ‐lactide) in the polymer blends. The SEM photos indicated that the addition of 3 wt % PDOLLA into the blend was ideal for making the interface between the PLLA and PPDO phases unclear. The tensile testing result demonstrated that the mechanical properties of the blends containing 3 wt % PDOLLA were much improved with a tensile strength of 48 MPa and a breaking elongation of 214%. Therefore, we concluded that the morphological and mechanical properties of the PLLA/PPDO 85/15 blends could be tailored by the addition of the PDOLLA as a compatibilizer and that the blend containing a proper content of PDOLLA had the potential to be used as a medical implant material. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41323.     

Morphology of phase separated blends of poly(cyclohexyl methacrylate) with poly(vinyl acetate)

Blends of poly(vinyl acetate) (PVAc) and poly(cyclohexyl methacrylate) (PCHMA) labeled by copolymerization with 4‐methacryloylamine‐4′‐nitrostilbene (Sb), with (1‐pyrenylmethyl)methacrylate (Py) or with 3‐(methacryloylamine)propyl‐N‐carbazole (Cbz), were prepared by casting dilute solutions in tetrahydrofurane (THF) or chloroform onto silanized glass plates. The resulting films were studied by epifluorescence microscopy, microfluorescence spectroscopy, DSC and optical microscopy. Epifluorescence micrography probes the chemical composition of the different regions in phase separated blends, with black areas corresponding to PVAc rich regions and colored areas corresponding to labeled PCHMA rich regions. The technique also visualizes primary and secondary morphologies, which depend on the composition of the polymer blend and on the casting solvent. Mixtures containing 80 wt % PCHMA show, in general, a bicontinuous primary morphology suggesting a spinodal demixing mechanism. Solvent effects are particularly relevant for 50% and 20% PCHMA samples showing morphologies composed of PCHMA rich domains, in a matrix of solvent‐dependent compositions. Samples cast from chloroform are more homogeneous and the matrix is always highly fluorescent. In contrast, the domains of samples cast from THF are heterogeneous in size and shape and the matrix is non‐fluorescent, being thus formed by nearly pure PVAc. Small voids are formed in the polymer‐air interface. They are submicrometric for THF cast films and disappear with annealing at 122°C. For chloroform cast samples they are much less frequent and appear well ordered, forming a mostly hexatic two dimensional network. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1284–1290, 2003     

Miscibility in poly(vinyl chloride)/chlorinated poly(vinyl chloride) blends,and blends of different chlorinated poly(vinyl chlorides)

Blends of poly(vinyl chloride) with chlorinated poly(vinyl chloride) (PVC), and blends of different chlorinated poly(vinyl chlorides) (CPVC) provide an opportunity to examine systematically the effect that small changes in chemical structure have on polymer-polymer miscibility. Phase diagrams of PVC/CPVC blends have been determined for CPVC's containing 62 to 38 percent chlorine. The characteristics of binary blends of CPVC's of different chlorine contents have also been examined using differential calorimetry (DSC) and transmission electron microscopy. Their mutual solubility has been found to be very sensitive to their differences in mole percent CCl₂ groups and degree of chlorination. In metastable binary blends of CPVC's possessing single glass transition temperatures (T_g) the rate of phase separation, as followed by DSC, was found to be relatively slow at temperatures 45 to 65° above the T_g of the blend.     

Impact-modified poly(styrene-co-acrylonitrile) blends containing both oxazoline-functionalized poly(ethene-co-1-octene) elastomers and poly(styrene-co-maleic anhydride) as compatibilizer

Blends of a poly(styrene-co-acrylonitrile) (SAN) with poly(ethene-co-1-octene) rubber (EOR) were investigated. An improved toughness–stiffness balance was obtained when adding as a compatibilizer a blend consisting of oxazoline-functionalized EOR, prepared by grafting EOR with oxazoline-functional maleinate, and poly(styrene-co-maleic anhydride) (SMA), which is miscible with SAN. Enhanced interfacial adhesion was evidenced by the improved dispersion of the EOR in the SAN matrix and the reduced glass transition temperature of the dispersed EOR phase. Morphology studies using transmission electron microscopy revealed formation of an interphase between the matrix and the rubber particles. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 73: 1685–1695, 1999     

Sequence analysis and fiber properties of a blend of poly(ethylene terephthalate) and poly(ethylene terephthalate‐co‐4,4′‐bibenzoate)

Blends of poly(ethylene terephthalate) (PET) and poly(ethylene terephthalate‐co‐4,4′‐ bibenzoate) (PETBB) are prepared by coextrusion. Analysis by ¹³C‐NMR spectroscopy shows that little transesterification occurs during the blending process. Additional heat treatment of the blend leads to more transesterification and a corresponding increase in the degree of randomness, R. Analysis by differential scanning calorimetry shows that the as‐extruded blend is semicrystalline, unlike PETBB15, a random copolymer with the same composition as the non‐ random blend. Additional heat treatment of the blend leads to a decrease in the melting point, T_m, and an increase in glass transition temperature, T_g. The T_m and T_g of the blend reach minimum and maximum values, respectively, after 15 min at 270°C, at which point the blend has not been fully randomized. The blend has a lower crystallization rate than PET and PETBB55 (a copolymer containing 55 mol % bibenzoate). The PET/PETBB55 (70/30 w/w) blend shows a secondary endothermic peak at 15°C above an isothermal crystallization temperature. The secondary peak was confirmed to be the melting of small and/or imperfect crystals resulting from secondary crystallization. The blend exhibits the crystal structure of PET. Tensile properties of the fibers prepared from the blend are comparable to those of PET fiber, whereas PETBB55 fibers display higher performance. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 1793–1803, 2004     

Toughened poly(butylene terephthalate)s and blends prepared by simultaneous chain extension,interfacial coupling,and dynamic vulcanization using oxazoline intermediates

Toughness of poly(butylene terephthalate) (PBT) was improved by reactive blending of PBT with 2-substituted 1,3-oxazoline intermediates such as low-molecular-weight bisoxazolines, and oxazoline-functionalized nitrile rubbers derived from both nitrile liquid rubber (Nipol®) and high-molecular-weight hydrogenated nitrile rubber (Therban®). Conversion of 7 mol % of the nitrile groups of Nipol into 1,3-oxazoline, corresponding to less than 1 oxazoline group per chain, was sufficient to afford melt strengthening and substantially improved dispersion and interfacial adhesion of the nitrile rubber microphases in the PBT continuous phase. Also in the case of high molecular weight Therban, oxazoline functionalization significantly improved compatibility with PBT. Best results in terms of toughness/stiffness balance, with impact strength exceeding 200 kJ/m², was achieved when PBT was blended with both oxazoline-functionalized high-molecular-weight hydrogenated nitrile rubber and low-molecular-weight bisoxazoline chain extenders. The outstanding performance of such PBT blends, containing 10 and 20 wt % oxazoline-modified Therban and 0.6–1.1 wt % bisoxaoline chain extender, respectively, was attributed to simultaneous bisoxazoline-mediated PBT chain extension, interfacial coupling and dynamic vulcanization of the oxazoline-functionalized nitrile rubber. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 66: 633–642, 1997     

Porous poly(L‐lactic acid)/poly(ethylene glycol) blend films

Poly(L ‐lactic acid) (PLLA: M_w = 19.4 × 10⁴)/poly(ethylene glycol) (PEG: M_w = 400) blend films were formed by use of a solvent‐cast technique. The properties and structures of these blend films were investigated. The Young's modulus of the PLLA decreased from 1220 to 417 MPa with the addition of PEG 5 wt %, but the elongation at break increased from 19 to 126%. The melting point of PLLA linearly decreased with increases in the PEG content (i.e., pure PLLA: 172.5°C, PLLA/PEG = 60/40 wt %: 159.6°C). The PEG 20 wt % blend film had a porous structure. The pore diameter was 3–5 μm. The alkali hydrolysis rate of this blend film was accelerated due to its porous structure. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 965–970, 2004