Ohio 44106 synopsis Poly(bismethy1ene hydroquinone) (PBHQ) has been synthesized. Fourier transform infrared, l3C solid-state -/MAS NMR and elemental analysis provide strong evidence of two methylene ( A H , \ ) bridgea per hydroquinone molecule. The polymer waa (1) air oxidized using ammonia and (2) chemically oxidized using bromine/KOH. The initial structure and oxidation process was studied by comparison of the unoxidized and oxidized polymers using Fourier transform infrared, elemental analysis, and '3c solid-state CP/MAS NMR. 2660 DALAL, LITI', AND RICKERT The Andrew-Beam type spinners were constructed from polyoxymethylene (Delrin), and were spun with a speed in the range of 3.5 KHz. The resolution of Delrin (89 ppm) was used as a reference.The elemental analysis on dried samples were done by the Galbraith Laboratories, Knoxville, TN. Synthesis of Poly(bismethy1ene Hydroquinone) (PBHQ)5.5 g (0.061 moll of trioxane and 10.0 g m s (0.091 moll of hydroquinone were placed in a pressure vessel. 0.1 gm of toluene sulphonic acid, 70 cc of sulfolane and 30 cc of distilled water were added. The pressure vessel was closed; vacuum was applied for 5 min and the vessel was sealed under vacuum. The reaction was carried out at 175°C for 1 h in a silicone oil bath. The pressure vessel was cooled overnight, the product was removed and boiled for 15 min with 1000 cc of water three times to remove sulfolane. The product was filtered and dried in a vacuum oven for 24 h at 120°C. 11.5 gms of black product was obtained. The dried product was characterized by Fourier transform infrared, '3c solid-state CP/MAS NMR, and elemental analysis.
Stress‐strain relationship of 2,6 dimethyl poly(phenylene oxide)(2,6 MPPO) was established simultaneously with optical micrographic examination as a function of thermal history. Films (5–7 μm) were solvent cast and annealed below their glass transition and melting point. As‐cast film showed ductile behavior associated with shearband formation, whereas thermally treated material exhibited marked embrittlement; the slower it cooled the more brittle it became. Thermally treated material showed mixed mode deformation: crazing and shearbanding. The correlation between the deformation mechanism and its solid state structure was studied using differential scanning calorimetry, wide angle x‐ray diffraction, and density measurement.
Soluble poly(bismethylene hydroquinone) (PBHQ) of two different intrinsic viscosities and degrees of ring closure were synthesized. The polymers were chemically oxidized using bromine. The oxidation process was studied by comparison of the unoxidized and oxidized polymers using Fourier transform infrared, 13C solid-state CP/MAS NMR, elemental analysis, UV spectroscopy, and electron spin resonance. The oxidation-reduction processes of the polymers were studied using cyclic voltammetry.Polymeric quinones have attracted study because of their ability to behave as oxidationrreduction systems (1-5). These polymers have also been reported for applications such as reagents for separation and identification of metals (6) and as anti-ulcer agents (7). Hunt and Lindsey and other workers (8-10) have made a detailed study of very low molecular' weight quinone systems with single methylene bridges between the quinone molecules. In our previous work (11), we have described the synthesis, structural characterization, and oxidation of a cross-linked bismethylene polymer.However, little is known about the chemical and electrochemical behavior of bimethylene polymers. This work describes the synthesis, oxidation, and electrochemical behavior of soluble poly(bismethylene hydroquinone). ExperimentalFourier transform infrared spectroscopy.--Infrared spectra were obtained on a Digilab Model FTS-14 Fourier transform spectrophotometer at a resolution of 8 cm -1 with a total of 10 scans and stored in the system's memory for further data manipulation. The frequency scale is calibrated internally to an accuracy of 0.2 cm -1. The weights of all the sample in KBr powder were kept constant for comparison purposes (2 mg in 200 mg KBr). In order to ensure complete removal of water, the pellets were dried in a vacuum oven at 120~ over a period of time, until the spectra no longer changed.13C solid-state CP/MAS NMR.--The ~3C solid-state CP/MAS NMR spectra were recorded at 37.7 MHz with a modified Nicolet NT-150 spectrometer equipped with a cross-polarization accessory. Radio frequency amplifiers delivering 550W at 150 MHz, and 1000W at 37.7 MHz were adjusted to satisfy Hartman-Hahn conditions at approximately 64 kHz (12). In all cross-polarization experiments, the contact time was 1 ms, and the delay between successive pulses was 2s.The Andrew-Beam type spinners were constructed from po]yoxymethylene (Delrin) and were spun with a speed in the range of 3.5 kHz. The Delrin peak (89 ppm) was used as a reference.Elemental analysis.--Elemental analyses on dried samples were done by the Galbraith Laboratories, Knoxville, Tennessee.Synthesis of tetramethylol hydroquinone (TMHQ).--2,3,5,6-Tetramethylol hydroquinone was synthesized using the method of Euler et al. (13).
Although thermoplastic extrusion and injection molding have been extensively studied by a large number of authors, very little is known about the correlations between the extrusion and injection molding process variables. This paper describes the various comparable process variables between extrusion and injection molding of PVC dry blends. The Brabender extruder of 19 mm diameter and 25:l length to diameter ratio and the Szekeley reciprocating single screw injection molding machine were used. PVC dry blends of industrial importance were prepared using a high speed mixer. The four mix formulations based on a commercial grade of PVC were used. Process variables studied during the injection molding were the melt temperature near the nozzle, injection pressure, injection speed, and energy consumption. Process variables studied during extrusion were the melt pressure at the die, power consumption, and the melt temperature at the die orifice. The correlations between the extrusion and injection molding process variables for PVC dry blends have been established.
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