Automation of the Rheovibron

Kenyon, A. S.; Grote, Walter; Wallace, D. A.; Rayford, McC. J.

doi:10.1080/00222347708212209

Cited by 13 publications

(4 citation statements)

References 2 publications

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“…The viscoelastomer was semiautomated (via a H P 9825 programmable calculator) as per the method of Kenyon et a1. 16 Gel permeation chromatograms of the solute portion of the irradiated blends were obtained on a Waters chromatograph (model 2442) using p-Styragel columns with tetrahydrofuran as solvent. Figure 2 shows the formation of gel as a function of dose for the range of irradiation temperatures.…”

Section: Methodsmentioning

confidence: 99%

The radiation crosslinking of poly(vinyl chloride) with trimethylolpropane trimethacrylate. I. Dose dependence and the effects of thermal treatment

Bowmer¹,

Davis²,

Kwei³

et al. 1981

J of Applied Polymer Sci

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SynopsisThe radiation crosslinking of poly(viny1 chloride), PVC, with trimethylolpropane trimethacrylate, TMPTMA, has been examined. The polyfunctional TMPTMA undergoes rapid polymerization incorporating the PVC into a three-dimensional ne work. The kinetics and mechanism of these treatment. The gel was rapidly formed with a TMPTMA polymerization rate greater than that of the PVC grafting reaction. Only 3040% of the available bonds were used in the initial polymerization. The remaining 60-70% of the double bonds predominantly react in the final stages of crosslinking (80-100% gelation). The macroscopic properties (e.g., solubility, glass transition temperatures, mechanical characteristics, etc.) of the PVC-TMPTMA blend are discussed in terms of the molecular crosslinking mechanism. The effect of thermal treatment, during and after irradiation. on the reaction rates and mechanism is examined.crosslinking reactions were studied with particu > ar reference to dose dependence and thermal

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Section: Methodsmentioning

confidence: 99%

The radiation crosslinking of poly(vinyl chloride) with trimethylolpropane trimethacrylate. I. Dose dependence and the effects of thermal treatment

Bowmer¹,

Davis²,

Kwei³

et al. 1981

J of Applied Polymer Sci

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“…Gains in accuracy, simplicity of operation, and adaptability to digital process ing of the data were reported. The Rheovibron itself has been auto mated by the manufacturer (3) and the Rheovibron DDV-II was also automated (6) to provide automatic control of tension, increased sen sitivity, and calculation and printout of Ε ', Ε", and tan δ. The latter unit has been commercialized (Imass, Inc.) (4) as the Autovibron, model DDV-II-C.…”

Section: Inmentioning

confidence: 99%

Dynamic Mechanical Spectroscopy Using the Autovibron DDV-III-C

Webler

Manson

Lang

1983

Advances in Chemistry

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This-document has been approved for public release; its distribution is unlimited. The Autovibron DDV-IIIC (IMASS, Inc.) is a forded vibration unit capable of operating at several constant frequencies for the determination of the dynamic mechanical response of a system. The automation provides a programmed heatine rate, continuous sample tensioning, and acquisition and reduction of data. Recently a generally similar adaptation has been introduced, based on the hydraulically operated Rheovibron DDV-III-C. Automation of a resonance-type (7) and a different constant frequency instrument(8) have also been described. DISTRIBUTION STATEMENT (of the abstract enteredWhile a full critical analysis of the operation of the Autovibron DDV-III-C has not yet been possible, it is appropriate to describe our experience with this new instrument, and to make preliminary recommendations with respect to operation and future improvement. Since the instrument is the first of its type, the observations reported should be helpful to other investigators. Results obtained in our laboratory using an automated DDV-II are also described for comparison. Temperature programming is effected through the calculator in conjunction with a platinum resistance thermometer. From -140 0 C to -45 0 C the temperature is allowed to increase without regulation at a rate of ,I*C/ min. At -45 0 C, power is supplied to the heaters and the temperature is controlled by programming the application of power. The temperature use can also be controlled at rates other than 1C/min. through changes in the operating program. For temperatures above 175 0 C, the high-temperature chamber must be used.Phase-angle measurements using the lock-in analyzer were incorporated to simplify automation of the measurements, improve resolution of small angles, and increase the range of tan 6 measurements (4). The calculator alternately switches the load (P) and displacement X) signal through the multiprogramler to the lock-in analyzer. After a programmed delay for setting of the signal, the in-phase and quadrature components of the respective signals are measured with respect to a reference signal from th= Autovibron. The complex Young's modulus, E*, is calculated using Equaticn 1. •With E* and 6 from Equations I and 2, respectively, the storage modulus, E', and loss modulus, E", can be calculated.E' =IE*/cos 6 (3)E" -/E*/sin 6 (4)The data acquired are displayed while the program is running and stored on magnetic-tape cartridges for further reduction. Results can be printed or plotted during the run with appropriate programming; programs for data reduction and plotting from tape are available. EXPERIMENTALProblems and their correction. During start-up and subsequent trials using the DDV-III-C, several significant problems have been encountered.Much of our recent work has been conducted using an automated DDV-II because of problems with the DDV-III. Preliminary work with the large load capacity unit has shown problems in sample tensioning, load control, measurement of small phase ang...

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“…Data on other pairs of transitions and/or other polymers may give different results. Also, the automated Rheovibron is said to have better resolving power than the older models(20).…”

mentioning

confidence: 99%

Automated Dynamic Mechanical Testing

Boyer

1983

Advances in Chemistry

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During the past 10 years a number of fully automated instruments for the dynamic mechanical testing of polymers became commercially available. Our purpose is to provide an introductory survey that covers key references, the goals of such test methods, general but not specific differences between the several types of instruments, and factors to consider in choosing an instrument. These latter topics include fixed vs. variable (resonant) frequency, frequency range, resolving power, types of specimens that can be handled, and maintenance costs. We also emphasize that all suppliers and users of such instruments are striving to improve and/or extend the range of capabilities of their respective instruments. A special section discusses the problem of determining activation enthalpies for any loss process. Finally, we point out that parallel developments are occurring in dielectric testing via new techniques: automated self-balancing dielectric bridges, and new methods of treating dielectric data. Thermally stimulated creep and thermally stimulated current are relatively new methods. We consider these alternate techniques as both competitive with, and complementary to, dynamic mechanical methods. Possible artifacts introduced by the use of porous substrates to support fluid polymers are discussed and dismissed.^JENERAL ASPECTS OF DYNAMIC MECHANICAL and dielectric testing, automated or not, are discussed in this chapter. Background material is given in References 1-10. For many years I collected transition and relaxation temperature data from the literature, whether obtained by static methods such as thermal expansion or by dynamic methods including both mechanical and dielectric loss. This endeavor pro-0065-2393/83/0203-0003$06.75/0

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Automation of the Rheovibron

Cited by 13 publications

References 2 publications

The radiation crosslinking of poly(vinyl chloride) with trimethylolpropane trimethacrylate. I. Dose dependence and the effects of thermal treatment

The radiation crosslinking of poly(vinyl chloride) with trimethylolpropane trimethacrylate. I. Dose dependence and the effects of thermal treatment

Dynamic Mechanical Spectroscopy Using the Autovibron DDV-III-C

Automated Dynamic Mechanical Testing

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