Die spezifische Wärme des Polyvinylchlorids

The Annealing of Crystals

“…VI1.7 for polystyrene glasses which were produced with increasing internal stresses by cooling under increasing hydrostatic pressures (Weitz and Wunderlich, 1974). Similar behavior is observed on heating of drawn glassy polymeric samples (Tautz et al, 1964;Grewer and Wilski, 1968;Park and Uhlmann, 1973). Figure VI1.8 shows that on annealing at 70°C, the lower limit of the glass transition region, the more stable state achieved by slow cooling at atmos pheric pressure is reached finally.…”

Microcrystalline and three-dimensional network structure of plasticized poly(vinyl chloride)

“…The calculated values of degree of crystallinity of table 1 and subsequent tables were obtained by comparison with the value of AH ° = 10.5 + 1.0 cal/g in this work, which compares favorably to the values of 10.5 cal/g determined by Anagnostopoulos et al [37] and 12.0 cal/g determined by Juijn et al [30]. Other values of AH ° have been reported by Grewer and Wilski [27,28].…”

Heat capacities of linear high polymers

“…Other adiabatic calorimeters used for polymer heat capacity measurements have been described by Popov and Kolesov (1956); Warfield, Petree, and Donovan (1959); Heltwege, Knappe, and Wetzel (t962); Burdzhanadze, Privalov, and Tarvkhelidze (t963); N61ting (19S3) ; Hager (1964); Braun, Helhvege, and Knappe (1967); and Grewer and Wilski (1968).…”

“…Only data by Lebedev, Rabinovich, and Budarina (1967) cover the larger region 60--300 ° K. Also, agreement between data is not very good because most commercial samples contain stabilizer and plasticizer. Grewer and Wilski (1968) show additional maxima and minima in the heat capacity curve for quenched and/or drawn material. Badoche andLi (1950 and1951) have measured the heat capacity as a function of molecular weight and find a decrease for larger molecular weight.…”

“…Bekkedahl and Scott (1942) measured the heat capacity of a single butadiene-acrylonitril copolymer (Hycar OR-15). Grewer and Wilski (1968) published heat capacity data for a copolymer of 85% vinyl chloride and 15% vinyl acetate. More information is necessary for a discussion of these additional copolymer systems.…”