Plasticising effect

Its plasticising effect on some polymers which increases segmental mobility and enhances the value of the dielectric constant of the polymer itself. 

The absorbed water has a plasticising effect and thus will cause a reduction in tensile strength and modulus, and an increase in impact strength. As has already been mentioned the presence of absorbed water also results in a deterioration of electrical properties. 

The rather unexpected plasticising effect of camphor was first appreciated by Hyatt over a hundred years ago and, in spite of all that has been learned about polymers since then, no superior plasticiser has yet been discovered. 

Mastication which is carried out at temperatures exceeding 115 °C. In hot mastication, the plasticising effect results from oxidative reactions. See Cold Mastication. 

Polyglycols or polyglycol ethers, which have gas absorption properties and exhibit a plasticising effect in... 

STUDY OF PLASTICISATION EFFECTS IN POLY(VINYL CHLORIDE)... 

The volumetric, elastic and dynamic properties of internally and externally plasticised PVC were studied and compared with those of unplasticised PVC. The glass transition temperature for the plasticised samples was markedly lowered and this decrease was more important for the externally plasticised ones. The positions of the loss peaks from dielectric alpha-relaxation measurements confirmed the higher efficiency of the external plasticisation. However, the shape of the dielectric alpha-relaxation function was altered only for the internally plasticised samples. The plasticisation effect was linked with a decrease in the intensity of the beta-relaxation process but no important changes in the activation energy of this process were observed. The results were discussed. 47 refs. 

Fig. 3.11 The plasticising effect of diphenyl in poly(vinylchloride) dielectric loss curves at 60 Hz for (right to left) 0, 1, 3, 6, 9, 12, 15, 20% diphenyl. Reproduced from Fuoss (1941). Copyright of the American Chemical Society.

The development of highly crosslinked rigid polyisocyanurate foams opens an excellent area of applications for polyester polyols [4-8]. The required polyols do not need high functionality and the plasticising effect of polyester structures is extremely beneficial for these highly crosslinked systems [6]. The first polyester polyols used for these applications were low viscosity polycondensation products of AA with ethyleneglycol (EG) or diethyleneglycol modified with phthalic anhydride or triols. 

One typical composition for a blood bag is 59 wt.% PVC, 12% Vitamin E, 6% citrate plasticiser, 14% TEHTM and 9% epoxidised soya oil. Vitamin E suppresses haemolysis of red blood cells, while the soya oil is a thermal stabiliser for PVC processing which also has some plasticising effect. Thus, plasticised PVC can act as a reservoir for additives of a preservative nature. 

In addition to applying excessively high processing temperatures, the presence of residual catalysts can induce depolymerisation. When monomer is formed during processing, it can act as a plasticiser, effectively altering the materials thermal and mechanical properties. 

Plasticiser Effect on Calcium Carbonate Filled Poiysuifide Composition (Cast sheets cured 7 daysat 70-72"F and 44-48% Relative Humidity)... 

The good flow properties of these alloys have made them ideal for a wide range of injection moulding applications, such as thin-wall articles, within the E E and TT sectors. Until the last few years, these very properties, including the plasticising effect of the FRs used, prevented adequate melt stability from being achieved and so precluded their use in extrusion. 

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