Example calculations swelling data

Example Calculation of Young s Modulus from Swelling Data... 

These equations allow either to predict the swelling degree (w = l/(p) as a function of external conditions or to calculate the network parameters from the correlation between the theoretical and experimental dependencies w(q) or w(p) [22, 102], An example of such a correlation is given in Fig. 2 and 5. As can be seen, theoretical predictions are in good agreement with experimental data. However, when the outer solution contains multivalent cations, only a semi-quantitative agreement is attained. 

The second example considers a blend formed by LDPE, with 30% crystallinity, and PVC. The polymer matrices examined are pure LDPE, the blends LDPE (80%)-PVC (20%) and LDPE (50%)-PVC (50%), and pure PVC, with toluene as the penetrant. Experimental data by Markevich etalS report solubiUty of toluene in the above blends, at the temperature of 30° C, while toluene solubiUty in pure PVC was taken from Berenst l The glassy transition temperature is equal to —25° C for LDPE and to +75° C for pure PVC. Therefore, pure PVC is a glass at 30° C however, due to the large swelling and plasticization of the polymer induced by toluene sorption, it can be seen that the sorption of toluene lowers the glass transition of PVC to temperatures below 30° C, already at relatively low toluene activities. That is also confirmed by the sorption isotherm which is concave to the concentration axis as is typical of rubbery polymers. The glass transition temperatures for the blends are estimated to be — 10°C for the 80% LDPE blend and +17° C for the 50% LDPE blend, all below the temperature of the sorption experiment. The crystalline fraction of LDPE is assumed, as is usual, not to contribute to the sorption process, therefore we consider only the amorphous fraction of LDPE in the sorption calculations based on EoS. For the sake of simplicity, we present here only the results obtained with the LF equilibrium model. 

As a further example of the applicability of the NET-GP results, we consider the solubility of CO2 in PMMA at 33° C and in Teflon AF1600 (poly[2,2-bistrifluoromethyl-4,5-difluoro-l,3-dioxole(87%)-co-tetrafluoroethylene]) at 35°C[ . For both systems, the polymer dilation data are available from independent experimental measurements, enabling us to calculate the value A s. exp of the experimental swelling coefficient. The swelling coefficient has also been estimated from the solubility data by... 

Hence the experimentally determined equality of concentrations of SL components in the swollen gel and in the liquid phase allows one to predict composition of liquid, whereby polymer swelling is at its maxumun, and the preferential sorption of components of SL. To refine dependencies of ( ), on (pj or < )2 on q>2, correction can be used, for example, minimization of the square-law deviation of calculated and experimental data on the total... 

Metal coupon data are relatively easy to use for materials selection purposes from calculation of corrosion rate and observations on the appearance of the coupon. For nonme-tallic materials, the problem is to define what constitutes failure. For example, when is color change, flaking, swelling, or tackiness acceptable, and when do they indicate potential failure ... 

In this section we first will describe the experimental device. Sect. 3.2, then provide formulas to calculate m and V of a polymer sample from measured data Sect 3.3, and finally present an example namely sorption of CO2 in (swelling) polycarbonate (Makrolon 2400), Sect 3.4. 

Of the characteristics of the Mackian elasticity, the first difference of the normal stresses (N ) is usually measured and the hyperelastic deformation is calculated. The coefficient of the first difference of normal stresses /(0) for rigid macromolecules is correlated with M by the following relation /(0) -[99], which is confirmed by the experimental data on the example of 1.8-5.4% solutions of PPTA [100]. The elastic deformation is higher for solutions of PPTA than for solutions of polyamide 6.6 [101], but swelling of the extrudate (jet) is lower for them. There are also relatively narrow ranges of y in which the values of swelling are very low (=1.15). In addition, different types of instability in capillary flow arise extremely easily for solutions of rigid chains. 

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