C for Polymers

TABLE 10.5 Gas Permeability Constants (10 P) at 25°C for Polymers and Rubbers The gas permeability constant P is defined as... 

TABLE 10.6 Vapor Permeability Constants (1010P) at 35°C for Polymers... 

Table 15 Limited oxygen index (LOI) values at 20 °C for polymers...

Carbazole-containing PODs have been obtained (53) by cyclodehydration (in the presence of POCl3) of polyhydrazides prepared by polycondensation of IV-ethyl-3,6-carbaZoledicarbonyl chloride with dihydrazides of the corresponding dicarboxylic acids. Thermal decomposition of the polymers containing aliphatic units occurs at 365-380°C, compared to 400-405°C for polymers containing aromatic units. 

TABLE 10.7 Vapor Permeability Constants (1010P) at 35°C for Polymers All tabulated values are multiplied by 1010 and are in units of seconds-1 (centimeters of Hg)-1. 

Figure 29.5 shows the effects of the LiTFSI concentration on the ionic conductivities at 30°C for polymers El and IV. Although the ionic conductivity of polymer III was very poor in bulk, it unproved considerably with the increasing LiTFSI concentration. When the LiTFSI concentration was 100mol% to the imidazolium... 

Effects of Concentration. In Figure 11 apparent viscosity is plotted as a function of concentration for each of the terpolymers at low shear in water. For those terpolymers with relatively high molar concentrations of monomer pairs in the feed, significant enhancement in viscosity is observed beyond C. For polymers with less than 5 mol % of each comonomer, little viscosity enhancement is observed over the entire concentration range as compared to homopolyacrylamide of similar molecular weight. 

Table 36-8. Structure and Properties of Some Unfilled Fluorine-Containing Thermoplasts at about 23 C. For Polymers, the Abbreviated Name, the Chemical Nature of the Monomeric Unit, and, for Copolymers, the Types of... 

Figure 2.8 Plots of n/c versus c for polymers of different molecular weight (M1-M4) are illustrated. Extrapolation to infinite dilution makes it possible to calculate the number average molecular weight ab initio (i.e. no calibration is required). The slope of each of these lines gives values for the second virial coefficient.

Table 11.19 Limited Oxygen Index (LOI) Values at 20°C for Polymers"...

Last but not least, Meier and Mutlu reported on the synthesis of various ester-functionalised norbornenes using fatty acids of different chain lengths (C6 to Cl 8) [62]. Their ROMP led to polymers with Mn values <165 kDa. Some properties of these materials were dependent upon the chain length of the fatty acid used to prepare them. For instance, the Tg decreased from 102 to -32 °C for polymers based on fatty acids with a chain length of 6-18 carbons, and the T decreased from 30 to 6 "C with the same increase in chain length [16]. 

The copolymers obtained are true copolymers and not a mixture of two homopolymers. This is indicated by the presence of a single glass transition temperature. For example, glass transition temperatures of polystyrene and poly(methylmethacrylate) are 100 and 114 °C. Single glass transition temperatures at 112 °C for polymer 19 (about 43% of cyclophosphazene) and 151 °C for polymer 20 (about 40% of cyclophosphazene) were detected. 

Samples were prepared, stretched, and irradiated as previously described. The temperature of stretching, transportation to the cobalt source, and irradiation were 0, -15, and -15 C for Polymer B, and 0, -15, and -lO C for Polymer C, respectively. In the stretching procedure at 0 u, the chosen elongation was reached in about 30 sec and the sample was quenched to -15 C for exactly 3 min after the stretch was begun, so the extent of entanglement relaxation was carefully controlled. Meanwhile the sample was attached to a steel band on which it remained during irradiation, so its length in the strained state could be measured accurately. 

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