Temperature network

The constant-temperature network partition function Q under a given deformation, specified by the deformation ratios %x, Xy and A, is obtained by assuming that there are no interactions between the chains other than those imposed by the presence of volume-less crosslinks. 

Polymers with longer side-chains (Ciq and Cjs) exhibit non-Newtonian viscosity at room temperature, and the viscosity decreases with increasing shear rate. Because the side-chain T s for and C s polymers are above room temperature, network formation via intermolecular crystallization of the paraffinic side-chains is believed to be responsible for the unusually high... 

Recent Advances in High-Temperature Network Polymers of Carboranylenesiloxanes and Silarylene-Siloxanes... 

In weak association for pairwise association (k = 2), most helices are short and unassociated at high temperatures. Helices grow and association starts to take place near the coil-helix transition temperature. The elastic modulus of the network in this region is not related to the total helix content. Pair formation is sharply enhanced around the transition temperature, and paired helices dominate below this temperature. Networks formed around this temperature are basically type II in which short unassociated helices (20% of the total length) are connected by long paired helices (70% of the total length) at junctions via short random coils. At lower temperatures, the helices condense into long paired ones the system becomes a concentrated solution of rod-like molecules of helix pairs. 

With the rise of the temperature, networks are formed in a stage where there is a three-dimensional evolution. This change is a reflection of molecular mass increase, the appearance of gelled structures and entanglements between polymer chains (Figure 1.5). 

Figure 8.5 Effect of glass composition on the network breakdown in glass fibres exposed to cement extract solutions at various temperatures. Network breakdown was calculated by summing up the network formers removed from the glass, as reported by Lamer et al. [ 16] (after Majumdar [17]).

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