Fracture liquid polymer

Table I shows the fracture energies for epoxy resin which have been toughened by liquid polymers with different functional groups. Clearly the selectivity of the functional groups is more important than the reactivity. MTBN, with the most reactive mercaptan end groups, had the least improvement in fracture energy the cured material is trans-...

Effect of Molecular Structure. Table III shows the effects of the molecular structure of the liquid polymer on the fracture energy of toughened systems. The CTIN is a carboxyl terminated isoprene-acrylonitrile copolymer CTBS is a carboxyl terminated butadiene and styrene copolymer, and CTA is a copolymer of ethyl acrylate-butyl acrylate. 

Table III. Effect of Molecular Structure of Liquid Polymers on Fracture Energy of Epoxy Resin0...

Structured laundry liquids are currently available in Europe and were recently introduced in the United States [50,51]. These products typically contain high levels of surfactants and builder salts, as well as enzymes and other additives. In the presence of high ionic strength, the combination of certain anionic and nonionic surfactants form lamellar liquid crystals. Under the microscope (electron microscope, freeze fracturing) these appear as round droplets with an onion-like, multilayered structure. Formation of these droplets or sperulites permits the incorporation of high levels of surfactants and builders in a pourable liquid form. Stability of the dispersion is enhanced by the addition of polymers that absorb onto the droplet surface to reduce aggregation. 

The most frequently quoted example to illustrate this behaviour is the children s toy Silly Putty , which is a poly(dimethyl siloxane) polymer. Pulled rapidly it shows brittle fracture like any solid but if pulled slowly it flows as a liquid. The relaxation time for this material is 1 s. After t = 5t the stress will have fallen to 0.7% of its initial value so the material will have effectively forgotten its original shape. That is, one could describe it as having a memory of around 5 s (about that of a mackerel ). Many other materials in common use have relaxation times within an order of magnitude or so of 1 s. Examples are thickened detergents, personal care products and latex paints. This is of course no coincidence, and this timescale is frequently deliberately chosen by formulation adjustments. The reason is that it is in the middle of our,... 

Tensile-fractured as-spun fibers of /Bu-HQ/Cl-PEC and Ph-HQ/Cl-PEC no longer exhibited fibrils, with such phenomena being different to those of the fBu-HQ/PEC and Ph-HQ/PEC systems. Thus, in order to obtain high-modulus as-spun fibers, the stability of the liquid crystalline state and the rigidity of the polymer chain are both assumed to be influential factors. 

CARS microscopy has emerged as a highly sensitive analytical tool for vibrational bioimaging, predominantly, of lipids in membrane model systems [69, 81-84], live unstained cells [85-95, 43], and both ex vivo and in vivo tissues [26, 96-103, 43]. Examples of CARS imaging applications in the physical and material sciences include the study of fracture dynamics in drying silica nanoparticle suspensions [104], patterned polymeric photoresist film [105], drug molecules in a polymer matrix [106], and liquid crystals [107, 108],... 

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