Blending mechano-chemical

Table 10 Effect of Short-Time Aging on Mechano-Chemical Properties of PVC-NBR Blend...

In contrast to the usual blending of cellulose via a solution medium, a fine-powdered composition was obtained by ball-milling a dry mixture of fibrous cellulose and granulated PEG without any solvent [63]. A certain extent of compatibilization of PEG with cellulose appears to occur even in their solid state, probably by insertion of parts of PEG molecules into the cellulose domains, followed by the formation of hydrogen bonds between cellulose hydroxyls and polyether oxygens. It was shown that such a mechano-chemically prepared powder was moldable three-dimensionally by facile hot-press treatment, e.g., at 120 °C for a composition of CELL/PEG = 80/20 (wt/wt) [64],... 

U12 Unknown reaction mixture of polymer 1 and polymer 2. Specific examples mechano-chemical blends which contain unknown proportions of grafts, blocks, and homopolymers or solution graft copolymers which contain much homopolymer. Various isomers can be formed. 

Flow may also cause mechano-chemical degradation that generates reactive components, viz., radicals, peroxides, acids, etc. Trans-esteriflcation, trans-amidation and ester-amide exchange reactions during processing are well documented (their rate depends on the total interphasial area that in turn depends on flow). These reactions may be responsible for the formation of compatibilizers that increase the interphasial area, affect the phase equilibria, and the regularity of the main chain, thus modify the degree of dispersion, blend s crystallinity, hence performance. 

Two immiscible polyolefins may both be subject to mechano-chemical radical generation during extmsion processing. In blends of POs that are not prone to degradation upon radical formation, a crosslinked copolymer may result... 

Some polymers contain reactive functionahty but are also themselves subject to mechano-chemical radical generation. When such polymers are blended under high-shear mixing with a second functionalized polymer, the architectures... 

Parts of friction joints and seals are often made from inhibited structural plastics (see Chap. 4). Their main role in metal-polymer friction joints is to abate Mechano-chemical wearing of metal counterbodies. Application of inhibited antifrictional materials is considered to be a promising trend for extending the life of friction joints operating in hostile media. The structural polymers or their blends most often contain plasticizers. Cl, fillers and modifiers as additional components. The inhibited plastics are employed in plain bearings, sealing elements and other members of oil-extracting equipment and vehicles. 

The first attempt was aimed to synthesize the different UHTCs by SHS according to reactions (l)-(6), when starting from simply blended powder mixtures. While the ZrB - and HfB -based systems were found to clearly exhibit a self-propagating behaviour, both TS and TTS compositions did not. This fact could be readily explained on the basis of the relatively lower heat of reactions (3) and (6) (cf. Table 3). Thus, the mechano-chemical activation of the related starting reactants under the conditions reported in the experimental section was required to induce the SHS character in the synthesis reactions. 

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