Thermal processing solubility

Research activities in the area of PODs containing aromatic groups have been centered around the production of highly processible, soluble, and thermally stable polymers. In this particular class of PODs, the imide-and phenylene-containing backbones have been widely explored. 

The standard California tests6 for solubility in strong and weak acids were performed on samples of the unmixed wastes and waste/additive mixtures, both before and after thermal processing. Analytical testing was performed by a state-certified laboratory, and results were compared to California TTLC (strong acid) and... 

Table 2 presents concentrations of soluble metals in the three types of samples. Unfired sludge and sludge/additive mixture samples were dried, and all the samples were pulverized to a fine powder prior to analysis. Thermal processing of the samples described in Table 2 was performed in a laboratory muffle furnace. 

Hard fats are used to coat water-soluble bioactives. Release occurs by heating above the melting point of the fat or by mechanical rupture. Fat coatings have been used for protecting many water-soluble materials, which may otherwise be volatilized or damaged during thermal processing and to deliver materials such as ferrous sulfate, vitamins and other minerals. The peptides of casein hydrolysates encapsulated in lipospheres were shown to have reduced bitterness (Barbosa et al. 2004). 

Generally, two ways have been pursued to overcome these drawbacks. The first is to suppress the strong interchain interactions which cause the poor solubility and processibility [16]. These interchain interactions are drastically reduced when the distance between the polymeric backbones is increased, for instance via the introduction of bulky side-groups. The second possibility is to separate the formation of the first and second chain of the double-stranded polymer, and to process the materials at the stage of the soluble single-stranded intermediates. These precursors can be converted into the (insoluble) ladder polymers during the final step that is a favored thermal process carried out in the solid state. 

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