Organic polymer solidification

Major categories of industrial waste solidiflcation/stabilization systems are cement-based processes, pozzolanic processes (not including cement), thermoplastic techniques, organic polymer techniques, surface encapsulation techniques, and self-cementing techniques (for high calcium sulfate sludges). Vitrification (discussed previously) can also be considered a solidification process. 

Solidification with thermoplastic materials Solidification with organic polymers Encapsulation... 

Methods of solidification with organic polymers involve the addition and thorough mixing of monomers, such as urea and formaldehyde, with the wastes. A polymerization catalyst can be added. The mixtures can be placed in... 

Solidification. In principle, any solid that contains firmly bound water may be suitable as a solidification form for HTO. This includes drying agents, such as silica gel, molecular sieves, and calcium sulfate, as well as hydraulic cement and organic polymers. Most experience is available with cement, which has been used to solidify non-high-level waste for quite a while. 

It was first clearly shown by Bartenev [21] that when the cooling rate is decreased, the solidification temperature of silicate glass decreases proportionally. This behaviour was confirmed for many types of silicate glass and organic polymers in subsequent papers by various authors [22] and [23]. 

The importance of some of these process issues relating to polymer solution rheology and solidification can be seen in the dry spinning of acrylics (Cox, 2005). An acrylic fiber is one in which the fiber-forming substance is any long chain synthetic polymer composed of at least 85% by weight of acrylonitrile (AN) units (-CH2-CH(CN)-). Acrylic fibers are made from the polymer polyacrylonitrile (PAN), a synthetic, semicrystalline, organic polymer... 

The formation of the microstructure involves the folding of linear segments of polymer chains in an orderly manner to form a crystalline lamellae, which tends to organize into a spherulite structure. The SCB hinder the formation of spherulite. However, the volume of spherulite/axialites increases if the branched segments participate in their formation [59]. Heterogeneity due to MW and SCB leads to segregation of PE molecules on solidification [59-65], The low MW species are accumulated in the peripheral parts of the spherulite/axialites [63]. The low-MW segregated material is brittle due to a low concentration of interlamellar tie chains [65] and... 

Crystalline lamellae are the basic units in the microstructures of solid semicrystalline polymers. The lamellae are observed to be organized into two types of larger structural features depending on the conditions of the bulk solidification process. 

This approach towards nanostructured inorganic-organic hybrid materials is the first one to allow the synthesis of inverse-topology systems, in which the hydrophobic polymer blocks represent the outside of the microphase-separated structure. After solidification of the inorganic sol, the hydrophobic phase can be swollen with organic solvents. This procedure allows the isolation of colloidal objects, such as spheres or ceramic rods (see Fig. 12), from one another, which are sterically stabilized, because the hydrophihc block is firmly anchored in the ceramic material [45]. 

The CPNC performance depends on the degree of platelets dispersion, with some properties more affected by it (e.g., mechanical, barrier) than others. The degree of dispersion is controlled by the thermodynamic miscibility between polymer and organoclay, solidification of organics on the clay platelets, and their concentration [Utracki, 2004, 2008a]. The PVT measurements and interpretation of the CPNC behavior provide a direct means of extracting information about matrix-clay... 

---