High shear mechanical treatment

Homogenization has also been applied to various types of primary wall cellulose (e.g. sugar beet, potato tuber, banana rachis) where the microfibrils are more loosely organized than in the secondary wall of wood cells [28-31]. Hence, the disintegration requires less energy and the fibers are more easily delaminated. However, the material still mainly consists of bundles of microfibrils. 

On the other hand, by combination of high shear with chemical pretreatment, MFC with well-controlled diameter may be produced at reduced energy consumption. 

This mild hydrolysis retained the high aspect ratio of the fibrils, giving a highly entangled gel-network in aqueous suspension. Another method was presented by Saito and coworkers [33], who used TEMPO-mediated oxidation (Section 8.5.4.1) of never-dried pulp before homogenization. This treatment rendered the microfibril 

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There are two main strategies for disintegration of cellulose fibers down to their microfibrillar components (i) hydrolysis with strong acid and (ii) high shear mechanical treatment. 

It is of some interest that the mechanical treatment of poly(vinyI chloride) under conditions of high shear stress in the melt, in a Brabender Plastograph, was found to increase the degree of LCB, as estimated from deviations from the Mark-Houwink equation 204). This is presumably due to chain scission under the influence of the shear stress followed by attack of the radicals produced on other polymer chains, and subsequent recombination reactions. 

The next step is mechanical high shear treatment to break up the fat globule membrane. The fat then coalesces and the bulk aqueous phase (butter milk) are removed together with the fat globule membrane material to concentrate the fat. 

Calcium carbonate can be mixed with 0.5 to 1% by weight of stearic acid and subjected to high shear mixing at high temperatures. The stearic acid is converted to calcium stearate in the process. The treatment improves the processability, reduces moisture absorption, and improves the mechanical and electrical properties of the filled polymer. 

Mechanical treatment by oscillatory or vibrational compaction, high-pressure densification, or shear mixing. 

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