Cellulose prior research

TABLE VII. A Summary of the Results of Prior Research on the Flash Pyrolysis of Cellulose... 

Researchers in previous studies generally used lst-order kinetics to describe cellulose pyrolysis, but rarely have they examined 2nd-order kinetics. Thus, discussion of our results for untreated samples will concentrate on lst-order rate constants so that our results can be directly compared with results from prior studies. A true reaction order of cellulose pyrolysis based on TGA data is essentially meaningless, however, since mass loss involves complex competing multiple reactions (2,4,8). In addition, reaction order was calculated on a dimensionless mass value rather than on the correct but uncalculable molar concentration term. 

As a result of prior field experience with the furan system, a qualifying test has been employed at Albany International Research Co. to measure the durability. Table III displays data of typical samples tested against synthetic seawater at 1000 psig maintained at a temperature of 50°C. Samples of cellulosic seawater membrane and polyamide membrane were found to fail in several hours of challenge by these conditions. 

These compositional considerations necessitate attention to raw materials evaluation early in process research and development to (1) establish an in-depth knowledge of the principal raw material, including its composition and history of materials handling prior to arrival at the factory, (2) investigate the effects of seasonal variations and storage under various conditions on composition and on hydrolytic performance, and (3) explore alternative pretreatment processes for upgrading the composition and hydrolytic performance of available raw materials. The resource that is for sale is not pure cellulose it is a complex mixture containing cellulose caveat emptor. 

It was not possible to evaluate insoluble pigments such as zinc oxide for their effectiveness as UV stabilizers in the cellulose acetate films because the centrifugation necessary to remove air bubbles prior to film casting caused such insoluble materials to be distributed unevenly in the casting solution. Therefore, a soluble experimental stabilizer, zinc acetate dihydrate (UV-4) was chosen for this study. Although previous research... 

While many researchers use bacterial cellulose in its native form to create polymers, and some treat the bacterial cellulose by homogenization or hydrolyzation prior to casting, there is very little in the literature about the dissolution of bacterial cellulose as part of a method to create composites. One method that has used the dissolution of bacterial cellulose is electrospinning. Chen et al. [148] used the ionic liquid 1-allyl-3-methylimidazolium chloride to dissolve freeze-dried bacterial cellulose pieces at 70°C while stirring. DMSO was added to the solution to adjust the viscosity at room... 

One s first experiments in an area are seldom clean, clear, or completely explicable. False starts are common, and misinterpretations rife. Points, or intersections, are reached where decisions must be made as to future research directions. Most cellulose notebooks seldom explain why decisions were taken, and if they do, only the selected forward path is developed in detail. The untaken paths remain undescribed. This makes it difficult to backtrack, particularly for other scientists taking up the work. Any feedback in the project s flow, connecting prior work with current work, is usually logged in the mind of the worker, not in the notebook. Long-term (period) analysis is usually lacking, and attempts to put milestones in place are uncommon. In fact, most cellulose notebooks are organizationally challenged. An electronic journal can help the user create a feedback log that explicitly shows connections, and makes use of the other log forms simple and useful. 

Of all the fibers that have (and are still) evaluated in rubber compounds over the last 30 years, only treated imregenerated cellulose fibers and chopped aramid fibers have really achieved a certain industrial importance. The current research efforts being made, essentially by university groups in the producing countries, on natural fibers such as jute, sisal, kenaf, etc., are not (yet) leading to documented industrial applications, at least to the author s knowledge. Actual reasons for this situation are imclear, except maybe that industrial applications for treated imregenerated cellulose fibers were inherited from the important preliminary works by former Monsanto s scientists, prior to the commercial development of Santoweb fibers. When... 

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