Polymers cellulosics

The most important of the esters is cellulose acetate. This material has been extensively used in the manufacture of films, moulding and extrusion compounds, fibres and lacquers. As with all the other cellulose polymers it has, however, become of small importance to the plastics industry compared with the polyolefins, PVC and polystyrene. In spite of their higher cost cellulose acetate-butyrate and cellulose propionate appear to have retained their smaller market because of their excellent appearance and toughness. 

A. Hebeish and J. T. Guthrie, The Chemistry and Technology of Cellulosic Polymers, Springer-Verlag, Berlin (1981). 

Dawsey TR (1994) In Gilbert RD (ed) Cellulosic Polymers, Blends and Composites. 

Poly(esters) and rubbers Poly(alkenes) and rubbers Cellulosic polymers, ethylene-vinyl acetate copolymers, poly(alkenes), PVC, rubbers, and poly(styrene) Cellulosic polymers, poly(esters), poly(alkenes), polyurethanes, PVC, rubbers, and poly(styrene)... 

The drill-in fluids are typically composed of either starch or cellulose polymers, xanthan polymer, and sized calcium carbonate or salt particulates. Insufficient degradation of the filter-cakes resulting from even these clean drill-in fluids can significantly impede the flow capacity at the wellbore wall. Partially dehydrated, gelled drilling fluid and filter-cake must be displaced from the wellbore annulus to achieve a successful primary cement job. 

S. Palumbo, D. Giacca, M. Ferrari, and P. Pirovano. The development of potassium cellulosic polymers and their contribution to the inhibition of hydratable clays. In Proceedings Volume, pages I73-I82. SPE Oilfield Chem Int Symp (Houston, TX, 2/8-2/10), 1989. 

The predominant RO membranes used in water applications include cellulose polymers, thin film oomposites (TFCs) consisting of aromatic polyamides, and crosslinked polyetherurea. Cellulosic membranes are formed by immersion casting of 30 to 40 percent polymer lacquers on a web immersed in water. These lacquers include cellulose acetate, triacetate, and acetate-butyrate. TFCs are formed by interfacial polymerization that involves coating a microporous membrane substrate with an aqueous prepolymer solution and immersing in a water-immiscible solvent containing a reactant [Petersen, J. Memhr. Sol., 83, 81 (1993)]. The Dow FilmTec FT-30 membrane developed by Cadotte uses 1-3 diaminobenzene prepolymer crosslinked with 1-3 and 1-4 benzenedicarboxylic acid chlorides. These membranes have NaCl retention and water permeability claims. 

Thomas, D.C. "Thermal Stability of Starch and Carboxymethyl Cellulose Polymers Used in Drilling Fluids," SPE Paper 8463, 1979 SPE Annual Technical Conference and Exhibition Las Vegas, September 23-26. 

Torr, R.S. "Particle Settling in Viscous Non Newtonian Hydroxyethyl Cellulose Polymer Solutions," AlChE Journal (Vol. 29, No. 3) May, 1983, pages 506 508. 

Water is a natural plasticizer for many polar polymers such as the nylons (23K). polyester resins (239), and cellulosic polymers (240). It strongly shifts in epoxies (241.242). Thus the creep and stress-relaxation behavior of such polymers can be strongly dependent on the relative humidity or the atmosphere. 

The general experimental methods of analysis and materials used in this study have been previously described(l,2) with the exception of the ionic hydroxyethyl cellulose polymers. 

The difference between hydrophobicities of the hydroxyethyl (HE) grouping and the hydroxypropyl (HP) unit is evident in the relative aqueous solution surface tensions(7,8) of the two cellulosic polymers in these comparative references the M.S. of the products is not equal. The dramatic influence of the more hydrophobic HP groupings on surface pressures is illustrated in Figure 2. 

Much of our technology has been developed by observing and imitating the natural world. Synthetic polymers, such as those you just encountered, were developed by imitating natural polymers. For example, the natural polymer cellulose provides most of the structure of plants. Wood, paper, cotton, and flax, are all composed of cellulose fibres. Figure 2.15 shows part of a cellulose polymer. 

Acetylation may be controlling the moisture sensitivity due to the lignin and hemlcellulose polymers in the cell wall but not reducing the sorption of moisture in the cellulose polymer because... 

Some clues may be available from studies of the decomposition of lignin. Lignin constitutes the second most abundant carbon polymer on earth after cellulose (46). The understanding of biodegradative pathways of lignin and lignin-cellulosic polymers may elucidate the problems of reduced plant productivity associated with surface residues in conservation production systems. 

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