Hemp, cellulose

The grafting of ethyl acrylate onto sunn hemp cellulose (SHC) should follow the proposed mechanism given in Figure 2.2. The optimal time of polymerization onto SHF is found to be 40 minutes [54]. 

Figure 2.2 Proposed mechanism of grafting of ethyl acrylate onto sunn hemp cellulose (SHC) [54].

Ouajai S, Shanks RA (2009) Biocomposites of cellulose acetate but3uate with modified hemp cellulose fibres. Macromol Mater Eng 294(3) 213-221... 

Hemp Cellulose acetate and Polyhydroxybutyrate Lamination Replacing wood and engineered wood products in the construction industry [22]... 

Chen et al. (2008) studied the mechanical properties of composite films from the suspension of hemp cellulose nanocrystals (HCNs) and thermoplastic starch. The films exhibited significant increase in the tensile strength and Young s modulus, with increasing HCN content from 0 to 30 wt% of HCNs. In addition to the improvement in mechanical properties, the incorporation of HCNs into the PS matrix also led to a decrease in the water sensitivity of the final composite materials. Therefore, the CNs played an important role in improving the mechanical properties and water resistance of the starch-based material. 

Ouajai, S. and Shanks, R.A. (2005) Composition, structure and thermal degradation of hemp cellulose after chemical treatments. Polym. Degrad. 

Sunn hemp cellulose graft copolymers polyhydroxybutyrate composites morphological and mechanical studies. Adv. Mat. Lett., 2, 17—25. 

Fibers (see Fibers, survey) used in textile production can have a wide variety of origins plants, ie, ceUulosic fibers (see Fibers, cellulose esters) animals, ie, protein fibers (see Wool) and, in the twentieth century, synthetic polymers. Depending on the part of the plant, the ceUulosic fibers can be classified as seed fibers, eg, cotton (qv), kapok bast fibers, eg, linen from flax, hemp, jute and leaf fibers, eg, agave. Protein fibers include wool and hair fibers from a large variety of mammals, eg, sheep, goats, camels, rabbits, etc, and the cocoon material of insect larvae (sUk). Real sUk is derived from the cocoon of the silkworm, Bombjx mori and for a long time was only produced in China, from which it was traded widely as a highly valuable material. 

Vegetable (based on cellulose) cotton (qv), linen, hemp, jute, ramie Animal (based on proteias) wool (qv), mohair, vicuna, other animal hairs, silk Mineral asbestos (qv)... 

Nitromatweed (Matweed Nitrate, Nitrosparte in Fr). Prepd by nitration of dried matweed with mixed nitric-sulfuric acids in a manner similar to the prepn of NC. Trench, Faure and MacKie (Ref 2), in 1876, patented expls containing as a base nitrosparte (or other nitrated cellulosic material such as cotton, hay, agave, hemp, flax, straw, aloe, yucca, etc) together with resin, ozokerite, collodion, glycerin, charcoal and soot. Hengst (Ref 3), in 1898, patented a smokeless powd containing nitrosparte prepd by nitration of fibers covering the coconut shell Refs 1) Merriam Webster s Diet, 2nd Ed (1963), ... 

Paper and board are composed of cellulose obtained by the mechanical or semi-chemical treatment of vegetable fibers (pulp) derived from various sources like wood, hemp, cotton, etc. In some cases waste and regenerated paper is used. 

A basic scientific investigation of fire retardancy, however, remained to be initiated by Gay-Lussac in France at the request of King Louis XVIII in 1821 who was again interested in reducing the flammability of theater curtains. This researcher noted that the ammonium salts of sulfuric, hydrochloric and phosphoric acids were very effective fire retardants on hemp and linen and that the effect could be improved considerably by using mixtures of ammonium chloride, ammonium phosphate and borax. This work has withstood the test of time and remains valid to this day. Thus the basic elements of modern fire retardant chemistry had been defined early in recorded history and remained the state of the art until early in the twentieth century. The most effective treatments for cellulosic materials being concentrated in Groups III, V and VII elements. 

In 1857, Schweizer discovered that ammoniacal solutions of copper hydroxide could dissolve cellulose. Cellulose is a versatile polymer which is found in plenty in nature in the form of cotton, hemp, jute, flax, etc. In 1891, first attempts were made to spin a solution of cellulose. The cellulose produced like this is known as Bemberg Rayon and is still being produced commercially in Germany, Italy, Japan and USA. 

For battery separators, regenerated cellulose is placed on the surface of nonwoven so that the nonwoven is available to promote the wicking of the electrolyte. The nonwovens should not allow the penetration of viscose into itself. Suitable nonwovens are made from polypropylene, poly(vinyl alcohol), and hardwood hemps. Regenerated cellulose films are commonly used in alkaline manganese cells, both primary and secondary, in NiCd industrial batteries, as well as in silver—zinc batteries. 

It has little, if any, adverse effect on the lung, and there are no reports of organic disease or toxic effect. The health effects attributed to wood, cotton, flax, jute, and hemp are not attributable to their cellulose content but rather to the presence of other substances. 

Nature has long used reactions such as these to produce interesting solids such as cotton (seed pod), hemp (grass), and silk (cocoons for worms while they develop into moths) as fibers that we can strand into rope or weave into cloth. Chemists discovered in the early twentieth century that cellulose could be hydrolyzed with acetic acid to form cellulose acetate and then repolymerized into Rayon, which has properties similar to cotton. They then searched for manmade monomers with which to tailor properties as replacements for rope and sdk. In the 1930s chemists at DuPont and at ICl found that polyamides and polyesters had properties that could replace each of these. [Linear polyolefins do not seem to form in nature as do condensation polymers. This is probably because the organometaUic catalysts are extremely sensitive to traces of H2O, CO, and other contaminants. This is an example where we can create materials in the laboratory that are not found in nature.]... 

Secondary-cellulose deposition occurs after cessation of expansion of the primary wall. Layers of the secondary wall, in contrast to the primary wall, display a very orderly, parallel arrangement of the microfibrils. In such plants as flax and hemp,1,2 bamboo,13 sisal,14-16 cotton hairs,2 and pine tracheids,13 three main layers can be detected in the secondary wall, each made up of cellulose microfibrils arranged in a helical fashion around the cell, In each of these secondary walls, the middle layer of cellulose is considerably thicker than the cellulose layers on each side of it, with a helical direction opposed to those of the latter. It is probable that each of these three layers is, in fact, complex, and made from a number of lamellae, each with its own helix of cellulose microfibrils.1 2... 

Hemp - pIBERS - VEGETABLE] (Vol 10) -cellulose source [CELLULOSE] (Vol 5)... 

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