Level-Off Degree of Polymerization

Battista, O. A.; Coppick, Sydney; Howsmon, J. A.; Morehead, F. F.; Sisson, Wayne A.

doi:10.1021/ie50554a046

Cited by 216 publications

(89 citation statements)

References 5 publications

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“…The length distribution of the cellulose nanocrystals (CNCs), which originate from the crystalline regions of cellulose, can be determined by hydrolysis with a strong acid followed by atomic force microscopy (AFM). The acid hydrolysis breaks the microfibril structure at the amorphous regions (Battista et al 1956). Drying does not change the length of the crystalline regions, but it does make the amorphous regions more susceptible to the acid hydrolysis (Steege and Philipp 1974).…”

Section: Proposed Mechanisms Of Cellulose Microfibril Coalescencementioning

confidence: 99%

Proposed Nano-Scale Coalescence of Cellulose in Chemical Pulp Fibers During Technical Treatments

Pönni¹,

Vuorinen²

2012

BioResources

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This review summarizes the proposed mechanisms for irreversible coalescence of cellulose microfibrils within fibers during various common industrial treatments for chemical pulp fibers as well as the methods to evaluate it. It is a phenomenon vital for cellulose accessibility but still under considerable debate. The proposed coalescence mechanisms include irreversible hydrogen bonding. Coalescence is induced by high temperature and by the absence of obstructing molecules, such as water, hemicelluloses, and lignin. The typical industrial processes, in the course of which nano-scale coalescence and possible aggregation of cellulose microfibrillar elements occurs, are drying and chemical pulping. Coalescence reduces cellulose accessibility and therefore, in several instances, the quality of cellulose as a raw material for novel products. The degree of coalescence also affects the processing and the quality of the products. For traditional paper-based products, the loss of strength properties is a major disadvantage. Some properties lost during coalescence can be restored to a certain extent by, e.g., beating. Several factors, such as charge, have an influence on the intensity of the coalescence. The evaluation of the phenomenon is commonly conducted by water retention value measurements. Other techniques, such as deuteration combined with FTIR spectroscopy, are being applied for better understanding of the changes in cellulose accessibility.

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Section: Proposed Mechanisms Of Cellulose Microfibril Coalescencementioning

confidence: 99%

Proposed Nano-Scale Coalescence of Cellulose in Chemical Pulp Fibers During Technical Treatments

Pönni¹,

Vuorinen²

2012

BioResources

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“…Cellulose liquefaction in an acidic ethylene glycol was analogous to hydrolysis for the breakage of the glycosidic bonds of cellulose chains (Jasiukaitytė et al 2009); the DP is reduced to a floor-level value, which is denoted as the leveling-off degree of polymerization (LODP). The LODP refers to the weight-average degree of polymerization of the macromolecules comprising of the discrete, colloidal, and unbonded microcrystals of the polymers (Battista et al 1956). The data in Table 1 shows that higher temperatures and catalyst dosages impacted the cellulose yield and DP.…”

Section: The Influence Of Reaction Conditions On the Liquefaction Yiementioning

confidence: 99%

Preparation of Microcrystalline Cellulose by Liquefaction of Eucalyptus Sawdust in Ethylene Glycol Catalyzed by Acidic Ionic Liquid

Chen

Liu

et al. 2017

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Microcrystalline cellulose (MCC) was prepared from the residue of the incomplete liquefaction of eucalyptus sawdust; atmospheric liquefaction was carried out using ethylene glycol as the solvent and 1-(4-sulfobutyl)-3-methylimidazolium hydrosulfate as the catalyst. The highest cellulose content in the residue reached 93.9%. The MCC prepared from liquefaction was characterized by various techniques, which included infrared spectroscopy, X-ray diffraction, thermo-gravimetric analysis, and scanning electron microscopy. The results were compared to those of a commercial MCC (cotton linters). The analyses indicated that hemicelluloses and lignin were removed extensively from the MCC produced from the sawdust. The MCC was a cellulose I polymorph with 79.0% crystallinity. The particles were shaped as elongated rods and had good thermal stability. The particle sizes of the produced MCC ranged from 1 µm to 100 µm with a mean of 38.6 µm.

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“…CNs are usually prepared by strong acid hydrolysis of cellulose. According to Ramires & Dufresne (2011), the first stable suspension of colloidal-sized cellulose crystals was produced using sulfuric acid hydrolysis by Rånby (1951) and closely followed by Battista et al (1956 potatoes are processed into value-added products to meet the demand of fast-food industries. Potatoes are usually peeled before processing, and as a result, large quantities of peels are produced as waste, which raises severe disposal issues.…”

Section: List Of Tablesmentioning

confidence: 99%

“…16 the raw material, with a typical value of 250 being for hydrolysed cotton (Battista, 1950), 300 for ramie fibers (Nishiyama et al, 2003), and 140-200 for bleached wood pulp (Battista, Coppick, Howsmon, Morehead & Sisson, 1956). However, a wide distribution of DPs is typically observed.…”

Section: 221preparation Of Cellulose Nanocrystalmentioning

confidence: 99%

Biocomposites reinforced with cellulose nanocrystals derived from potato peel waste

Chen

Lawton

Thompson

et al. 2012

Carbohydrate Polymers

226

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Cellulose is the most abundant biopolymer on earth, derived from a variety of living species. An attractive source to obtain cellulose is from agriculture wastes, for instance, potato peel. Potato is one of the most important crops for human consumption, but in recent years its consumption in raw form has decreased, especially in developed countries. Many potatoes are processed into value-added products to meet the demand of fast food industries. So far the main use of the potato peel is sold for animal feed at very low prices. In addition, there are significant quantities of rotten potatoes generated during the years of heavy rain fall, which represent a substantial financial loss to the farmers unless an alternative industrial use can be found for the biomass. Therefore, extracting cellulose from potato peel and processing them into a higher valuable product is not only an environment-friendly solution to the disposal issues but also creates a non-food based economy for potatoes.Cellulose nanocrystals (CN) are a promising material and have been widely studied over the past two decades. This material is interesting as nanofiller due to its nanoscale dimensions, high specific area, and highly rigid crystalline structure. In comparison to mineral or metal nanofillers that are industrially available, cellulose nanocrystals are prepared from renewable feedstocks, feature low density, are relatively low cost, and remain biodegradable. iv This study investigated the effectiveness of cellulose nanocrystal derived from potato peel waste to improve the mechanical and barrier properties of a polymer. The nanocrystals were chemically derived from the cellulosic material in potato peel waste by alkali treatment and subsequently acid hydrolysis with sulfuric acid. Infrared spectroscopy indicated sufficient removal of lignin and hemicellulose from the raw potato peel biomass whereas X-ray diffraction confirmed that the prepared nanocrystals maintained their original crystalline lattice structure as the extracted cellulose, with a crystallinity of 85%. TEM images showed that the average fiber length of the nanocrystals was 410 nm with a diameter of 10 nm (aspect ratio of 41). Cellulose nanocrystal-filled polyvinyl alcohol (PVA) and thermoplastic starch (TPS) were prepared by solution casting method to maintain uniform dispersion of the 1-2% (w/w) fibers. An increase of 19% and 38% (starch composite) and 32% and 54% (PVA composite) in Young's modulus was observed for the 1% and 2% CN-reinforced composites, respectively. Water vapor transmission rate measurements showed a reduction of water permeability for the PVA nanocomposite, whereas no effect was observed for starch nanocomposite.v

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Level-Off Degree of Polymerization

Cited by 216 publications

References 5 publications

Proposed Nano-Scale Coalescence of Cellulose in Chemical Pulp Fibers During Technical Treatments

Proposed Nano-Scale Coalescence of Cellulose in Chemical Pulp Fibers During Technical Treatments

Preparation of Microcrystalline Cellulose by Liquefaction of Eucalyptus Sawdust in Ethylene Glycol Catalyzed by Acidic Ionic Liquid

Biocomposites reinforced with cellulose nanocrystals derived from potato peel waste

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