Effect of antisolvents on the structure of regenerated cellulose: development of an efficient regeneration process

Holzforschung ◽  
2020 ◽  
Vol 74 (9) ◽  
pp. 881-890 ◽  
Author(s):  
Cuihua Dong ◽  
Yahui Meng ◽  
Binshou Wang ◽  
Wenyuan Zhu ◽  
Zhiqiang Pang
Keyword(s):  
Crystallinity Index ◽  
Downstream Processing ◽  
High Specific Surface Area ◽  
Degree Of Polymerization ◽  
Regenerated Cellulose ◽  
Low Degree ◽  
Effective Dispersion ◽  
Bond Network ◽  
Cellulose Regeneration ◽  
Kinetics Of

AbstractIn this study, the effect of antisolvents on the structure of regenerated microcrystalline cellulose (MCC) obtained from the extraction of 1-butyl-3-methylimidazolium chloride (BmimCl) was investigated; further, the usage of the aqueous N,N-dimethylmethanamide (DMF) solution was proposed as an effective antisolvent for cellulose regeneration. The results denoted that regeneration after dissolution resulted in a looser cellulose texture with a high specific surface area, low degree of polymerization (DP), low crystallinity index (CrI), and decreased thermostability, which are favorable for its downstream processing. Among the studied antisolvents, the DMF solution was superior in cellulose regeneration from BmimCl, as demonstrated by the kinetics of enzymatic hydrolysis. The improved ability of the DMF solution with respect to cellulose regeneration can be attributed to the effective dispersion of H-bonds and the inductive hydrophobic orientation of cellulose chains; correspondingly, a looser H-bond network was observed in the regenerated cellulose. The DMF solution as an antisolvent offers an effective cellulose regeneration method and an optimal structure for subsequent processing and applications.

scholarly journals Preparation of regenerated cellulose from rice straw lignocellulosic waste and its use for reinforced paper products

TAPPI Journal ◽  
2021 ◽  
Vol 20 (7) ◽  
pp. 439-451
Author(s):  
IZHAR ALAM ◽  
JITENDRA KUMAR ◽  
CHHAYA SHARMA
Keyword(s):  
Rice Straw ◽  
Fiber Length ◽  
Water Solution ◽  
Crystallinity Index ◽  
Degree Of Polymerization ◽  
Element Content ◽  
Hydroxyl Group ◽  
Regenerated Cellulose ◽  
Lignocellulosic Waste ◽  
Thawing Process

Rice straw waste is a lignocellulosic waste produced by farmers in large quantities. In this study, regenerated cellulose (RC) from rice straw was prepared by dissolving rice straw holocellulose (HC) in NaOH/Urea/Thiourea/Water solution by the freeze-thawing process. The crystallinity index of RC was calculated at 31%, which is out of the crystallinity range of 39%–69% that has been previously suggested. The study indicated that the RC is amorphous with a low degree of polymerization (638) and higher hydroxyl group content as compared to HC. The fiber length of RC was found to be 26.7% shorter; however, the width of RC was 21.2% higher as compared to HC. Reduced kinked fiber content was observed in the fraction of RC (18.3%) as compared with HC (39.1%), and a higher curl index of fiber was observed more so in HC (10.5%) than RC (5.6%). Because of the regeneration process, the fiber length was reduced and a fines element content of about 96% was observed in RC compared to the initial fines content of HC (56.9%). Irrespective of the high fines element content of RC, the composite paper of rice straw bleached pulp and RC fibers was developed with an increase in the tensile index from 41.4 N.m/g to 71.2 N.m/g and an increase in the burst index from 4.7 kPa.m2/g to 5.3 kPa.m2/g with the addition of 5% and 15% RC, respectively. However, enhanced tear index of paper was observed up to 5% and then it declined upon further addition of RC. The study revealed that regenerated cellulose can be used as a strength additive to overcome the shortcomings of low mechanical properties in paper products.

Halides of Macrocyclic Silver(II) Complexes: Crystal Structures with Hydrogen Bond Network and Reaction Kinetics of the Decomposition

2021 ◽  
pp. 120431
Author(s):  
Akinori Honda ◽  
Shunta Kakihara ◽  
Shuhei Ichimura ◽  
Kazuaki Tomono ◽  
Mina Matsushita ◽  
...  
Keyword(s):  
Hydrogen Bond ◽  
Reaction Kinetics ◽  
Crystal Structures ◽  
Hydrogen Bond Network ◽  
Bond Network ◽  
Kinetics Of

scholarly journals Oriented arrangement of simple monomers enabled by confinement: towards living supramolecular polymerization

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yingtong Zong ◽  
Si-Min Xu ◽  
Wenying Shi ◽  
Chao Lu
Keyword(s):  
Activation Barrier ◽  
Degree Of Polymerization ◽  
Supramolecular Polymer ◽  
Energy Principle ◽  
Spontaneous Nucleation ◽  
Pyrene Derivatives ◽  
Multifunctional Molecules ◽  
Double Hydroxide ◽  
Supramolecular Polymerization ◽  
Kinetics Of

AbstractThe living supramolecular polymerization technique provides an exciting research avenue. However, in comparison with the thermodynamic spontaneous nucleation, using simple monomers to realize living supramolecular polymerization is hardly possible from an energy principle. This is because the activation barrier of kinetically trapped simple monomer (nucleation step) is insufficiently high to control the kinetics of subsequent elongation. Here, with the benefit of the confinement from the layered double hydroxide (LDH) nanomaterial, various simple monomers, (such as benzene, naphthalene and pyrene derivatives) successfully form living supramolecular polymer (LSP) with length control and narrow dispersity. The degree of polymerization can reach ~6000. Kinetics studies reveal LDH overcomes a huge energy barrier to inhibit undesired spontaneous nucleation of monomers and disassembly of metastable states. The universality of this strategy will usher exploration into other multifunctional molecules and promote the development of functional LSP.

Comparative Study on Structural Performance of Several New Regenerated Cellulose Fibers

2012 ◽  
Vol 573-574 ◽  
pp. 174-180
Author(s):  
Rong Zhou ◽  
Chun Guang Li ◽  
Ming Xia Yang
Keyword(s):  
Cellulose Fiber ◽  
Degree Of Polymerization ◽  
Structural Performance ◽  
Regenerated Cellulose ◽  
Pulp Fiber ◽  
Bast Fiber ◽  
Bamboo Pulp ◽  
Lyocell Fiber ◽  
Regenerated Cellulose Fiber ◽  
Sectional Shape

Regenerated cellulose fiber is the most widely-used and most variety of cellulose fiber. Five categories and ten kinds of fibers such as lyocell fiber, viscose fiber, modal fiber, bamboo pulp fiber, and sheng-bast fiber were chosen as the research object. The sectional shape, crystallinity and degree of polymerization of fibers were tested and analysis, to explore the nature of the reasons for the formation of fiber performance difference, and to verify through experiments.

The kinetics of the polymerization of styrene initiated by n -butyl lithium in hydrocarbon media

1962 ◽  
Vol 268 (1333) ◽  
pp. 260-275 ◽  
Keyword(s):  
Degree Of Polymerization ◽  
Complete Conversion ◽  
Initiator Concentration ◽  
Butyl Lithium ◽  
Initiation And Propagation ◽  
Quantitative Results ◽  
Kinetics Of ◽  
Hydrocarbon Media

The kinetics of the polymerization of styrene initiated by n-butyl lithium in hydrocarbon media has been studied under conditions where both initiation and propagation of growing chains takes place simultaneously and in the absence of a termination reaction. Under the conditions employed, the initiator is incompletely consumed at complete conversion of monomer to polymer and consequently the degree of polymerization of the polystyrene is greater than the ratio of monomer to initiator concentration. The quantitative results support the mechanism previously proposed by Worsfold & By water for this polymerization.

scholarly journals Affinity Membranes and Monoliths for Protein Purification

Membranes ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 1 ◽  
Author(s):  
Eleonora Lalli ◽  
Jouciane S. Silva ◽  
Cristiana Boi ◽  
Giulio C. Sarti
Keyword(s):  
Binding Capacity ◽  
Stationary Phases ◽  
Packed Column ◽  
Downstream Processing ◽  
Regenerated Cellulose ◽  
Affinity Capture ◽  
Scale Characterization ◽  
Set Up ◽  
Cellulose Membranes ◽  
Chromatographic Media

Affinity capture represents an important step in downstream processing of proteins and it is conventionally performed through a chromatographic process. The performance of this step highly depends on the type of matrix employed. In particular, resin beads and convective materials, such as membranes and monoliths, are the commonly available supports. The present work deals with non-competitive binding of bovine serum albumin (BSA) on different chromatographic media functionalized with Cibacron Blue F3GA (CB). The aim is to set up the development of the purification process starting from the lab-scale characterization of a commercially available CB resin, regenerated cellulose membranes and polymeric monoliths, functionalized with CB to identify the best option. The performance of the three different chromatographic media is evaluated in terms of BSA binding capacity and productivity. The experimental investigation shows promising results for regenerated cellulose membranes and monoliths, whose performance are comparable with those of the packed column tested. It was demonstrated that the capacity of convective stationary phases does not depend on flow rate, in the range investigated, and that the productivity that can be achieved with membranes is 10 to 20 times higher depending on the initial BSA concentration value, and with monoliths it is approximately twice that of beads, at the same superficial velocity.

Clinical Evaluation of Class I Restorations Made with Composite with Low Degree of Polymerization Shrinkage

2016 ◽  
Vol 16 (9) ◽  
pp. 1-7 ◽  
Author(s):  
Carlos Gasparello ◽  
Carlos Nassar ◽  
Priscilla Busato ◽  
Márcio Mendonça ◽  
Lyvia Bertacchini ◽  
...  
Keyword(s):  
Clinical Evaluation ◽  
Degree Of Polymerization ◽  
Class I ◽  
Polymerization Shrinkage ◽  
Low Degree

Effects of Treatments on Cellulosic Biomass Structure in Ethanol Manufacturing: A Literature Review

2011 ◽  
Author(s):  
Qi Zhang ◽  
Pengfei Zhang ◽  
Z. J. Pei ◽  
Linda Pei
Keyword(s):  
Particle Size ◽  
Enzymatic Hydrolysis ◽  
Literature Review ◽  
Crystallinity Index ◽  
Degree Of Polymerization ◽  
Cellulosic Biomass ◽  
Experimental Investigations ◽  
Structure Parameters ◽  
Transportation Fuels ◽  
Biomass Structure

Ethanol made from cellulosic biomass is an alternative to petroleum-based liquid transportation fuels. Enzymatic hydrolysis uses enzymes to convert cellulosic biomass into sugars that are fermented into ethanol. In order to increase sugar yield, various treatments (such as biomass size reduction and pretreatment) are applied to cellulosic biomass before enzymatic hydrolysis. These treatments will alter structure parameters of cellulosic biomass, such as crystallinity index, degree of polymerization, particle size, pore volume, and specific surface area. There are currently no review papers on these structure parameters of cellulosic biomass in ethanol manufacturing. This paper reviews experimental investigations in the literature about effects of various treatments on the structure parameters of cellulosic biomass.

Sign in / Sign up

Export Citation Format

Share Document