Lignin Behavior During the Autocatalyzed Methanol Pulping of Eucalyptus globulus Changes in Molecular Weight and Functionality

Holzforschung ◽  
2000 ◽  
Vol 54 (4) ◽  
pp. 373-380 ◽  
Author(s):  
Miguel A. Gilarranz ◽  
Francisco Rodríguez ◽  
Mercedes Oliet
Keyword(s):  
Molecular Weight ◽  
Eucalyptus Globulus ◽  
Functional Group ◽  
Alcohol Concentration ◽  
Empirical Models ◽  
Cooking Time ◽  
Surface Response Design ◽  
Central Composite ◽  
Low Alcohol ◽  
Cooking Conditions

Summary The molecular weight distribution and functional group contents (phenolic and carbonyl) of lignin samples from the autocatalyzed pulping of Eucalyptus globulus wood were determined. A total of 17 pulping runs were carried out at different conditions according to a surface response design experimental matrix (central composite). The influence of pulping temperature (170–200°C), pulping time (40–120 min) and methanol concentration (30–70%, w/w) on the characteristics of the isolated lignins was studied. Empirical models were developed and used to predict the lignin properties as a function of the cooking conditions. Under high temperature, long cooking time and low alcohol concentration, a rise in functional groups content and a drop in molecular weight of lignin

Organic material dissolved during oxygen-alkali pulping of hot water extracted birch sawdust

TAPPI Journal ◽  
2015 ◽  
Vol 14 (4) ◽  
pp. 237-244 ◽  
Author(s):  
JONI LEHTO ◽  
RAIMO ALÉN
Keyword(s):  
Acetic Acid ◽  
Betula Pendula ◽  
Cooking Time ◽  
Hot Water ◽  
Partial Hydrolysis ◽  
Chemical Pulping ◽  
Black Liquors ◽  
Aliphatic Carboxylic Acids ◽  
Hydrolysis Of ◽  
Cooking Conditions

Untreated and hot water-treated birch (Betula pendula) sawdust were cooked by the oxygen-alkali method under the same cooking conditions (temperature = 170°C, liquor-to-wood ratio = 5 L/kg, and 19% sodium hydroxide charge on the ovendry sawdust). The pretreatment of feedstock clearly facilitated delignification. After a cooking time of 90 min, the kappa numbers were 47.6 for the untreated birch and 10.3 for the hot water-treated birch. Additionally, the amounts of hydroxy acids in black liquors based on the pretreated sawdust were higher (19.5-22.5g/L) than those in the untreated sawdust black liquors (14.8-15.5 g/L). In contrast, in the former case, the amounts of acetic acid were lower in the pretreated sawdust (13.3-14.8 g/L vs. 16.9-19.1 g/L) because the partial hydrolysis of the acetyl groups in xylan already took place during the hot water extraction of feedstock. The sulfur-free fractions in the pretreatment hydrolysates (mainly carbohydrates and acetic acid) and in black liquors (mainly lignin and aliphatic carboxylic acids) were considered as attractive novel byproducts of chemical pulping.

scholarly journals Effects of Molecular Weight of Functionalized Liquid Butadiene Rubber as a Processing Aid on the Properties of SSBR/Silica Compounds

Polymers ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 850
Author(s):  
Donghyuk Kim ◽  
Byungkyu Ahn ◽  
Kihyun Kim ◽  
JongYeop Lee ◽  
Il Jin Kim ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Anionic Polymerization ◽  
High Performance ◽  
Crosslink Density ◽  
Functional Group ◽  
Vital Role ◽  
Butadiene Rubber ◽  
Molecular Weights ◽  
Mooney Viscosity ◽  
Silica Dispersion

Liquid butadiene rubber (LqBR) which used as a processing aid play a vital role in the manufacturing of high-performance tire tread compounds. However, the studies on the effect of molecular weight, microstructure, and functionalization of LqBR on the properties of compounds are still insufficient. In this study, non-functionalized and center-functionalized liquid butadiene rubbers (N-LqBR and C-LqBR modified with ethoxysilyl group, respectively) were synthesized with low vinyl content and different molecular weights using anionic polymerization. In addition, LqBR was added to the silica-filled SSBR compounds as an alternative to treated distillate aromatic extract (TDAE) oil, and the effect of molecular weight and functionalization on the properties of the silica-filled SSBR compound was examined. C-LqBR showed a low Payne effect and Mooney viscosity because of improved silica dispersion due to the ethoxysilyl functional group. Furthermore, C-LqBR showed an increased crosslink density, improved mechanical properties, and reduced organic matter extraction compared to the N-LqBR compound. LqBR reduced the glass transition temperature (Tg) of the compound significantly, thereby improving snow traction and abrasion resistance compared to TDAE oil. Furthermore, the energy loss characteristics revealed that the hysteresis loss attributable to the free chain ends of LqBR was dominant.

Diaminomalenonitrile-decorated cholesterol-based supramolecular gelator: aggregation, multiple analyte (hydrazine, Hg2+ and Cu2+) detection and dye adsorption

2018 ◽  
Vol 42 (16) ◽  
pp. 13718-13725 ◽  
Author(s):  
Atanu Panja ◽  
Kumaresh Ghosh
Keyword(s):  
Molecular Weight ◽  
Functional Group ◽  
Dye Adsorption ◽  
Low Molecular Weight ◽  
Practical Applications ◽  
Supramolecular Gels ◽  
Low Molecular Weight Gelator

A low molecular weight gelator (LMWG) containing a diaminomalenonitrile functional group 1 forms supramolecular gels from DMF–H2O and 1,2-dichlorobenzene. The DMF/H2O gel is multi-analyte responsive (Hg2+, Cu2+ and hydrazine) with practical applications in dye adsorption from water.

Impact of cannabis and low alcohol concentration on divided attention tasks during driving

2020 ◽  
pp. 1-7
Author(s):  
Ryan E. Miller ◽  
Timothy L. Brown ◽  
Stella Lee ◽  
Ishaan Tibrewal ◽  
Gary G. Gaffney ◽  
...  
Keyword(s):  
Divided Attention ◽  
Alcohol Concentration ◽  
Attention Tasks ◽  
Low Alcohol

Functional segmented polymer networks based on polytetrahydrofuran and poly(vinylbenzyl chloride)

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Laura Jonckheere ◽  
Eric J. Goethals ◽  
Filip E. Du Prez
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Free Radical ◽  
Functional Group ◽  
Composition Range ◽  
Soluble Fraction ◽  
Thermal Analyses ◽  
Polymer Networks ◽  
Wide Composition Range ◽  
Elemental Analyses

Abstract Functional segmented polymer networks (FSPNs) were synthesised via free radical initiated copolymerisation of polytetrahydrofuran (PTHF) bis-macromonomers with vinylbenzyl chloride (VBCl). The purpose of this work was to create FSPNs, providing supports with a functional group that can be substituted and may serve to immobilise other reagents such as catalysts. After the preparation and detailed characterisation of several PTHF bis-macromonomers, FSPNs were prepared with varying molecular weight of the PTHF chain and varying PTHF/ PVBCl ratio. Measurements of the soluble fraction and elemental analyses demonstrated that FSPNs with a wide composition range could be prepared. From dynamic-mechanical and thermal analyses, it could be concluded that most FSPNs showed some degree of compatibility and complete absence of crystallinity. The mechanical properties of the FSPNs are directly related to their composition. The degree of substitution of all networks is close to quantitative.

Synthesis of Polystyrene-B-Poly(Ethylene Oxide)monomethyl Ethermethacrylate Block Copolymers and its Self-Assembly in Aqueous Solution

2011 ◽  
Vol 284-286 ◽  
pp. 769-772
Author(s):  
Qian Qian You ◽  
Pu Yu Zhang
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Block Copolymers ◽  
Self Assembly ◽  
Chain Transfer ◽  
Functional Group ◽  
Transmission Electron ◽  
Reversible Addition ◽  
Ft Ir ◽  
A Chain

The block copolymer of PSt-b-POEOMA with the end of -COOH functional group has been synthesized by reversible addition fragmentation chain-transfer (RAFT) using S,S′-Bis(α,α′-dimethyl-α′′-acetic acid)-trithiocarbonate (BDATC) as a chain transfer agent. The architectures of the copolymers were confirmed by FT-IR and 1HNMR spectra. GPC analysis was used to estimate the molecular weight and the molecular weight distribution of the copolymers. Meanwhile, The nanostructures of the block copolymers PSt-b-POEOMA micelles formed in aqueous solution were observed by transmission electron microscopy (TEM) and dynamic light scattering (DLS).

scholarly journals Quality of Cultured Wader Pari During Storage at Different Temperature

2017 ◽  
Vol 20 (2) ◽  
pp. 339 ◽  
Author(s):  
Mala Nurilmala ◽  
Agoes Mardiono Jacoeb ◽  
Rofi Ahmad Dzaky
Keyword(s):  
Molecular Weight ◽  
Functional Group ◽  
Gel Strength ◽  
Yellowfin Tuna ◽  
Fish Skin ◽  
Alternative Source ◽  
Food Industries ◽  
Sds Page ◽  
Fish Skin Gelatin

Gelatin is one of the products which become a necessity for various industries, i.e. food and non-food industries. The application of gelatin has been increasing year by year in Indonesia. However, there is no<br />gelatin industry in Indonesia so far. Thus, it is necessary to find an alternative source of gelatin, especially from fishery by products.Thus, the purpose of this research was to extract fish skin gelatin of yellowfin tuna with temperature treatments (55, 65 and 75oC). In addition, the properties of resulted gelatin were determined including yield, pH, gel strength, viscosity, functional groups, molecular weight profiles, and amino acid composition. The extraction at 75oC was chosen as the best result. The yield was 17%; pH 5.3; gel strength 1789.55 gf, viscosity 104.2 Cp, respectively. There was functional group amide A, I, II, dan III. SDS-PAGE showed β, α1 dan α2 bands for tuna skin gelatin. In addition, the main amino acids were glycine and proline.

scholarly journals Mathematical Modelling and Optimisation of Low-Temperature Drying on Quality Aspects of Rough Rice

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Shakeel Ahmed Soomro ◽  
Kunjie Chen ◽  
Sohail Ahmed Soomro
Keyword(s):  
Low Temperature ◽  
Central Composite Design ◽  
Cooking Time ◽  
Quadratic Model ◽  
Rough Rice ◽  
Quality Aspects ◽  
Tropical Conditions ◽  
Low Temperature Drying ◽  
Central Composite

Rice when harvested normally has a high moisture content of 20–25% which requires immediate drying, reducing its mass loss and preventing it to spoil. This situation is more crucial with the areas under humid tropical conditions, where moisture and temperature mainly play an important role in deteriorating the quality of rough rice. Keeping the importance of quality attributes of rough rice, the study was carried out to assess the effects of low-temperature drying and suggest an optimum condition. Response surface methodology (RSM) with a central composite design was employed to study the effects of variables, i.e., temperature (X1), time (X2), and air velocity (X3) on responses, i.e., head rice yield (HRY), hardness, lightness, and cooking time. The experimental data were fitted to the quadratic model, studying the relationship between independent and dependent variables. The results revealed that the HRY, hardness, lightness, and cooking time increased with increasing variables, whereas for HRY, it particularly increased and then decreased. It was observed that temperature had more influence on the quality of rough rice followed by time and velocity. Results for analysis of variance revealed that the quality aspects of rough rice were significantly (p<0.05) affected by temperature and time, whereas for velocity, it only significantly affected hardness. The optimal drying conditions predicted by RSM for variables were 25°C, 600 min, and 1 m·s−1, and the optimal predicted HRY, hardness, lightness, and cooking time were 73.93%, 38.28 N, 71.40, and 27.58 min respectively. Acceptable values of R2, Adj R2, and nonsignificance of lack of fit demonstrated that the model applied was adequate and can be used for optimization. The study concluded that the RSM with a central composite design was successfully used to study the dependence of quality aspects of rough rice at low temperature and can be utilized by the rice processing industries.

scholarly journals Structural control of magnetite nanoparticles for hyperthermia by modification with organic polymers: effect of molecular weight

RSC Advances ◽  
2020 ◽  
Vol 10 (44) ◽  
pp. 26374-26380 ◽  
Author(s):  
Toshiki Miyazaki ◽  
Takayuki Tange ◽  
Masakazu Kawashita ◽  
Balachandran Jeyadevan
Keyword(s):  
Molecular Weight ◽  
Magnetic Properties ◽  
Crystalline Structure ◽  
Magnetite Nanoparticles ◽  
Structural Control ◽  
Functional Group ◽  
Organic Polymers

Crystalline structure and magnetic properties of magnetite nanoparticles are highly governed by functional group and molecular weight of the added polymers.

scholarly journals Optimization of N, P, K for Soilless Production of Cannabis sativa in the Flowering Stage Using Response Surface Analysis

2021 ◽  
Author(s):  
Lewys Bevan ◽  
Max Jones ◽  
Youbin Zheng
Keyword(s):  
Cannabis Sativa ◽  
Scientific Data ◽  
Flowering Stage ◽  
Horticultural Crop ◽  
Yield And Quality ◽  
Legal Restrictions ◽  
Surface Response Design ◽  
The Relationship ◽  
Central Composite ◽  
Nutrient Solutions

Following legalization, cannabis has quickly become an important horticultural crop in Canada and increasingly so in other parts of the world. However, due to previous legal restrictions on cannabis research there are limited scientific data on the relationship between nitrogen (N), phosphorus (P), and potassium (K) supply (collectively: NPK) and the crop yield and quality. This study examined the response of a high delta-9-tetrahydrocannabinol (THC) Cannabis sativa cultivar grown in deep-water culture with different nutrient solution treatments varying in their concentrations (mg L-1) of N (70, 120, 180, 250, 290), P (20, 40, 60, 80, 100) and K (60, 120, 200, 280, 340) according to a central composite design. Results demonstrated that inflorescence yield responded quadratically to N and P, with the optimal concentrations predicted to be 194 and 59 mg L-1, respectively. Inflorescence yield did not respond to K in the tested range. These results can provide guidance to cultivators when formulating nutrient solutions for soilless cannabis production and demonstrates the utility of surface response design for efficient multi-nutrient optimization.

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