scholarly journals Valorization of Rice Straw via Hydrotropic Lignin Extraction and Its Characterization

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4123
Author(s):  
Chongxin Yin ◽  
Min Wang ◽  
Qingzhi Ma ◽  
Huiyang Bian ◽  
Hao Ren ◽  
...  
Keyword(s):  
Rice Straw ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
Aryl Ether ◽  
Ether Linkage ◽  
High Severity ◽  
Lignin Extraction ◽  
Toluene Sulfonic Acid ◽  
Carboxyl Group Content ◽  
Nanoscale Particle Size

Rice straw hydrotropic lignin was extracted from p-Toluene sulfonic acid (p-TsOH) fractionation with a different combined delignification factor (CDF). Hydrotropic lignin characterization was systematically investigated, and alkaline lignin was also studied for the contrast. Results showed that the hydrotropic rice straw lignin particle was in nanometer scopes. Compared with alkaline lignin, the hydrotropic lignin had greater molecular weight. NMR analysis showed that β-aryl ether linkage was well preserved at low severities, and the unsaturation in the side chain of hydrotropic lignin was high. H units and G units were preferentially degraded and subsequently condensed at high severity. High severity also resulted in the cleavage of part β-aryl ether linkage. 31P-NMR showed the decrease in aliphatic hydroxyl groups and the increasing carboxyl group content at high severity. The maximum weight loss temperature of the hydrotropic lignin was in the range of 330–350 °C, higher than the alkaline lignin, and the glass conversion temperature (Tg) of the hydrotropic lignin was in the range of 107–125 °C, lower than that of the alkaline lignin. The hydrotropic lignin has high β-aryl ether linkage content, high activity, nanoscale particle size, and low Tg, which is beneficial for its further valorization.

Tailored Mesoporous Silicas: From Confinement Effects to Catalysis

2009 ◽  
Vol 1217 ◽  
Author(s):  
A. C. Buchanan, III ◽  
Michelle K. Kidder
Keyword(s):  
Chemical Reactivity ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Silicas ◽  
Surface Immobilization ◽  
Product Selectivity ◽  
Aryl Ether ◽  
Ether Linkage ◽  
Synthetic Methodologies ◽  
The Impact

AbstractOrdered mesoporous silicas continue to find widespread use as supports for diverse applications such as catalysis, separations, and sensors. They provide a versatile platform for these studies because of their high surface area and the ability to control pore size, topology, and surface properties over wide ranges. Furthermore, there is a diverse array of synthetic methodologies for tailoring the pore surface with organic, organometallic, and inorganic functional groups. In this paper, we will discuss two examples of tailored mesoporous silicas and the resultant impact on chemical reactivity. First, we explore the impact of pore confinement on the thermochemical reactivity of phenethyl phenyl ether (PhCH2CH2OPh, PPE), which is a model of the dominant β-aryl ether linkage present in lignin derived from woody biomass. The influence of PPE surface immobilization, grafting density, silica pore diameter, and presence of a second surface-grafted inert “spacer” molecule on the product selectivity has been examined. We will show that the product selectivity can be substantially altered compared with the inherent gas-phase selectivity. Second, we have recently initiated an investigation of mesoporous silica supported, heterobimetallic oxide materials for photocatalytic conversion of carbon dioxide. Through surface organometallic chemistry, isolated M-O-M’ species can be generated on mesoporous silicas that, upon irradiation, form metal to metal charge transfer bands capable of converting CO2 into CO. Initial results from studies of Ti(IV)-O-Sn(II) on SBA-15 will be presented.

Post-functionalization of perfluorocyclobutyl aryl ether polymers with a novel perfluorosulfonated side chain precursor

2019 ◽  
Vol 26 (5) ◽  
Author(s):  
Liping Bi ◽  
Jiangjian Hong ◽  
Shining Li ◽  
Zhengfang Zhu ◽  
Yuanqin Zhu
Keyword(s):  
Side Chain ◽  
Aryl Ether ◽  
Post Functionalization

scholarly journals Poly(arylene ether)s with aromatic azo-coupled cobalt phthalocyanines in the side chain: synthesis, characterization and nonlinear optical and optical limiting properties

RSC Advances ◽  
2019 ◽  
Vol 9 (16) ◽  
pp. 9253-9259 ◽  
Author(s):  
Yuxuan Zhang ◽  
Saisai Gai ◽  
Zhonghui Wang ◽  
Shuang Wang ◽  
An Sui ◽  
...  
Keyword(s):  
Nonlinear Optical ◽  
Optical Limiting ◽  
Side Chain ◽  
Cobalt Phthalocyanine ◽  
Aryl Ether ◽  
Cobaltous Chloride ◽  
Arylene Ether ◽  
Cobalt Phthalocyanines ◽  
Chain Synthesis

A novel poly(arylene ether) with azo-coupled cobalt phthalocyanine in the side chain was prepared by 1,2-benzodinitrile, anhydrous cobaltous chloride and a novel azobenzene-containing poly(aryl ether).

Convenient preparation of a β-O-4-type lignin model trimer via KOH-catalyzed hydroxymethylation and a new protection method

Holzforschung ◽  
2013 ◽  
Vol 67 (2) ◽  
pp. 129-136 ◽  
Author(s):  
Maarit Lahtinen ◽  
Anssi Haikarainen ◽  
Jussi Sipilä
Keyword(s):  
Model Compound ◽  
Catalytic Amount ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
Chemical Behavior ◽  
Model Compounds ◽  
Protection Method ◽  
Convenient Synthesis ◽  
Lignin Model ◽  
Convenient Preparation

Abstract Lignin, as the second most abundant biopolymer on earth, is one of the targets for plant biorefinery studies. Its complex chemical behavior is frequently studied by dimeric, trimeric, etc. model compounds, preferably with a β-O-4-type structure. In the present study, a convenient synthesis of a β-O-4-type trimeric model compound possessing a free syringylic hydroxyl has been investigated. Two key modifications were in focus: (1) Protection of the aliphatic hydroxyl groups of the starting phenolic dimer prior to the SN2 displacement reaction before introducing the syringylic moiety with 2,2-dimethoxypropane. (2) The hydroxymethylation step to introduce the full side chain moiety. When this reaction was performed in dioxane/water in the presence of a catalytic amount of KOH instead of K2CO3, the formation of a side product via dehydration was markedly reduced. In addition, a convenient method for introducing an α,β-epoxide structure in acetophenone is recommended.

scholarly journals Ball Milling’s Effect on Pine Milled Wood Lignin’s Structure and Molar Mass

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2223 ◽  
Author(s):  
Grigory Zinovyev ◽  
Ivan Sumerskii ◽  
Thomas Rosenau ◽  
Mikhail Balakshin ◽  
Antje Potthast
Keyword(s):  
Ball Milling ◽  
Mass Fraction ◽  
Molar Mass ◽  
Size Exclusion ◽  
Hydroxyl Groups ◽  
Wall Region ◽  
Sugar Composition ◽  
High Molar Mass ◽  
Milled Wood Lignin ◽  
Lignin Extraction

The effect of ball milling expressed as the yield of milled wood lignin (MWL) on the structure and molar mass of crude milled wood lignin (MWLc) preparation is studied to better understand the process’ fundamentals and find optimal conditions for MWL isolation (i.e., to obtain the most representative sample with minimal degradation). Softwood (loblolly pine) MWLc preparations with yields of 20–75% have been isolated and characterized based on their molar mass distribution (by Size Exclusion Chromatography (SEC)), hydroxyl groups of different types (31P NMR), methoxyl groups (HS-ID GC-MS), and sugar composition (based on methanolysis). Classical MWL purification is not used to access the whole extracted lignin. The results indicate that lignin degradation during ball milling occurs predominantly in the high molar mass fraction and is less pronounced in the low molar mass fraction. This results in a significant decrease in the Mz and Mw of the extracted MWLc with an increase in the yield of MWLc, but has only a very subtle effect on the lignin structure if the yield of MWLc is kept below about 55%. Therefore, no tedious optimization of process variables is necessary to achieve the required MWLc yield in this range for structural studies of softwood MWL. The sugar composition shows higher amounts of pectin components in MWLs of low yields and higher amounts of glucan and mannan in high-yield MWLs, confirming that lignin extraction starts from the middle lamella in the earlier stages of MWL isolation, followed by lignin extraction from the secondary wall region.

Construction of semi-fluorinated polyimides with perfluorocyclobutyl aryl ether-based side chains

2018 ◽  
Vol 9 (7) ◽  
pp. 920-930 ◽  
Author(s):  
Mingchen Jia ◽  
Mingtao Zhou ◽  
Yongjun Li ◽  
Guolin Lu ◽  
Xiaoyu Huang
Keyword(s):  
Side Chain ◽  
Side Chains ◽  
Aryl Ether ◽  
Fluorinated Polyimides ◽  
Controlled Topology

This article reports the construction of PFCB aryl ether-based polyimides with precisely controlled topology via side-chain chemistry.

scholarly journals DERA in Flow: Synthesis of a Statin Side Chain Precursor in Continuous Flow Employing Deoxyribose-5-Phosphate Aldolase Immobilized in Alginate-Luffa Matrix

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 137 ◽  
Author(s):  
Bianca Grabner ◽  
Yekaterina Pokhilchuk ◽  
Heidrun Gruber-Woelfler
Keyword(s):  
Renewable Resources ◽  
Continuous Flow ◽  
Ph Value ◽  
Continuous Process ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
Inexpensive Method ◽  
Reaction Conditions ◽  
Flow Process ◽  
Artery Disease

Statins, cholesterol-lowering drugs used for the treatment of coronary artery disease (CAD), are among the top 10 prescribed drugs worldwide. However, the synthesis of their characteristic side chain containing two chiral hydroxyl groups can be challenging. The application of deoxyribose-5-phosphate aldolase (DERA) is currently one of the most promising routes for the synthesis of this side chain. Herein, we describe the development of a continuous flow process for the biosynthesis of a side chain precursor. Design of experiments (DoE) was used to optimize the reaction conditions (pH value and temperature) in batch. A pH of 7.5 and a temperature of 32.5 °C were identified to be the optimal process settings within the reaction space considered. Additionally, an immobilization method was developed using the alginate-luffa matrix (ALM), which is a fast, simple, and inexpensive method for enzyme immobilization. Furthermore, it is non-toxic, biodegradable, and from renewable resources. The final continuous process was operated stable for 4 h and can produce up to 4.5 g of product per day.

New Host-Guest Polymeric System for Thermal Stability Enhancement of Electro Optic Effect

2002 ◽  
Vol 725 ◽  
Author(s):  
Seung Koo Park ◽  
Jung Yun Do ◽  
Jung-Jin Ju ◽  
Suntak Park ◽  
Myung-Hyun Lee
Keyword(s):  
Thermal Stability ◽  
Model Compound ◽  
Main Chain ◽  
Side Chain ◽  
Hydroxyl Groups ◽  
New Host ◽  
Polymer Main Chain ◽  
Electro Optic ◽  
Chromophore Concentration ◽  
Stability Enhancement

AbstractA new host-guest electro optic (EO) polymer, in which a chromophore can be reacted with the polymer main chain during poling to give the corresponding side-chain EO polymer, has been prepared for improving EO effect and its thermal stability. Polyisoimide (PII) synthesized from 2, 2-bis (4-aminophenyl) hexafluoropropane and oxydiphthalic anhydride and Disperse Red 1 (DR1) were used as a host and a guest, respectively. A model compound reaction and Infrared spectra of the host-guest film after annealing at various temperatures show that the reaction between the isoimide groups in PII and the hydroxyl groups in DR1 occurs around 140 °C. The glass transition temperatures of the resulting EO polyamic aicd ester-imide copolymer with 0, 10, 20 and 30 wt. % of chromophore concentration were 275, 219, 160, and 124 °C, respectively. The EO coefficient obtained at a wavelength of 1.55 νm was 5.3 and 10.5 pm/V from the EO polymer film with 20 and 30 wt. % DR1. The EO signals exhibited only a slight decay at high temperature due to the chemical reaction between the host and guest during poling.

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