scholarly journals Study on the Preparation and Application of Lignin-Derived Polycarboxylic Acids

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Ruiqi Wang ◽  
Bing Zhou ◽  
Zichen Wang
Keyword(s):  
Mechanical Properties ◽  
Main Product ◽  
Waterborne Polyurethane ◽  
Reaction Conditions ◽  
Polyurethane Elastomers ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Polycarboxylic Acids ◽  
Benzene Rings ◽  
Ft Ir

Lignin was oxidized by NaOCl, and the main product of the reaction was named lignin-derived polycarboxylic acids (LPCAs). The effect of the reaction conditions was studied. With the mix ratio [n(NaOCl)/m(lignin)] increasing, the content of carboxyl of LPCAs increased. When the reaction temperature or the reaction time increased, the content of carboxyl decreased in different degrees. After the oxidation by NaOCl, the content of hydroxyl and methoxyl of lignin decreased, and the molecular weight of lignin decreased as well. The FT-IR and 1H-NMR spectrum of lignin suggested that the benzene rings of lignin were disrupted after the oxidation. A possible mechanism of the oxidation of lignin by sodium hypochlorite is supposed to briefly demonstrate the reason that the benzene rings were disrupted and the content of carboxyl increased. Finally, an application example shows that LPCAs can strengthen the mechanical properties of waterborne polyurethane elastomers.

1H-NMR Analysis of Degree of Substitution in N,O-Carboxymethyl Chitosans from Various Chitosan Sources and Types

2012 ◽  
Vol 506 ◽  
pp. 158-161 ◽  
Author(s):  
A. Jaidee ◽  
Pornchai Rachtanapun ◽  
S. Luangkamin
Keyword(s):  
Chemical Structure ◽  
Carboxymethyl Chitosan ◽  
Degree Of Substitution ◽  
Resonance Spectroscopy ◽  
Nmr Analysis ◽  
Reaction Conditions ◽  
H Nmr ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Chitosan Oligomer ◽  
Ft Ir

N,O-Carboxymethyl chitosans were synthesized by the reaction between shrimp, crab and squid chitosans with monochloroacetic acid under basic conditions at 50°C. The mole ratio of reactants was obtained from various reaction conditions of shrimp chitosan polymer and oligomer types. The mole ratio 1:12:6 of chitosan:sodium hydroxide:monochloroacetic acid was used for preparing carboxymethyl of chitosan polymer types while carboxymethyl of chitosan oligomer types were used the mole ratio 1:6:3 of chitosan:sodium hydroxide:monochloroacetic acid. The chemical structure was analyzed by fourier transformed infrared spectroscopy (FT-IR) and proton nuclear magnatic resonance spectroscopy (1H-NMR). The FT-IR was used for confirm the insertion of carboxymethyl group on chitosan molecules. The 1H-NMR was used for determining the degree of substitution (DS) of carboxymethylation at hydroxyl and amino sites of chitosans. Carboxymethyl chitosan samples had the total DS of carboxymethylation ranging from 1.0-2.2. The highest of DS of carboxymethylation was from shrimp chitosan oligomer type.

An Unparalleled H-bonding and Ion-bonding Crosslinked Waterborne Polyurethane with Super Toughness and Unprecedented Fracture Energy

2021 ◽  
Author(s):  
Yuan Yao ◽  
Bo Liu ◽  
Ziyang Xu ◽  
Jianhai Yang ◽  
Wenguang Liu
Keyword(s):  
Mechanical Properties ◽  
Fracture Energy ◽  
Waterborne Polyurethane ◽  
Self Healing ◽  
Polyurethane Elastomers

Self-healing polyurethane elastomers have been extensively studied; however, developing an eco-friendly self-healable waterborne polyurethane (WPU) with exceptional mechanical properties remains a great challenge. Herein, we report healable, and highly tough...

scholarly journals Synthesis of New Imidazolidine and Tetrahydropyrimidine Derivatives

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Hamid Beyzaei ◽  
Reza Aryan ◽  
Zahra Keshtegar
Keyword(s):  
Ring Opening ◽  
Reaction Times ◽  
Reaction Conditions ◽  
Ir Spectrometry ◽  
H Nmr ◽  
Chemical Structures ◽  
Thioamide Group ◽  
Solvent Free Conditions ◽  
Ft Ir ◽  
C Nmr

Synthesis of new imidazolidine and tetrahydropyrimidine derivatives 3a, b and 4a–c as cyclic 1,3-diamines under two reaction conditions (A and B) is described. Under reaction conditions-A, a suspension of (E)-2-cyano-2-(oxazolidin-2-ylidene)ethanethioamide 1 (1 eq.) and diaminoalkanes 2a–e (2 eq.) in absolute ethanol is heated under reflux for 16–22 h to afford 3a, b and 4a–c. Alternatively, under reaction conditions-B, a solution of thioamide 1 (1 eq.) in diaminoalkanes 2a–e (3 eq.) is stirred under solvent-free conditions at room temperature for 3 days to give desired products. Reaction conditions-A for having higher yields, shorter reaction times, and required less diamines is more effective than reaction conditions-B. Oxazolidine ring opening is observed by reacting compound 1 with all of the diamines 2a–e, but the thioamide group only reacts with nonbulky diamines 2a, b. The chemical structures of novel compounds were confirmed by 1H NMR, 13C NMR, elemental analysis, and FT-IR spectrometry.

Preparation and Interaction of Modified PHS and CMC Liquid Composites

2014 ◽  
Vol 1035 ◽  
pp. 204-211 ◽  
Author(s):  
Xiao Ling Xu ◽  
Min Zhang ◽  
Ji Qing Song ◽  
Wen Qing He
Keyword(s):  
Molecular Dynamics ◽  
Polyethylene Glycol ◽  
Main Chain ◽  
Composite Films ◽  
Interfacial Interaction ◽  
Structure Characterization ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Ft Ir

Novel liquid composites were successfully prepared by blending copolymer (PEG/PHS) and carboxymethyl cellulose (CMC) in this work. PEG/PHS was achieved by introducing polyethylene glycol (PEG) into the main chain of poly hexanediol succinic (PHS). The results showed that the structure characterization of PEG/PHS was displayed in 1H NMR spectrum. The interaction existed between PEG/PHS and CMC which was validated in FT-IR and SEM. This conjecture was simulated by molecular dynamics under the software YASARA. Because of the existence of interfacial interaction, composites films kept good thermal performance and the flexibility of composite films was greatly improved.

scholarly journals New Hybrid Polyurea-Polyurethane Elastomers with Antistatic Properties and an Influence of Various Additives on Their Physicochemical Properties

Molecules ◽  
2021 ◽  
Vol 26 (19) ◽  
pp. 5778
Author(s):  
Szymon Kosiński ◽  
Marcin Gonsior ◽  
Piotr Krzyżanowski ◽  
Iwona Rykowska
Keyword(s):  
Mechanical Properties ◽  
Surface Defects ◽  
Reference Sample ◽  
High Strength ◽  
Hybrid Coatings ◽  
Polyurethane Elastomers ◽  
Existing Structures ◽  
Ft Ir ◽  
Further Development ◽  
Weathering Effects

Polyurea is a synthetic high-strength elastomeric material that can be sprayed as a coating over existing structures in order to protect against weathering effects. It is ideal for anti-corrosion protection and is characterized by excellent mechanical properties and adhesion to various surfaces. Further development of this technology may allow obtaining new coatings with improved antistatic properties, which would be an excellent alternative compared to used antistatic epoxy paints. This paper will examine the influence of tetraalkylammonium salt (1), potassium hexafluorophosphate solution (2) and imidazolium-based ionic liquid (3) on the improvement of antistatic properties of the polyurea-polyurethane coatings. In addition, the modified samples were also verified in terms of changes in mechanical properties and the appearance of functional groups other than in the reference sample, as well as surface defects that may arise due to incompatibility of the antistatic additive with the polymer matrix. In order to obtain information about the properties mentioned above, the electrical resistance was determined, the tensile strength and elongation were measured, FT-IR spectra were made, and images were taken with the use of scanning electron microscopy. The conducted research showed that the antistatic properties of the tested hybrid coatings could be improved, but their use may be associated with certain limitations that should be taken into account when designing such materials.

scholarly journals A novel DOPO-g-KH550 modification wood fibers and its effects on the properties of composite phenolic foams

2018 ◽  
Vol 20 (2) ◽  
pp. 47-53 ◽  
Author(s):  
Yufeng Ma ◽  
Xiang Geng ◽  
Xi Zhang ◽  
Chunpeng Wang ◽  
Fuxiang Chu
Keyword(s):  
Mechanical Properties ◽  
Phenolic Resin ◽  
Wood Fiber ◽  
Treated Wood ◽  
Comprehensive Analysis ◽  
Wood Fibers ◽  
H Nmr ◽  
Interfacial Compatibility ◽  
Ft Ir ◽  
Diffraction Peaks

Abstract A novel 9, 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) graft γ-amino propyl triethoxy silane (KH550) was synthesized and introduced on the surface of wood fiber. Finally DOPO-g-KH550 treated wood fiber (DKTWF) was used to prepare DKTWF composite phenolic foams (DKTWFCPF). The structures of DOPO-g- KH550 was acknowledged by Fourier transform infrared (FT-IR) and nuclear magnetic resonance (1H-NMR). The structures of DKTWF were confirmed by FT-IR. Compared with wood fiber, the diffraction peaks’ position was basically unchanged, but the crystallinity was slightly increased and thermal stability were dramatically improved, T5% and Tmax increased by 21.9o and 36.1o respectively. But the char yield (800o) was slightly reduced. With the dosage of DKWF, there were different degrees of improvement including the mechanical properties, flame retardancy and microstructure of DKTWFCPF. Comprehensive analysis, the interfacial compatibility was significantly improved between DKTWF and phenolic resin, and the suitable content of DKTWF was 4%.

Odd-Carbon Alkyl-Substituent Effect on Liquid Crystalline Properties of Discotic Hexa-Peri-Hexabenzocoronene Molecule

2011 ◽  
Vol 239-242 ◽  
pp. 3358-3361 ◽  
Author(s):  
Xu Ying Liu ◽  
Yu Jiang ◽  
Wen Guang Wang ◽  
Jia Ling Pu
Keyword(s):  
Differential Scanning Calorimetry ◽  
Self Assembly ◽  
Grignard Reagent ◽  
Liquid Crystalline ◽  
Alkyl Substituent ◽  
Electronic Interaction ◽  
Scanning Calorimetry ◽  
Nmr Spectrum ◽  
H Nmr ◽  
Benzene Rings

Hexa-peri-Hexabenzocoronene (HBC), as the smaller graphene fragment consisting of 13 fused benzene rings, possesses a strong tendency to stack together via π-electronic interaction. In this paper, the 1,2-(4-bromomethyl-1-yl) acetylene was alkylated by Grignard reagent to form corresponding 1,2-bis(p-pentadecanylphenyl)acetylene. Cobalt(0)-catalyzed cyclotrimerization was carried out to give hexaphenylbenzene analogue. This step was followed by intramolecular cyclodehydrogenation to yield the desired product HBC-C15. The identity and purity of the new compound was confirmed by UV-vis spectrometer and 1H NMR spectrum. Its thermal behavior and self-assembly were studied by differential scanning calorimetry and polarizing optical microscopy.

Preparation of Novel Liquid Crystal Material with Trifluoromethyl Substitutent

2013 ◽  
Vol 785-786 ◽  
pp. 690-692
Author(s):  
Yong Ming Zhang ◽  
Yi Wei Wang ◽  
Mei Zhang ◽  
Jian Fang Liu ◽  
Jie Si ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Coupling Reaction ◽  
Sonogashira Coupling ◽  
Reaction Conditions ◽  
H Nmr ◽  
Crystal Material ◽  
Liquid Crystal Material ◽  
Display Area ◽  
Sonogashira Coupling Reaction ◽  
Ft Ir

The liquid crystal material with trifluoromethyl substitutent is a very important liquid crystal monomer to combine mixture in the application of display area. In this paper, a kind of liquid crystal material with trifluoromethyl substitutent was synthesized by traditional method of Sonogashira coupling reaction, the reaction mechanism and reaction conditions were then obtained. In addition, the synthesized compound was characterized by FT-IR and1H-NMR to confirm the consistent structure with target compound.

SYNTHESIS, AND SURFACE-ACTIVE PROPERTIES OF PALM FATTY ACID AND 1(2-HYDROXYETHYL PIPERAZINE)-BASED ESTERAMIDE QUAT

2007 ◽  
Vol 14 (06) ◽  
pp. 1129-1133 ◽  
Author(s):  
SHILPI MISHRA ◽  
V. K. TYAGI
Keyword(s):  
Fatty Acids ◽  
Reaction Conditions ◽  
Molar Ratios ◽  
H Nmr ◽  
Surface Active Properties ◽  
Optimum Reaction ◽  
Ft Ir ◽  
Surface Active ◽  
And Performance ◽  
Hydroxyethyl Piperazine

In this study, an attempt has been made to synthesize esteramide quat by esterification of palm fatty acids with 1(2-hydroxyethyl piperazine) followed by quaternization with dimethyl sulphate (DMS). The optimum reaction conditions for esterification of palm fatty acids and 1(2-hydroxyethyl piperazine) were found to be 170°C reaction temperature and 150 mmHg pressure. The obtained esteramide was subjected to quaternization with different molar ratios of DMS. The consequences revealed that esteramide to DMS ratio of 1 : 0.95 and duration of quaternization for 2 h yielded esteramide quat of maximum cationic content, i.e., 64.9%. The instrumental analysis, viz. FT-IR, 1 H NMR, 13 C NMR verified the esterification and subsequent quaternization of the obtained esteramide quat. Furthermore, the surface-active and performance properties of synthesized esteramide quat were also evaluated.

Preparation of Terephthalic Acid (TPA) and Dioctyl Terephthalate (DOTP) by Anthracite's Alkali Oxygen Oxidation

2014 ◽  
Vol 541-542 ◽  
pp. 95-99
Author(s):  
Kun Du ◽  
Ming Lei Lian ◽  
Zhi Fang Fan ◽  
Yu Li
Keyword(s):  
Aqueous Solution ◽  
Terephthalic Acid ◽  
Potassium Hydroxide ◽  
Water Soluble ◽  
Reaction Conditions ◽  
H Nmr ◽  
Optimum Reaction ◽  
Final Yield ◽  
Ft Ir ◽  
Oxygen Oxidation

TPA was synthesized by a two step reaction. Firstly, water-soluble coal acids (CA) was obtained by oxygen-oxidation at 260°C in all aqueous solution of potassium hydroxide, and then crud TPA was got by isomerization of the CA with the existence of CdCO3 catalyst and CO2 pressure. The optimum reaction conditions to get crude TPA were 4% amount of CdCO3 catalyst, and reacted at 420°C with initial 3.0MPa CO2 pressure. Pure TPA was obtained by a separation step and the yield of pure TPA is 37.16% (based on CA). Furthermore, DOTP was synthesized by the refined TPA and isooctanol. The influence of mole ratio of TPA and isooctanol, amount of catalyst and reaction time on the final yield of DOTP were discussed. The purity of TPA was detected by HPLC and DOTP was detected by FT-IR, 1H-NMR to get confirmatory results.

Sign in / Sign up

Export Citation Format

Share Document