Coupling Agents for Certain Types of Fluoroelastomers

1978 ◽  
Vol 51 (5) ◽  
pp. 897-906 ◽  
Author(s):  
J. W. Martin ◽  
T. V. Braswell ◽  
H. E. Green
Keyword(s):  
Molecular Weight ◽  
Coupling Agent ◽  
Coupling Agents ◽  
Low Molecular Weight ◽  
Mechanical And Thermal Properties ◽  
Effective Performance ◽  
Base Polymer ◽  
Service Conditions ◽  
Carbon Fillers ◽  
First Time

Abstract From the data presented in this paper, it is concluded that fillers can be coupled with certain types of fluoroelastomer base polymers. A useful coupling agent must have mechanical and thermal properties at least equivalent to the base polymer in order to provide an improvement in properties for the compound under extreme service conditions. For the particular case of peroxide-curable fluoroelastomers and carbon fillers, hydroxy-terminated low-molecular-weight polybutadienes with high 1,2-microstructure appear to be good coupling agents. Care must be exercised in selecting the peroxide level to obtain a high crosslink density of the coupling agent while retaining rubberlike properties of the compound. This type of polybutadienediol has a relatively high number of reactive vinyl groups (approximately 20 per molecule) and relatively high molecular weight. Based upon the hypotheses presented in this paper, that coupling between carbon black and fluoroelastomers has been demonstrated for the first time, both higher molecular weight and multifunctionality of the polybutadienediol are viewed as important characteristics for effective performance.

Graft modification in bamboo cellulose nanofibrils: An effective option to improve compatibility and tunable surface energy

2021 ◽  
Author(s):  
Carlos Alejandro Rodríguez-Ramírez ◽  
Alain Dufresne ◽  
Norma Beatriz D'Accorso ◽  
Nancy Garcia
Keyword(s):  
Molecular Weight ◽  
Thermal Properties ◽  
Cellulose Nanofibrils ◽  
Value Added ◽  
Xrd Analysis ◽  
Low Molecular Weight ◽  
Mechanical And Thermal Properties ◽  
Graft Modification ◽  
Effective Option ◽  
20 Nm

Abstract In this work, from an endemic and non-significant value-added bamboo argentine, nanofibrils (CNFs) of 20 nm in width were obtained. These nanofibrils were chemical modified in surface with three simple steps using a noncommercial low molecular weight polylactic acid. The success of modification was confirmed by FTIR, TGA, DSC and XRD analysis. The modified nanofibrils were taken up for changing surface properties in films based on commercial PLA. The results show that dispersive (γ D/S) component of films increase of 34.7 mN/m to 36.1 mN/m after the addition of modified nanofibrils from 2 to 5% in formulation of the films, comparing with a physical blend. Interesting others result in physical, mechanical, and thermal properties of the nanocomposites, were reported.

scholarly journals Synthesis and deposition of a Tröger’s base polymer on the electrode surface for potentiometric detection of a neuroblastoma tumor marker metabolite

2016 ◽  
Vol 52 (80) ◽  
pp. 11991-11994 ◽  
Author(s):  
T. V. Shishkanova ◽  
M. Havlík ◽  
M. Dendisová ◽  
P. Matějka ◽  
V. Král
Keyword(s):  
Molecular Weight ◽  
Tumor Marker ◽  
Electrode Surface ◽  
Innovative Approach ◽  
Low Molecular Weight ◽  
Potentiometric Detection ◽  
Neuroblastoma Tumor ◽  
Troger's Base ◽  
Base Polymer

We propose an innovative approach to detect a low molecular weight metabolite of neuroblastoma.

scholarly journals Neuroprotective Metabolites from Vietnamese Marine Derived Fungi of Aspergillus and Penicillium Genera

Marine Drugs ◽  
2020 ◽  
Vol 18 (12) ◽  
pp. 608
Author(s):  
Elena V. Girich ◽  
Anton N. Yurchenko ◽  
Olga F. Smetanina ◽  
Phan Thi Hoai Trinh ◽  
Ngo Thi Duy Ngoc ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Secondary Metabolites ◽  
Cell Viability ◽  
Chemical Structure ◽  
Aspergillus Terreus ◽  
Marine Fungi ◽  
2D Nmr ◽  
Natural Source ◽  
Low Molecular Weight ◽  
First Time

Low molecular weight secondary metabolites of marine fungi Aspergillus flocculosus, Aspergillus terreus and Penicillium sp. from Van Phong and Nha Trang Bays (Vietnam) were studied and a number of polyketides, bis-indole quinones and terpenoids were isolated. The structures of the isolated compounds were determined by 1D and 2D NMR and HR-ESI-MS techniques. Stereochemistry of some compounds was established based on ECD data. A chemical structure of asterriquinone F (6) was thoroughly described for the first time. Anthraquinone (13) was firstly obtained from a natural source. Neuroprotective influences of the isolated compounds against 6-OHDA, paraquat and rotenone toxicity were investigated. 4-Hydroxyscytalone (1), 4-hydroxy-6-dehydroxyscytalone (2) and demethylcitreoviranol (3) have shown significant increasing of paraquat- and rotenone-treated Neuro-2a cell viability and anti-ROS activity.

scholarly journals Cabozantinib and apixaban: an hitherto unreported interaction

2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Daniele Santini ◽  
Fabrizio Citarella ◽  
Bruno Vincenzi ◽  
Marco Russano ◽  
Giuseppe Tonini ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Renal Cell Carcinoma ◽  
Oral Anticoagulant ◽  
Low Molecular Weight Heparin ◽  
New Drugs ◽  
Low Molecular Weight ◽  
Direct Oral Anticoagulant ◽  
Anticancer Treatment ◽  
Pharmaceutical Agents ◽  
First Time

Abstract The use of direct oral anticoagulant in cancer patients is an emerging issue, which seems to be an alternative to low molecular weight heparin. Every year several new drugs are approved as anticancer treatment with possible drug-drug interaction with other drugs such as oral anticoagulant. We describe, for the first time, a case of neutropenia and thrombocytopenia in a patient in treatment with cabozantinib, a novel anticancer treatment used in metastatic renal cell carcinoma, and apixaban with promptly resumption of the toxicity after the interruption of cabozantinib. This case suggest a possible interaction between these two pharmaceutical agents, which merit caution considering the spreading of the two drugs.

Detection of cellulase inhibitor in the wheat bran culture of Aspergillus terreus

1981 ◽  
Vol 27 (12) ◽  
pp. 1334-1340 ◽  
Author(s):  
S. N. Sinha ◽  
B. L. Ghosh ◽  
S. N. Ghose
Keyword(s):  
Molecular Weight ◽  
Wheat Bran ◽  
Filter Paper ◽  
Aspergillus Terreus ◽  
Defined Medium ◽  
Low Molecular Weight ◽  
Chemically Defined Medium ◽  
Plant Origin ◽  
First Time ◽  
Hydrolysis Of

The presence of a cellulase inhibitor in the wheat bran culture of a fungus is reported for the first time. The inhibitor has a low molecular weight and is relatively stable to heat. It is absent from wheat bran and is not produced in a chemically defined medium. Unlike cellulase inhibitors of plant origin, this inhibitor is not a polyphenol. It inhibits the hydrolysis of cotton to a greater degree than that of filter paper or carboxymethylcellulose. In addition to inhibiting Aspergillus terreus cellulase, it also inhibits a variety of commercial cellulases.

Influence of two novel compatibilizers on the properties of LDPE/organoclay nanocomposites

2014 ◽  
Vol 34 (1) ◽  
pp. 75-83 ◽  
Author(s):  
Haydar U. Zaman ◽  
Dalour Hossen Beg
Keyword(s):  
Molecular Weight ◽  
Tensile Modulus ◽  
Low Molecular Weight ◽  
Mechanical And Thermal Properties ◽  
Scanning Calorimetry ◽  
Melt Mixing ◽  
Nucleation Effect ◽  
Transmission Electron ◽  
Linear Viscoelastic ◽  
Silicate Clay

Abstract In the present investigation, low density polyethylene (LDPE)/organoclay nanocomposites with various clay contents (1–7 wt%) were prepared via a melt mixing technique, using two different compatibilizers with various contents; low molecular weight trimethoxysilyl-modified polybutadiene (Organosilane) and low molecular weight oxidized polyethylene (OxPE). The effects of incorporation of compatibilizers and clay contents on the mechanical and thermal properties of the nanocomposites were investigated. The dispersibility of silicate clay in the nanocomposites was investigated by transmission electron microscopy (TEM). It was found that organosilane yielded better clay dispersion and a more exfoliated structure compared with the OxPE. Rheological behavior of the samples was examined by a dynamic oscillatory rheometer in the linear viscoelastic region. The organosilane compatibilized system conferred higher tensile strength, yield strength and tensile modulus than those of an uncompatibilized system, and even higher than those of the OxPE compatibilized case. The crystallization behaviors of uncompatibilized and compatibilized nanocomposites were investigated using differential scanning calorimetry (DSC). DSC results indicated that the addition of compatibilizers increased the crystallization temperature (Tc) as a result of heterogeneous nucleation effect of clay on LDPE.

Low molecular weight gels: potential in remediation of crude oil spillage and recovery

RSC Advances ◽  
2016 ◽  
Vol 6 (58) ◽  
pp. 53415-53420 ◽  
Author(s):  
Ch. Siva Kesava Raju ◽  
Bhaskar Pramanik ◽  
Tanmoy Kar ◽  
Peddy V. C. Rao ◽  
Nettem V. Choudary ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Crude Oil ◽  
Potential Application ◽  
Crude Oils ◽  
Low Molecular Weight ◽  
Oil Spillage ◽  
Wide Range ◽  
First Time

A molecular gelator which has strong gelation ability for different crude oils (light to heavy crudes), and a wide range of refinery products is reported for the first time for its potential application in oil spillage/recovery.

Preparation of SiBCN Microtubes from Melt-Spinnable Polymers

2008 ◽  
Vol 368-372 ◽  
pp. 926-928 ◽  
Author(s):  
Laura Gottardo ◽  
Samuel Bernard ◽  
Marie Paule Berthet ◽  
Philippe Miele
Keyword(s):  
Molecular Weight ◽  
Tensile Strength ◽  
Nitrogen Atmosphere ◽  
Low Molecular Weight ◽  
Ceramic Fibers ◽  
Preceramic Polymers ◽  
Flexible Form ◽  
First Time

SiBCN microtubes were prepared for the first time by spinning a low molecular weight preceramic polymers of boron-modified polyvinylsilazanes into green fibers ~30 m in diameter which were subsequently thermolyzed under a nitrogen atmosphere. Hollow SiBCN ceramic fibers black colored, of flexible form, ~20 m in diameter and 0.8GPa in tensile strength were produced.

In situ formation of AuNPs using fatty N-acylamino hydrazide organogelators as templates

2019 ◽  
Vol 43 (1) ◽  
pp. 295-303 ◽  
Author(s):  
Renata Ongaratto ◽  
Naiane Conte ◽  
Caroline R. Montes D’Oca ◽  
Rafael C. Brinkerhoff ◽  
Caroline Pires Ruas ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Gold Nanoparticles ◽  
Low Molecular Weight ◽  
In Situ Formation ◽  
First Time

This work reports, for the first time, the synthesis of new fatty N-acylamino hydrazides and demonstrates the activity of these compounds as low-molecular-weight organic gelators and templates for preparation of gold nanoparticles (AuNPs).

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