Low Molecular-Mass Gelators with Diyne Functional Groups and Their Unpolymerized and Polymerized Gel Assemblies

2003 ◽  
Vol 15 (15) ◽  
pp. 2879-2888 ◽  
Author(s):  
Mathew George ◽  
Richard G. Weiss
Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 612
Author(s):  
Stoyan I. Karakashev ◽  
Nikolay A. Grozev ◽  
Khandjamts Batjargal ◽  
Onur Guven ◽  
Orhan Ozdemir ◽  
...  

Can the critical coalescence concentration (CCC) of the flotation frothers be predictable? What is the relation between their molecular structure and their CCC values? A literature survey found specific correlations between the hydrophilic-lipophilic balances (HLB) and HLB/Mw (where Mw stands for the molecular mass) of homologue series of frothers and their CCC values, but the results are invalid when the molecule’s functional groups change. For this reason, 37 frothers with known values of CCC were analyzed. The CCC values of seven frothers were determined, and the rest were taken from the literature. The frothers were subdivided in homologue series with an increasing number of the carbon atoms with an account for the type and the location of the functional group, thus deriving three types of correlations lnCCC = f(HLB) applicable for: (i) alcohols; (ii) propylene glycols alkyl ethers and propylene glycols; (iii) ethylene glycols alkyl ethers. The average accuracy of these correlations between CCC and HLB is 93%.


1979 ◽  
Vol 44 (8) ◽  
pp. 2338-2343 ◽  
Author(s):  
Jindřiška Maternová ◽  
Karel Setínek

Sorption of organic amines from various solvents on standard and macroporous sulphonated styrene-divinylbenzene copolymers has been studied. The amount sorbed depends above all on the molecular mass (size) of sorbate, but its chemical affinity (basicity) toward polymer functional groups plays a role, too. The solvent and copolymer crosslinking effects are in mutual relation and are less pronounced. In addition to the interaction of the sorbate with sulphonic acid groups of the polymer, the sorbate dissolves also in the polymer.


INEOS OPEN ◽  
2020 ◽  
Author(s):  
A. S. Torozova ◽  
◽  
E. S. Serkova ◽  
I. Yu. Krasnova ◽  
A. A. Korolkova ◽  
...  

A hyperbranched pyridylphenylene polymer with the weight average molecular mass of 56000 Da is synthesized for the first time from an AB2 monomer bearing one diene and two internal triple bonds. The introduction of a linear AB comonomer into the reaction system leads to an increase in the yield of the polymer which has the weight average molecular mass of 21400 Da. Due to the limited degree of intramolecular cyclization, the high content of functional groups facilitates the formation of defect-free structures and provides an opportunity to modify the resulting polymers.


2021 ◽  
Vol 2131 (4) ◽  
pp. 042045
Author(s):  
F Burkhev ◽  
H Kushiev ◽  
T Juraev

Abstract Our article describes in the results of the research the polymerization of the residual (brown tint) after the separation of useful cabocylic compounds (indene) from the composition of one of the important fractions of heavy pyrolysis oil (indene and its homologues), which are considered to be a brownish product formed on the basis of natural gas pyrolysis, and the molecular mass and physical chemical. As a result of the analysis of the infrared (IR), it was known that the product contains functional groups (-C=C-) with a polymerizing property, along with an aromatic ring, and the polymer is made up of a mixture of isomers of polyvinyl toluene. The molecular mass of the polymer (MM) in the viscometric method was determined as the best solvent of benzene in the process of maturation, the macromolecular mass and the degree of polymerization (p) were determined as a result of the studies conducted.


1971 ◽  
Author(s):  
Warren G. Bennis ◽  
Michael Beer ◽  
Gerald R. Pieters ◽  
Alan T. Hundert ◽  
Samuel H. Marcus ◽  
...  

1990 ◽  
Vol 63 (01) ◽  
pp. 067-071 ◽  
Author(s):  
Joan C Castellote ◽  
Enric Grau ◽  
Maria A Linde ◽  
Nuria Pujol-Moix ◽  
Miquel LI Rutllant

SummaryIncreasing evidence suggests the involvement of leukocytes in the fibrinolytic system. Monocytes secrete pro-urokinase (Grau, Thromb Res 1989; 53: 145) and it has been shown that these cells have specific receptors for urokinase and plasminogen (Miles, Thromb Haemostas 1987; 58: 936). The aim of this study was to analyse the presence of plasminogen activator inhibitor(s) in platelet-free suspensions of human peripheral blood monocytes and polymorphonuclear leukocytes (PMN). SDS-PAGE and reverse fibrin autography showed an inhibitory band of 50 kDa in the monocyte extracts (Triton X-100) but not in the PMN extracts. Urokinase (u-PA) was mixed with increasing amounts of monocyte extract for 10 min and the mixtures were added to 125Ifibrin coated wells containing plasminogen. A dose-dependent decrease in the u-PA fibrinolytic activity was observed. The amount of inhibition increased when the monocyte releasates were preincubated with u-PA (40% inhibition after 5 min preincubation and 80% after 15 min), indicating a direct interaction between this activator and an inhibitor(s). After SDS-PAGE of monocyte extracts, immunoblotting and peroxidase staining identified both PAI1 and PAI2, with an apparent molecular weight of 47-50 kDa. Monocyte-associated PAI1 formed complexes with single chain t-PA with a molecular mass 50 kDa higher than the molecular mass of the free PAI1. However, a significant amount of PAI remained unbound to t-PA. This inactive PAI1 could have come from a rapid inactivation of the primary active PAI1. These PAI1 and PAI2 detected in human monocytes may be transcendent in the regulation of the fibrinolytic system.


2016 ◽  
Vol 19 (2) ◽  
pp. 93-100
Author(s):  
Lalita El Milla

Scaffolds is three dimensional structure that serves as a framework for bone growth. Natural materials are often used in synthesis of bone tissue engineering scaffolds with respect to compliance with the content of the human body. Among the materials used to make scafffold was hydroxyapatite, alginate and chitosan. Hydroxyapatite powder obtained by mixing phosphoric acid and calcium hydroxide, alginate powders extracted from brown algae and chitosan powder acetylated from crab. The purpose of this study was to examine the functional groups of hydroxyapatite, alginate and chitosan. The method used in this study was laboratory experimental using Fourier Transform Infrared (FTIR) spectroscopy for hydroxyapatite, alginate and chitosan powders. The results indicated the presence of functional groups PO43-, O-H and CO32- in hydroxyapatite. In alginate there were O-H, C=O, COOH and C-O-C functional groups, whereas in chitosan there were O-H, N-H, C=O, C-N, and C-O-C. It was concluded that the third material containing functional groups as found in humans that correspond to the scaffolds material in bone tissue engineering.


TAPPI Journal ◽  
2013 ◽  
Vol 12 (1) ◽  
pp. 37-43 ◽  
Author(s):  
HANNU PAKKANEN ◽  
TEEMU PALOHEIMO ◽  
RAIMO ALÉN

The influence of various cooking parameters, such as effective alkali, cooking temperature, and cooking time on the formation of high molecular mass lignin-derived and low molecular mass carbohydrates-derived (aliphatic carboxylic acids) degradation products, mainly during the initial phase of softwood kraft pulping was studied. In addition, the mass transfer of all of these degradation products was clarified based on their concentrations in the cooking liquor inside and outside of the chips. The results indicated that the degradation of the major hemicellulose component, galactoglucomannan, typically was dependent on temperature, and the maximum degradation amount was about 60%. In addition, about 60 min at 284°F (140°C) was needed for leveling off the concentrations of the characteristic reaction products (3,4-dideoxy-pentonic and glucoisosaccharinic acids) between these cooking liquors. Compared with low molecular mass aliphatic acids, the mass transfer of soluble lignin fragments with much higher molecular masses was clearly slower.


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