Interpretation of long-chain structure in flexible homopolymers from dilute-solution dynamic properties measured in good solvents

1989 ◽  
Vol 22 (8) ◽  
pp. 3435-3442 ◽  
Author(s):  
Robert L. Sammler ◽  
John L. Schrag
Keyword(s):  
Dynamic Properties ◽  
Chain Structure ◽  
Dilute Solution ◽  
Long Chain

Interpretation of long-chain structure from dilute solution properties of ultrahigh molecular weight polymers

1992 ◽  
Vol 27 (5) ◽  
pp. 571-575 ◽  
Author(s):  
Maria Bercea ◽  
Silvia Ioan ◽  
Bogdan C. Simionescu ◽  
Cristofor I. Simionescu
Keyword(s):  
Molecular Weight ◽  
Chain Structure ◽  
Solution Properties ◽  
Dilute Solution ◽  
Dilute Solution Properties ◽  
Ultrahigh Molecular Weight ◽  
Long Chain

THE VISCOSITY – MOLECULAR WEIGHT RELATION FOR POLY-levo-2,3-BUTANEDIYL o-PHTHALATE

1948 ◽  
Vol 26b (12) ◽  
pp. 783-797
Author(s):  
R. W. Watson ◽  
N. H. Grace
Keyword(s):  
Molecular Weight ◽  
High Purity ◽  
Molecular Orientation ◽  
Degree Of Polymerization ◽  
Solution Viscosity ◽  
Dilute Solution ◽  
Molecular Weights ◽  
Complex Relation ◽  
End Group ◽  
Long Chain

The inherent viscosities of dilute solutions of acidic polyesters of high purity have been compared with number average molecular weights accurately determined by end-group titration. For unfractionated resins with a degree of polymerization from 2 to 11 [Formula: see text] the viscosity – molecular weight relation is linear in chloroform at 25 °C. Where [Formula: see text], K = 1.923 × 10−5 and β = 0.0176. For fractionated polyesters from DP 5 to 8, K = 1.959 × 10−6 and β = 0.0161. For unfractionated resins with a DP > 11, molecular weights increase more rapidly than inherent viscosities. Above [Formula: see text] for fractionated resins linearity is resumed, and the slope increases. Several attempts have been made to explain this complex relation. Apparently the short chains remain linear, and the formation of anisotropic fibers at a DP close to 100 establishes a degree of molecular orientation in the long-chain superpolyesters. Isomerization of levo-diol to the diastereoisomer during polycondensation is without effect on the dilute solution viscosity of the resulting resin. Preferential degradation of the longer chains is assumed to be partially responsible for the decreasing slope from DP 11 to 65. As yet it has not been possible to assess the roles played by changes in size distribution, and variation in solvation with increasing chain length, but the data point to a curved viscosity – molecular weight relation in chloroform at 25 °C.

Controlled Formation of Ag Nanoparticles by Means of Long-Chain Sodium Polyacrylates in Dilute Solution

2007 ◽  
Vol 129 (5) ◽  
pp. 1089-1094 ◽  
Author(s):  
Klaus Huber ◽  
Thomas Witte ◽  
Jutta Hollmann ◽  
Susanne Keuker-Baumann
Keyword(s):  
Ag Nanoparticles ◽  
Dilute Solution ◽  
Long Chain

Dynamic properties of solutions. Models for chain molecule dynamics in dilute solution

1970 ◽  
Vol 49 ◽  
pp. 182 ◽  
Author(s):  
W. H. Stockmayer ◽  
W. Gobush ◽  
Y. Chikahisa ◽  
D. K. Carpenter
Keyword(s):  
Dynamic Properties ◽  
Chain Molecule ◽  
Dilute Solution ◽  
Molecule Dynamics

scholarly journals Synthesis and Fluorescent Properties of Novel Mono- and Di-Substituted 1,8-Naphthalimide Derivatives at the C-4 Position

2017 ◽  
Author(s):  
Ying Fu ◽  
Xiao-Xiao Pang ◽  
Kui Wang ◽  
Zhi-Qiang Wang ◽  
Guan-Yu Li ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Chain Structure ◽  
Fluorescence Properties ◽  
Stacking Interactions ◽  
Fluorescent Properties ◽  
Enhanced Fluorescence ◽  
Pi Stacking ◽  
Molecular Core ◽  
Long Chain

A series of novel N-n-butyl-1,8-naphthalimide derivatives were synthesized via a three-step reaction involving nucleophilic substitution and acylation. All of the compounds were characterized by IR, 1H NMR, 13C NMR, MS, and elemental analysis, and the crystal structure of N-n-butyl-4-[N’,N’-bis(2`,4`-dichlorobenzoyl)ethylamino]-1,8-naphthalimide was determined. The π-π stacking interactions and hydrogen bonds between the two molecular core planes (naphthalimide ring) and the van der Waals forces between the flexible n-butyl groups resulted in a 3D long-chain structure. The UV-vis and fluorescence properties of the title compounds were investigated. The results indicated that the monosubstituted 1,8-naphthalimide derivatives bearing an electron-donating group on the benzene ring or a structure with a larger conjugative effect exhibited enhanced fluorescence properties.

scholarly journals Novel Nanocomposites Based on Bacterial Polyester/LDH-SDS Clay for Stem Cells Delivery in Modern Wound Healing Management

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4488
Author(s):  
Eugeniu Vasile ◽  
Ionut-Cristian Radu ◽  
Bianca Galateanu ◽  
Maria Rapa ◽  
Ariana Hudita ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Stem Cells ◽  
Wound Healing ◽  
Sodium Dodecyl ◽  
Young Modulus ◽  
Chain Structure ◽  
Nanocomposite Materials ◽  
Two Phases ◽  
Double Hydroxides ◽  
Long Chain

Nanocomposite materials based on poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBHV) and modified mineral clay layered double hydroxides (LDH-SDS) were explored as novel nanostructured materials for potential tissue engineering applications. The mineral clay inorganic phase was modified with an anionic long-chain structure of carbon atoms, such as sodium dodecyl sulfate, in order to increase the compatibility between the two phases. The melt intercalation method used for nanocomposite fabrication ensures a good dispersion of the modified LDH-SDS within the polymer matrix without using a toxic solvent (chloroform). The nanocomposites were found to have an intercalated/exfoliated structure with an enhanced Young modulus and increased stiffness. This could allow them to be considered for autologous stem cells dressings in the view of efficient wound healing applications.

scholarly journals A Tough, Water-Resistant, High Bond Strength Adhesive Derived from Soybean Meal and Flexible Hyper-Branched Aminated Starch

Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1352 ◽  
Author(s):  
Yi Zhang ◽  
Jieyu Zhang ◽  
Mingsong Chen ◽  
Jing Luo ◽  
Sheldon Q. Shi ◽  
...  
Keyword(s):  
Bond Strength ◽  
Soybean Meal ◽  
Water Resistance ◽  
Crosslinking Agent ◽  
Crosslinking Density ◽  
Chain Structure ◽  
High Bond ◽  
High Bond Strength ◽  
Branched Structure ◽  
Long Chain

Soybean meal (SM)-based adhesive exhibited a great potential to replace petroleum-derived ones to alleviate the energy crisis and eliminate carcinogenic formaldehyde. However, the bad water resistance (caused by low crosslinking density) and inherent brittleness of SM adhesive severely hindered its application. However, improving crosslinking density is generally accompanied by a toughness reduction of the adhesive. Herein, we developed a flexible long-chain starch with a hyper-branched structure (HD), and incorporated it with SM and a crosslinking agent to prepare a novel SM adhesive. Results showed that this adhesive exhibited both excellent water resistance and enhanced toughness. The wet bond strength of plywood fabricated using this adhesive was 354.5% higher than that of SM adhesive. These achievements are because introducing HD with hyper-branched groups enhanced crosslinking density, while HD’s flexible long-chain structure improved toughness of the adhesive. This HD can promote the development of tough and hydrophobic bio-based composites.

scholarly journals A further X-ray investigation of long chain compounds (n-hydrocarbon)

1928 ◽  
Vol 120 (785) ◽  
pp. 437-459 ◽  
Keyword(s):  
Crystal Structure ◽  
Stearic Acid ◽  
Single Crystals ◽  
Cross Section ◽  
Structure Factor ◽  
Chain Structure ◽  
Practical Reasons ◽  
X Ray ◽  
Chain Compounds ◽  
Long Chain

In a previous paper the writer has outlined the crystal structure of a number of long-chain compounds. One of the main results of this work was to show that the crystal molecules (chains) in all these substances can be represented as rods of definite cross section, the crystals being built up of bundles of these rods packed close together. A closer examination of the X-ray photographs of stearic acid gave the clue to the chain structure, and led to a general formula for the structure factor. It was then announced that a more detailed investigation of stearic acid was to follow. The choice of stearic acid was dictated entirely by practical reasons, no other well developed crystals of other similar substances being available at that time. But as it was obviously more desirable to study first the prototype of the long chain compounds, namely, the normal hydrocarbon, efforts were first made to find single crystals of these substances. The search was unexpectedly successful, and the present paper describes an attempt to interpret the results of the X-ray examination of a single crystal of the hydrocarbon C 29 H 60 .

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