Predictions of the ability of solution dynamics experiments to characterize long-chain structure in flexible homopolymers

1988 ◽  
Vol 21 (11) ◽  
pp. 3273-3285 ◽  
Author(s):  
Robert L. Sammler ◽  
John L. Schrag
1992 ◽  
Vol 27 (5) ◽  
pp. 571-575 ◽  
Author(s):  
Maria Bercea ◽  
Silvia Ioan ◽  
Bogdan C. Simionescu ◽  
Cristofor I. Simionescu

Author(s):  
Ying Fu ◽  
Xiao-Xiao Pang ◽  
Kui Wang ◽  
Zhi-Qiang Wang ◽  
Guan-Yu Li ◽  
...  

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.


Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4488
Author(s):  
Eugeniu Vasile ◽  
Ionut-Cristian Radu ◽  
Bianca Galateanu ◽  
Maria Rapa ◽  
Ariana Hudita ◽  
...  

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.


Polymers ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1352 ◽  
Author(s):  
Yi Zhang ◽  
Jieyu Zhang ◽  
Mingsong Chen ◽  
Jing Luo ◽  
Sheldon Q. Shi ◽  
...  

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.


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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