scholarly journals Investigation of the polyurethane chain length influence on the molecular dynamics in networks crosslinked by hyperbranched polyester

Polymer ◽  
2006 ◽  
Vol 47 (20) ◽  
pp. 7207-7215 ◽  
Author(s):  
Przemyslaw Czech ◽  
Lidia Okrasa ◽  
Francoise Méchin ◽  
Gisele Boiteux ◽  
Jacek Ulanski
Keyword(s):  
Molecular Dynamics ◽  
Chain Length ◽  
Hyperbranched Polyester

THE "FOLDING" BEHAVIORS OF HOMOPOLYMERS WITH ONE END FIXED

2004 ◽  
Vol 18 (15) ◽  
pp. 2123-2139 ◽  
Author(s):  
BIN XUE ◽  
JUN WANG ◽  
WEI WANG
Keyword(s):  
Molecular Dynamics ◽  
Chain Length ◽  
Conformational Changes ◽  
Canonical Ensemble ◽  
Interaction Strength ◽  
Simulation Method ◽  
Dynamics Simulation ◽  
Radius Of Gyration ◽  
Native Conformation ◽  
Collapse Temperature

We study the "folding" behaviors of homopolymers with one end fixed. By using canonical ensemble molecular dynamics simulation method, we observe the conformational changes during folding processes. Long chains collapse to the helical nuclei, then regroup to helix from the free-end to form the compact conformations through the middle stages of helix-like coil and helix-like cone, while short chains do not apparently have the above mentioned middle stages. Through simulated annealing, the native conformation of homopolymer chain in our model is found to be helix. We show the relations between specific heat C v (T) and radius of gyration R g (T) as functions of temperature, chain length and the interaction strength, respectively. We find that these two quantities match well and can be combined to interpret the "folding" process of the homopolymer. It is found that the collapse temperature Tθ and the native-like folding temperature T f do not change with the chain length in our model, however the interaction strength affects the values of Tθ and T f .

Scrutiny of chain-length and N-terminal effects in α-helix folding: a molecular dynamics study on polyalanine peptides

2016 ◽  
Vol 35 (9) ◽  
pp. 1923-1935 ◽  
Author(s):  
Bhupesh Goyal ◽  
Anil Kumar ◽  
Kinshuk Raj Srivastava ◽  
Susheel Durani
Keyword(s):  
Molecular Dynamics ◽  
Chain Length ◽  
Α Helix

Molecular dynamics study of polyethylene chain non-isothermal crystallisation: effects of chain length and branch structure

2019 ◽  
Vol 45 (12) ◽  
pp. 967-974 ◽  
Author(s):  
Rui Gao ◽  
Li Zhao ◽  
Yunqi Shao ◽  
Zhen Liu ◽  
Xuelian He ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Chain Length ◽  
Isothermal Crystallisation

Thermomechanical properties of silica–epoxy nanocomposite modified by hyperbranched polyester: A molecular dynamics simulation

2021 ◽  
pp. 095400832110323
Author(s):  
Jianwen Zhang ◽  
Dongwei Wang ◽  
Lujia Wang ◽  
Wanwan Zuo ◽  
Xiaohua Ma ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Glass Transition ◽  
Epoxy Resin ◽  
Silica Surface ◽  
Thermomechanical Properties ◽  
Dynamics Simulation ◽  
Hyperbranched Polyester ◽  
Pure Epoxy ◽  
Epoxy Nanocomposite

In this article, pure epoxy resin and silica–epoxy nanocomposite models were established to investigate the effects of hyperbranched polyester on microstructure and thermomechanical properties of epoxy resin through molecular dynamics simulation. Results revealed that the composite of silica can improve the thermomechanical properties of nanocomposites, including the glass transition temperature, thermal conductivity, and elastic modulus. Moreover, the thermomechanical properties were further enhanced through chemical modification on the silica surface, where the effectiveness was the best through grafting hyperbranched polyester on the silica surface. Compared with pure epoxy resin, the glass transition temperature of silica–epoxy composite modified by silica grafted with hyperbranched polyester increased by 38 K. The thermal conductivity increased with the increase of temperature and thermal conductivity at room temperature increased to 0.4171 W/(m·K)−1 with an increase ratio of 94.3%. Young’s modulus, volume modulus, and shear modulus all fluctuated as temperature rise with a down overall trend. They increased by 44.68%, 29.52%, and 36.65%, respectively, when compared with pure epoxy resin. At the same time, the thermomechanical properties were closely related to the microstructure such as fractional free volume (FFV), mean square displacement (MSD), and binding energy. Silica surface modification by grafting hyperbranched polyester reduced the FFV value and MSD value most and strengthened the combination of silica and epoxy resin matrix the best, resulting in the best thermomechanical properties.

Studies of molecular dynamics in polyurethane networks with hyperbranched polyester Boltorn®H30 as a crosslinker

2007 ◽  
Vol 353 (47-51) ◽  
pp. 4293-4297 ◽  
Author(s):  
Lidia Okrasa ◽  
Przemyslaw Czech ◽  
Gisèle Boiteux ◽  
Francoise Méchin ◽  
Jacek Ulanski
Keyword(s):  
Molecular Dynamics ◽  
Hyperbranched Polyester ◽  
Polyurethane Networks
Sign in / Sign up

Export Citation Format

Share Document