Arresting Elevated-Temperature Creep and Achieving Full Cross-Link Density Recovery in Reprocessable Polymer Networks and Network Composites via Nitroxide-Mediated Dynamic Chemistry

2021 ◽  
Vol 54 (3) ◽  
pp. 1452-1464
Author(s):  
Lingqiao Li ◽  
Xi Chen ◽  
Kailong Jin ◽  
Mohammed Bin Rusayyis ◽  
John M. Torkelson
Keyword(s):  
Elevated Temperature ◽  
Polymer Networks ◽  
Cross Link ◽  
Temperature Creep ◽  
Link Density ◽  
Cross Link Density

scholarly journals From Natural Oils to Epoxy Resins: A New Paradigm in Renewable Performance Materials

2021 ◽  
Author(s):  
Dragana Radojčić ◽  
Jian Hong ◽  
Zoran S. Petrovic
Keyword(s):  
Epoxy Resins ◽  
Linseed Oil ◽  
Polymer Networks ◽  
Regular Structure ◽  
Glass Transitions ◽  
Cross Link ◽  
New Paradigm ◽  
Natural Oils ◽  
Link Density ◽  
Cross Link Density

Abstract The direct conversion of natural products to useful engineering materials is desirable from both economic and environmental considerations. We are describing the synthesis and properties of 100 % oil-based epoxy resins generated from three epoxidized oils. The catalyst, tris(pentafluorophenyl)borane (B(C6F5)3) in toluene, allowed for controlled cationic polymerization at a very low concentration. Epoxidized oils (derived from triolein, soybean, and linseed oil) had varying epoxy content, rendering resins of different cross-link density. The polymerization was carried out at room temperature followed by post-curing at elevated temperature to speed up conversion. Epoxy resins were amorphous transparent glasses with glass transitions below glass transitions and hard rubbers above. Despite their high cross-link density, these materials show relatively low Tg’s reflecting the aliphatic nature of fatty acids and the presence of plasticizing “dangling” chains. The structure of the triglyceride starting oils influenced the properties of the resulting materials: the more regular structure of triolein compared to the very heterogeneous structures of soybean and linseed oils seemed to have enhanced some properties of the polymer networks. These epoxy polymers are potentially useful as encapsulating and potting compounds for electronic applications.

scholarly journals Multivalency in healable supramolecular polymers: the effect of supramolecular cross-link density on the mechanical properties and healing of non-covalent polymer networks

2014 ◽  
Vol 5 (11) ◽  
pp. 3680-3688 ◽  
Author(s):  
Lewis R. Hart ◽  
James H. Hunter ◽  
Ngoc A. Nguyen ◽  
Josephine L. Harries ◽  
Barnaby W. Greenland ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polymer Blends ◽  
Crosslink Density ◽  
Polymer Networks ◽  
Supramolecular Polymers ◽  
Supramolecular Polymer ◽  
Cross Link ◽  
Link Density ◽  
Cross Link Density

Mechanical properties of healable supramolecular polymer blends correlate to non-covalent “crosslink density”.

Rheological investigation of swollen gluten polymer networks: effects of process parameters on cross-link density

2003 ◽  
Vol 200 (1) ◽  
pp. 137-146 ◽  
Author(s):  
Sandra Domenek ◽  
Marie-Hélène Morel ◽  
Andreas Redl ◽  
Steéphane Guilbert
Keyword(s):  
Process Parameters ◽  
Polymer Networks ◽  
Cross Link ◽  
Link Density ◽  
Cross Link Density ◽  
Gluten Polymer

Boron nitride for modification of rubber based on isoprene elastomer

2020 ◽  
pp. 105-112
Author(s):  
K. S. Zhansakova ◽  
E. N. Eremin ◽  
G. S. Russkikh ◽  
O. V. Kropotin
Keyword(s):  
Mechanical Properties ◽  
Boron Nitride ◽  
Gradual Increase ◽  
Physical And Mechanical Properties ◽  
Curing Time ◽  
Cross Link ◽  
Start Time ◽  
Link Density ◽  
Cross Link Density ◽  
Isoprene Rubber

The work studies vulcanization characteristics of elastomers based on isoprene rubber filled with carbon black N330 and boron nitride (BN). The influence of the boron nitride (BN) concentration on technological, dynamic, physical and mechanical properties of elastomers has been researched. The application of boron nitride for producing rubber with good properties has been considered. With a gradual increase of the inert filler BN concentration up to 35%, a decrease in the curing rate by 33% and polymer cross-link density by 26% is observed. Moreover, the start time of vulcanization increases by almost 300%, the optimal curing time by 200%.

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