Fabrication and characterization of polyurethane-coated fabrics for collapsible diesel tanks

2000 ◽  
Vol 214 (5) ◽  
pp. 487-491
Author(s):  
T. V. T. Velan ◽  
I. M. Bilal ◽  
S Arumugham
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
High Molecular Weight ◽  
Low Molecular Weight ◽  
Adverse Conditions ◽  
Physical Chemical ◽  
Fuel Tanks ◽  
Fabrication And Characterization ◽  
Coated Fabrics

Polyurethanes synthesized from diols of low, medium and high molecular weight ( Mw = 1000, 2000 and 3000 respectively) with low free isocyanates were used to fabricate coated fabrics. The physical, chemical and mechanical properties of these coated fabrics and polymer films were studied to establish their suitability for fabricating collapsible fuel tanks to store diesel for long periods under adverse conditions. Fabrics coated with low molecular weight polyurethanes are found to be more suitable for storing diesel fuel compared with those coated with medium and high molecular weight polyurethanes.

Chemistry and Characterization Of Polyimides Derived from Poly(Amic Alkyl Esters)

1991 ◽  
Vol 227 ◽  
Author(s):  
Willi Volksen ◽  
D. Y. Yoon ◽  
J. L. Hedrick ◽  
D. Hofer
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Temperature Regime ◽  
Amic Acid ◽  
Chain Extension ◽  
Low Molecular Weight ◽  
Alkyl Esters ◽  
Work Up ◽  
Polyimide Precursor

ABSTRACTThe modification of the pendant acid groups along the poly(amic acid) backbone in the form of alkyl ester groups leads to greatly improved polyimide precursors. These poly(amic alkyl esters) are characterized by the absence of hydrolytic instability due to elimimation of the “monomer-polymer” equilibrium associated with poly(amic acids), a broad imidization temperature regime, improved solubility characteristics, and enhanced mechanical properties. In the absence of hydrolytic instability, it is now possible to use an aqueous work-up of the polyimide precursor. This presents an attractive synthetic pathway for the preparation of well-defined, amine-terminated oligomers. Such oligomers can then be utilized both in the preparation of low molecular weight, chain-extendable polyimide precursors as well as polyimide block copolymers. The higher imidization temperatures offered by the “amic ester” chemistry allows for more efficient chain extension prior to imidization. Alternatively, the lack of the “monomer-polymer” equilibrium and accompanying propensity for monomer randomization reactions presents a potential pathway for the preparation of polyimide blends.

Fabrication and characterization of supramolecular Cu-based metallogel thin-film based Schottky diode

2021 ◽  
Author(s):  
Vivek Kumar ◽  
Rishibrind Kumar Upadhyay ◽  
Daraksha Bano ◽  
Subhash Chandra ◽  
Deepak Kumar ◽  
...  
Keyword(s):  
Thin Film ◽  
Molecular Weight ◽  
Succinic Acid ◽  
Schottky Diode ◽  
Low Molecular Weight ◽  
Acetate Monohydrate ◽  
Fabrication And Characterization

In the present study, a stable supramolecular Cu (II)-metallogel has been synthesized via Copper (II) acetate monohydrate and succinic acid, engineered as a low molecular weight organic gelator. The mechanical...

Polyamide 6 and high molecular weight phenol novolac blend having excellent mechanical properties in humid conditions

2018 ◽  
Vol 32 (6) ◽  
pp. 778-794 ◽  
Author(s):  
Takayuki Hirai ◽  
Kenzo Fukumori ◽  
Taiji Ikawa ◽  
Tetsuya Oda
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Glass Transition ◽  
High Molecular Weight ◽  
Room Temperature ◽  
Glassy State ◽  
Physical And Mechanical Properties ◽  
Polyamide 6 ◽  
Low Molecular Weight ◽  
Melt Mixing

Polymer blends of polyamide 6 (PA6) and phenol novolac (PN) were prepared by melt mixing. Up to 30 wt% of high molecular weight PN (HPN) or low molecular weight PN (LPN) was blended with PA6, and the physical and mechanical properties were examined. The water absorption of PA6 is inhibited by PN, and this effect is independent of the molecular weight of PN. PA6 and PN are miscible, and their blends show a single glass transition temperature ( T g) that is higher than that of PA6. HPN can enhance the T g of PA6 more efficiently than LPN because of its high T g. PA6 and the PA6/LPN blend after immersion in water had lower-than-room-temperature T gs transitioning to rubbery states. In contrast, the PA6/HPN blend after immersion in water had a higher-than-room-temperature T g. The PA6/HPN blend in water has excellent mechanical properties in its glassy state compared to those of PA6 in the dry state. Thus, the PA6/HPN blend can be used to broaden the applications of PA6, especially in humid conditions.

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