The Preparation and Properties of A New Family of Amorphous Fluoropolymers: Teflon® Af

1989 ◽  
Vol 167 ◽  
Author(s):  
Paul R. Resnick
Keyword(s):  
Thin Films ◽  
Glass Transition ◽  
Thermal Properties ◽  
Physical Properties ◽  
Chemical Resistance ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
New Family ◽  
The Family ◽  
Solution Cast

AbstractTeflon® AF is a family of amorphous fluoropolymers with glass transition temperatures as high as 300° based on bis-2,2-trfluoromethyl-4,5-difluoro-1,3-dioxole, (I), which has unusual properties [1–3] (Figure 1). The family retains the superior electrical, chemical resistance and thermal properties associated with fluoropolymers. In addition the polymers have high optical clarity, limited solubility in some commercially available perfluorinated ethers such as Fluorinert® FC-75 and improved physical properties below their glass transition temperatures (Figure 2). Teflon® AF polymers may be either solution cast into clear micron thin films or melt processed into a variety of forms.

Glass transition temperatures in pure and composite organic thin-films

2018 ◽  
Vol 60 ◽  
pp. 45-50 ◽  
Author(s):  
Han-Nan Yang ◽  
Shou-Jie He ◽  
Tao Zhang ◽  
Jia-Xiu Man ◽  
Nan Jiang ◽  
...  
Keyword(s):  
Thin Films ◽  
Glass Transition ◽  
Organic Thin Films ◽  
Transition Temperatures ◽  
Glass Transition Temperatures

Multiple glass transition temperatures of polymer thin films as probed by multi-wavelength ellipsometry

2011 ◽  
Vol 519 (6) ◽  
pp. 2031-2036 ◽  
Author(s):  
Abderrahim El Ouakili ◽  
Guillaume Vignaud ◽  
Eric Balnois ◽  
Jean-François Bardeau ◽  
Yves Grohens
Keyword(s):  
Thin Films ◽  
Glass Transition ◽  
Polymer Thin Films ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Multi Wavelength

Synthesis of novel allylamine-fluorene based benzoxazine and its copolymerization with typical benzoxazine: curing behavior and thermal properties

2020 ◽  
Vol 44 (43) ◽  
pp. 18917-18928
Author(s):  
Ting Wang ◽  
Zhi-cheng Wang ◽  
Zhong-cheng Pan ◽  
Abdul Qadeer Dayo ◽  
Wen-bin Liu ◽  
...  
Keyword(s):  
Glass Transition ◽  
Thermal Properties ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Curing Behavior

Poly(t-BF-sa-a) showed much better thermal properties and glass transition temperatures than traditional fluorene-based benzoxazine monomers.

Influence of water absorption on mechanical properties and glass transition temperatures of polyamide6/hexagonal boron nitride composites

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kawaljit Singh Randhawa ◽  
Ashwin Patel
Keyword(s):  
Glass Transition ◽  
Thermal Properties ◽  
Hexagonal Boron Nitride ◽  
Water Molecules ◽  
Mechanical And Thermal Properties ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
Content Type ◽  
Environmental Humidity ◽  
Influence Of Water

PurposeThe absorption of moisture/water can affect the mechanical and thermal properties of polymers and polymer composites as many polymers, mainly polyamide thermoplastics, are sensitive to environmental humidity and can absorb a large amount of moisture. This paper investigates the effect of water molecules' absorption on mechanical and thermal properties of polyamide6/hexagonal boron nitride (PA6/h-BN) composites.Design/methodology/approachThe PA6/h-BN composites were exposed to an open environment and water for 15 days to analyse the effect of humidity/water molecules' absorption on mechanical and thermal properties. The tensile strength, hardness and impact strength of materials were measured and compared. The scanning electron microscopy (SEM), x-ray diffraction (XRD) and differential scanning calorimetry (DSC) analyses were utilized to see the influence of water absorption on microstructure, crystallinity and glass transition temperatures.FindingsAfter exposing materials to an open environment and water, the tensile strength and hardness were found to decline, while improvement in impact strength was noticed. SEM characterization revealed the formation of voids/pockets in water-immersed materials. DSC analysis revealed the loss in glass transition temperatures, and XRD analysis revealed the loss in crystallinity of water-immersed materials.Originality/valueEnvironmental conditions vary according to the geographical areas, and it varies in many countries throughout the year. Polyamides are sensitive to the environmental humidity and can absorb a large amount of moisture from the environment. It becomes necessary to test these materials in their original working conditions, and sometimes it is mandatory to see the effects of extreme environmental conditions on a component. In this article, efforts have been made to investigate the influence of extreme humidity/water conditions on thermo-mechanical properties of PA6/h-BN composites.

Synthesis and Thermal Properties of Azobenzene Core Polyester Dendrimers with Trityl Groups at the Periphery

2018 ◽  
Vol 762 ◽  
pp. 171-175 ◽  
Author(s):  
Lauma Laipniece ◽  
Valdis Kampars
Keyword(s):  
Glass Transition ◽  
Thermal Properties ◽  
Growth Strategy ◽  
Transition Temperatures ◽  
Glass Transition Temperatures ◽  
The Core ◽  
Azobenzene Chromophore

We have synthesized polyester type dendrimers containing azobenzene chromophore in the core and trityl groups at the periphery using divergent growth strategy up to 3rdgeneration. We analyzed dendrimer samples using NMR, HPLC, TG, DSC and UV-Vis techniques. We found out that functionalization of dendrimer periphery is not complete. Dendrimers with trityl groups at the periphery have glass transition temperatures in the range 73-87 °C.

scholarly journals High Glass Transition Temperature Fluoropolymers for Hydrophobic Surface Coatings via RAFT Copolymerization

2016 ◽  
Vol 69 (7) ◽  
pp. 725 ◽  
Author(s):  
Molly Rowe ◽  
Guo Hui Teo ◽  
James Horne ◽  
Omar Al-Khayat ◽  
Chiara Neto ◽  
...  
Keyword(s):  
Thin Films ◽  
Contact Angle ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Surface Coatings ◽  
Transition Temperatures ◽  
High Glass Transition Temperature ◽  
Glass Transition Temperatures ◽  
Hydrophobic Polymers

The preparation of polymer thin films or surface coatings that display a static water contact angle >95° often requires hierarchical roughness features or surface functionalization steps. In addition, inherently hydrophobic polymers such as fluoropolymers often possess low glass transition temperatures, reducing their application where thermal stability is required. Herein, the first reported synthesis of 2,3,4,5,6-pentafluorostyrene (PFS) and N-phenylmaleimide (NMI) via reversible addition–fragmentation chain-transfer (RAFT)-mediated free radical polymerization is presented, with a view towards the preparation of inherently hydrophobic polymers with a high glass transition temperature. A suite of copolymers were prepared and characterized, and owing to the inherent rigidity of the maleimide group in the polymer backbone and π–π interactions between adjacent PFS and NMI groups, very high glass transition temperatures were achieved (up to 180°C). The copolymerization of N-pentafluorophenylmaleimide was also performed, also resulting in extremely high glass transition temperature copolymers; however, these polymers did not exhibit characteristics of being under RAFT control. Thin films of PFS-NMI copolymers exhibited a static contact angle ~100°, essentially independent of the amount of NMI incorporated into the polymer.

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