Fluoromethylene Cyanate Ester Resins. Synthesis, Characterization, and Fluoromethylene Chain Length Effects

Autor:	Leonard J. Buckley, Arthur W. Snow
Rok vydání:	1997
Předmět:	Absorption of water Polymers and Plastics Organic Chemistry Infrared spectroscopy Cyanate Inorganic Chemistry chemistry.chemical_compound Monomer chemistry Cyanate ester Polymer chemistry Materials Chemistry Melting point Gravimetric analysis Thermal stability
Zdroj:	Macromolecules. 30:394-405
ISSN:	1520-5835 0024-9297
DOI:	10.1021/ma961182d
Popis:	Fluoromethylene cyanate ester resins derived from the monomer series N⋮CO−CH2(CF2)nCH2−OC⋮N (where n = 3, 4, 6, 8, and 10) have been synthesized and characterized. Monomer melting points range from −8 to 181 °C, and characterization includes 1H, 13C, and 19F NMR and IR spectroscopy and DSC. Purification is a critical requirement for melt processing. The thermal curing reaction is a cyclotrimerization reaction of the cyanate functional group to the cyanurate heterocycle. Physical properties of resin castings and their variation with an increase in fluoromethylene sequence length from 3 to 10 CF2 units include density, 1.77−1.91 g/cm3; critical surface tension, 40−23 dyn/cm; refractive index, 1.447−1.382; dielectric constant, 2.7−2.3; 100 °C immersion water absorption, 1.67−0.68%; Tg, 84−101 °C; glass/rubber thermal expansion coefficient, (109/238−152/275 ppm/ °C; and gravimetric thermal stability, 0.0196−0.0064% weight loss/min at 300 °C). Compared with aromatic cyanate ester resins, the fluoromethylene cy...
Databáze:	OpenAIRE
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