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POLYCYANATE

The aeronautics sector is a significant composite consumer, particularly in terms of turnover, because of the high proportion of advanced composites used with matrices such as epoxies, polycyanates, polyimides, PEEK, and reinforcements such as carbon fibres. [Pg.41]

Crosslinked polytriazines (polycyanurates) with still higher crosslinking density are obtained from polycyanates based on novolak resins (Scheme 4)... [Pg.43]

Phosphorylated and thiophosphorylated aminoheterocycles 82UK239. Polycyanated heterocycles 80UK637. [Pg.278]

A variety of CEs with tailorable physico-chemical and thermo-mechanical properties have been synthesized by appropriate selection of the precursor phenol [39,40]. The physical characteristics like melting point and processing window, dielectric characteristics, environmental stability, and thermo-mechanical characteristics largely depend on the backbone structure. Several cyanate ester systems bearing elements such as P, S, F, Br, etc. have been reported [39-41,45-47]. Mainly three approaches can be seen. While dicyanate esters are based on simple diphenols, cyanate telechelics are derived from phenol telechelic polymers whose basic properties are dictated by the backbone structure. The terminal cyanate groups serve as crosslinking sites. The polycyanate esters are obtained by cyanation of polyhydric polymers which, in turn, are synthesized by suitable synthesis protocols. Thus, in addition to the bisphenol-based CEs, other types like cyanate esters of novolacs [37,48], polystyrene [49], resorcinol [36], tert-butyl, and cyano substituted phenols [50], poly cyanate esters with hydrophobic cycloaliphatic backbone [51], and allyl-functionalized cyanate esters [52] have been reported. [Pg.12]

Di- and polycyanates are starting materials for the preparation of polymers, with most of the polycyanates undergoing self-trimerization upon heating.261 263 The trimerization tendency depends on the chemical nature of the polycyanates, the applied temperature and the presence of water or catalysts. The exothermic formation of polytriazines may even occur at room temperature, but generally occurs at 80-150°C and sometimes at 200-250 °C. The polymeric material shows a high thermal stability and is used in various industrial applications (see Introduction). [Pg.687]

Cyanate esters are a family of aryl dicyanate monomers that contain the reactive cyanate (-0-C=N) fimctional group. When heated, this cyanate functionality undergoes an exothermic cyclotrimerization reaction to form triazine ring connecting units, resulting in the formation of a thermoset polycyanate polymer. [Pg.219]

Cyanate/Cyanurate. When aryl cyanate esters are heated to 150 to 250°C, they cyclotrimerize to cyanuric acid esters (Fig. 3.62). They can be catalyzed by organo-metallic and active hydrogen compounds. When the monomer is a dicyanate such as bisphenol A dicyanate (Fig. 3.63), the result is a highly cross-linked heterocyclic polymer (Table 3.57). Using a novolac polycyanate has produced Tg and useful life over 300°C. [Pg.182]

Nair and co-workers [203] reported polycyanate esters of an imide-modified novolac of different maleimide content. The resins underwent a two-stage independent thermal curing through trimerisation of the cyanate groups, as well as addition polymerisation of maleimide moieties. On heating, cyanate esters were transformed into an imido-phenolic-triazine network polymer. The cured resins exhibited a higher initial decomposition temperature compared with the cured maleimide novolacs. However, the thermal stability was found to be inferior to the conventional phenolic-triazine resin. [Pg.134]

This technique has found the following applications in addition to those discussed in Sections 10.1 (resin cure studies on phenol urethane compositions) [65], 12.2 (photopolymer studies [66-68]), and 13.3 (phase transitions in PE) [66], Chapter 15 (viscoelastic and rheological properties), and Section 16.4 (heat deflection temperatures) epoxy resin-amine system [67], cured acrylate-terminated unsaturated copolymers [68], PE and PP foam [69], ethylene-propylene-diene terpolymers [70], natural rubbers [71, 72], polyester-based clear coat resins [73], polyvinyl esters and unsaturated polyester resins [74], polyimide-clay nanocomposites [75], polyether sulfone-styrene-acrylonitrile, PS-polymethyl methacrylate (PMMA) blends and PS-polytetrafluoroethylene PMMA copolymers [76], cyanate ester resin-carbon fibre composites [77], polycyanate epoxy resins [78], and styrenic copolymers [79]. [Pg.579]

EM-3 120 C cure expanding epoxy film, with EM-3N being a natural colour formulation EM-5 230°C cure, expanding polycyanate film EM-6 95°C cure, expanding core splice epoxy film... [Pg.325]

RS-4 175°C cure, polycyanate film adhesive with two variants ... [Pg.325]

Our method for forming the polycyanate ester overlayer on disk surfaces is illustrated in Figure 5. This method consists of two steps ... [Pg.412]

Normalized infrared adsorbance at the wave number 1380 cm" for polycyan-urate films of different thickness for the unmodified and the NEAP-modified sample. [Pg.636]

Aromatic polycyan urates Laser pyrolysis - - Study of polymer linkages and networks [47]... [Pg.31]


See other pages where POLYCYANATE is mentioned: [Pg.12]    [Pg.18]    [Pg.19]    [Pg.893]    [Pg.23]    [Pg.140]    [Pg.89]    [Pg.178]    [Pg.98]    [Pg.184]    [Pg.121]    [Pg.43]    [Pg.43]    [Pg.325]    [Pg.329]    [Pg.129]    [Pg.411]    [Pg.412]    [Pg.412]    [Pg.414]    [Pg.417]    [Pg.249]   
See also in sourсe #XX -- [ Pg.11 ]




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Polycyanate ester

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