Phenylquinoxalines acetylene terminated

A thin molding of an acetylene-terminated phenylquinoxaline, fabricated by compression molding at 316°C for 26 hr and at 371°C for 5 hr, gave tensile strength of 103 MPa (15,000 psi), tensile modulus of 2.62 GPa (380,000 psi) and elongation of 5% (46). Preliminary unidirectional graphite fiber laminate properties are reported in Table VI. 

Table VI - Unidirectional HT-S Graphite Fiber Laminate Properties of Acetylene-Terminated Phenylquinoxaline Resin1 2...

A series of heterogeneous mixtures was made by adding various amounts of bis(triphenyl phosphine) nickel II chloride, as an initiator, to an acetylene-terminated phenylquinoxaline. The series was then evaluated using the Differential Scanning Calorimeter (DSC) and the shifts in the exothermic reaction with temperature were associated with the initiator concentrations. 

A substantial effort in this laboratory has been directed toward the synthesis and characterization of acetylene terminated oligomers for use as addition-curable, moisture-resistant, thermoset systems. Early work on the acetylene-terminated phenylquinoxalines demonstrated the moisture insensitivity of the product generated from the thermal cure. Studies of various difunctional acetylene-terminated monomers has demonstrated that the polymerization is a free radical propogation of the acetylene moiety to a linear conjugated polyene. 

The acetylene terminated quinoxaline oligomers, referred to as ATQ s, are prepared j5 from the reaction of benzil end-capped phenylquinoxaline oligomers and 3(3,4-diaminophenoxy)-phenylacetylene. The benzil end-capped oligomers are pre-... 

Norbomene-terminated imide NR-150B type polyimide Acetylene-terminated phenylquinoxaline Polyphenylquinoxalines with pendent phenylethynyl groups Semi-interpenetrating polyimide networks... 

The initial synthesis of acetylenic terminated phenylquinoxaline oligomers was reported in 1975. An alternate synthesis reported in 1976 involved endcapping o-diamino-termi-nated phenylquinoxaline oligomers with 4-(4-ethynylphenoxy)benzil to yield acetylene-terminated phenylquinoxaline oligomers (ATPQs) as shown in the representative scheme in Eq. (4) ... 

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