it has been discovered that acetylene - substituted schiff &# 39 ; s bases can be prepared from the reaction of acetylene - substituted amines and dicarboxaldehydes or from the reaction of acetylene - substituted aldehydes and diamines . the molecular structures of these products can be illustrated as follow : where r may be -- n ═ n -- ar &# 39 ;-- ch ═ n --, or -- ch ═ n -- ar &# 39 ;-- n ═ ch -- and ar is phenylene , biphenylene , naphthylene , anthracene , phenanthrene , pyrene , alkyl or aryl substituted phenylene , alkyl or aryl substituted biphenylene , alkyl or aryl substituted naphthylene , and heterocyclic analogues of the above wherein one or more of the aromatic carbon atoms is replaced by a nitrogen or sulphur atom . the advantages of this invention lie in the fact that acetylene - substituted schiff &# 39 ; s bases can be made very easily , they usually have low melting points prior to cure , they can polymerize through a tacky viscous state , and they can produce partially and fully conjugated polymeric products . acetylene - substituted amines suitable for use in preparing the prepolymers of this invention have the formula : where ar is as defined above . however ar may also be a compound whose general structure is : ## str1 ## aromatic dicarboxaldehydes suitable for use in preparing the prepolymers of this invention have the general formula where ar &# 39 ; may be phenylene , diphenylene , terphenylene , naphthalene , anthracene , phenanthrene , or a compound whose structure is φ -- x &# 39 ;-- φ wherein φ is phenylene and x &# 39 ; is o , s , ch 2 , -- ch 2 -- n , -- co --, -- cf 2 -- n , & gt ; c ( ch 3 ) 2 , or -- so 2 --. a typical reaction sequence leading to the production of one species of oligomers in accordance with this invention is as follows : ## str2 ## the preferred compounds of this invention are synthesized from ortho or para substituted amino - phenyl acetylenes which yield fully conjugated oligomers . the term &# 34 ; fully conjugated &# 34 ; is understood to imply that each double or triple bond is attached to a single bond which in turn is attached to another double or triple bond as shown below : ## str3 ## in a similar manner , conjugated schiff &# 39 ; s bases can be made by the reaction of a diamine with ethynylphenyl ketone or ethynylphenyl aldehyde . those reactions are illustrated by the following formulas : ## str4 ## where ar is as defined above . oligomers having structures such as that shown at ( 6 ) theoretically are superconductors in themselves . however , there is a significant energy barrier ( activation energy ) which prevents the transfer of electrons from one molecule to the next . nevertheless , these molecules can be polymerized into polymers which also have completely conjugated sequences through the acetylenic end groups . this factor is what makes the acetylene - substituted schiff &# 39 ; s bases so unique . there are several mechanisms for causing acetylene - substituted schiff &# 39 ; s bases to polymerize . for example , an oxidative coupling process would yield from ( 6 ) ## str5 ## where acetylene to acetylene sequences ( butadiyne groups ) (-- c . tbd . c -- c . tbd . c --) are produced in the chain and n may range from 2 to about 10 , 000 . on the other hand , a relatively low temperature thermal polymerization produces ## str6 ## which contains the ene - yne sequence ## str7 ## in the chain . aside from the conductivity aspects , occasioned by the degree of conjugation discussed above , acetylene - terminated schiff &# 39 ; s bases may be polymerized at temperatures as low as 150 °- 160 ° c ., depending upon the specific prepolymers , which constitutes a resin processing advantage . at 160 ° c . the terephthalaldehyde / m - aminophenylacetylene oligomer had such a long &# 34 ; pot life &# 34 ; that it did not reach a tacky state for 1 - 11 / 4 hours and at 170 ° c . it reached the tacky state in 1 / 2 hour . the capacity to exhibit long pot lives is also a great advantage in resin processing . a detailed method for synthesizing one of the compounds of this invention is shown in the following example . 3 - aminophenylacetylene ( m . w . 117 , 15 . 7 g , 0 . 13 moles ) and absolute ethanol ( 100 ml ) were placed into a 200 ml 3 - necked round bottomed flask equipped with a mechanical stirrer . terephthalaldehyde ( m . w . 134 , 9 . 0 g , 0 . 067 moles ) was added portion - wise over 30 minutes . additional absolute ethanol ( 70 ml ) was added to facilitate mixing ( product is insoluble in cold ethyl alcohol ). the reaction mixture was allowed to stir over the weekend , then the solution was filtered and the solid product washed with etoh . it was then re - dissolved in hot ethanol ( about 2 liters ) and allowed to cool . when cooled thoroughly ( refrigerated ) the crystalline product was collected by filtration and washed with cold ethanol . the yield was 19 . 9 g and the crystals were pale yellow . the product melted at 136 °- 139 ° c . infrared analysis and nuclear magnetic resonance spectroscopy substantiated the theoretical molecular structure . for example , nmr showed the acetylene : m - phenylene : p - phenylene : ═ ch hydrogen ratios to be 1 : 4 : 2 : 1 ( precisely what theory predicts ). the product has the structure : ## str8 ## this example serves to demonstrate that these acetylenic schiff &# 39 ; s bases are homopolymerizable . samples of the product of example 1 were heated at various temperatures above their melting points and the time required for them to polymerize to a tacky state , and then to the resin state are shown below . ______________________________________ tacky state resinous state______________________________________ @ 195 ° c . 2 - 3 min . 5 min . 188 ° c . 9 min . 180 ° c . 23 min . 30 min . 170 ° c . 30 min . 40 min . 160 ° c . 60 min . 80 min . 150 ° c . & gt ; 21 / 2 hours______________________________________ it is evident from these results that &# 34 ; pot life &# 34 ; can be extended to over 1 hour , simply by lowering the cure temperature . this is an excellent handling characteristic and makes the fabrication of composite structures easy to implement . having completely disclosed the nature of my invention and provided teachings to enable others to make and use the same , the scope of my claims may now be understood as follows :