Synthesis and property research of birefringent polymers with predicted optical-mechanical parameters

Three series of new, optically sensitive polymers have been synthesized by copolymerization of bis-cyclopentadienyl oligomers and diallyl bis-dienophiles, on the basis of branched oligo ester acids, and on the basis of interpenetrating networks of the epoxy anhydride polymer and polybis-(allyl carbonate) - polypropylene glycol. A possibility of using the obtained and studied polymer materials in static and dynamic modeling of composite structures by the photoelasticity method has been demonstrated. The basic features of the modern level of the optical polarization method of research into structural and constructional stresses (the photoelasticity method) largely depends on the availability of modeling polymer materials having the required sets of optical-mechanical controlled parameters. Different lines of the photoelastic research impose specific requirements on the properties of optically sensitive polymers. For instance, freezing studies of the strain-stress state of composite structures require a set of model materials featuring the broadly varying high-elasticity modulus E_(infinity ) predetermined glass transition temperature (T_g), its values being equal for different materials. The least tedious and therefore basic technique of adjusting E_(infinity ) of optically sensitive polymers is their modification by plasticization or by linking rate adjustment. However, such E_(infinity ) reduction is accompanied by T_g and the freezing point (T_f). Moreover, plasticization produces polymers whose properties are time- dependent. It is more expedient to directly synthesize new cross-linked polymers whose optical-mechanical parameters will be determined by their chemical structure. The available data concerning the effect of the chemical structure of polymers on their thermal deformation properties allow such a preliminary prediction. The present paper presents findings of a research into properties of polymers synthesized by polydiene addition during the interaction of bis-cyclopentadienuyl oligomers with allyl esters of aliphatic and aromatic adics, triggered by stepwise heating of their mixture in the block at 100 to 200 degree(s)C. Linkin sites of the cross-linked polymers so formed are tetracarbocyclic nuclei of the norbornene type.