Preparation And Property Investigation Of Regularly Multidefined Functionalized Metathesis Polymers

Acyclic diene metathesis polymerization(ADMET) is a method of carbon-carbon bond formation and it belongs to the step polymerization mechanism. We named the polymer it produces metathesis polymer. This thesis is aimed at synthesizing a series of polymers via ADMET. Generally, there are several methods that could be used to prepare functional polymers, like polymerization of functional monomers or functionalization of polymers. As with this thesis, firstly we synthesize the functional monomers with functional groups by the synthetic organic reactions, then they polymerize to become the functional polymers, along whose chains the functional groups could be distributed regularly, thus this method could facilitate the investigation of structure-property relationship of polymers. On the other hand, in order to systematically making research on this series of polymers, we synthesize many kind of polymers with different type and distribution of functional groups. After successfully synthesized all the polymers, we determine the structure of polymers via FT-IR, 1H NMR and 13 C NMR. The molecular weight and molecular weight distribution of polymers are characterized by GPC and the thermal properties including the melting points, melting enthalpy, crystalline points and crystalline enthalpy are investigated via DSC. Heat resisting properties of polymers are investigated by TGA. We also make research on the crystalline properties of polymers via DSC and XRD. The results show that the structures of polymers are well-defined. The polymers containing the aryl ether units exhibit increased melting points and enhanced heat resisting properties, and also show a sequence of melting/crystallization phenomena. Presumably, this phenomena is due to the steric effect of aryl ether units which decrease the flexibility of polymers. However, this phenomena disappears when the distance of every aryl ether units along the chain of polymers is shorter, which probably is related with the decreased dominant effect of the ethylene segments.