Study Of Polymer Reactive Blending Process

It is an economical mean to manufacture polymer materials with desired properties through blending immiscible polymers. The performance of polymer blend has a deep affinity with the micro-structure and the components' properties; the morphology also has a relation with the components' relative content and the flow field while being processed. So it is of great importance to analysis the effect that how morphology and flow field can influence the blend's rheological behavior.The mathematical model existent can perfectly correlate rheological behavior and microscopic structures of polymers blend which has a "sea-island" structure, while for a "co-continuous" structure, the existing models, such as Veenstra model, although in some cases can have a good fit with the experimental data, because it does not take into account the interfacial tension between the incompatible polymer, the fitted result obtained by this model usually underestimates the dynamic modulus of the blend. In this work, a rheological model is suggested to correlate the linear viscoelasticity and the structural information of "co-continuous" blends. The dynamic modulus of co-continuous blends is composed of the contribution from components and the interface. The interfacial contribution, which is most important in the rheology of blends, is calculated from a simplified "co-continuous" structure. This model has been compared with some experimental results, which proves a reasonable connection between the "co-continuous" structure and linear viscoelasticity of blends.By using the typical thermodynamic incompatible blending system POE/PS, the influence of different morphology ("sea-island" structure and "co-continuous" structure) on the polymer reactive blending processes was investigated by means of rheology and morphology analysis. It is found that phase morphology has a significant influence on the polymer reactive blending processes. Interfacial reactions happen more easily in blend with "co-continuous" morphology due to its weak stability, while in the blends with the "sea-island" morphology; the interface reaction process depends on the ease of interface deformation, which blends with small viscosity ratio favors interfacial reactions.The effect of different flow field intensity and blending time on the polymer reactive blending processes was also investigated. For the system in this article, the flow field has no obvious effect on the final reactive product, but has a significant effect on the reactive process. The larger flow field can accelerate the reactive rate, and make the reaction fast to reach equilibrium.