Preparation and Rheological Characterization of Long Chain Branching Polyglycolide

The long chain branching (LCB) polyglycolide (PGA) was successfully prepared by the successive reactions of the terminal hydroxyl groups of PGA with triglycidyl isocyanurate (TGIC) and pyromellitic dianhydride (PMDA). The influence of LCB produced by functional group reaction on rheological and crystallization behavior was studied and discussed through linear rheology, uniaxial elongation and DSC (differential scanning calorimetry). The much higher viscosity and the more notable strain hardening behavior of modified PGA indicates the LCB with high degree of entanglements are created. The melt strength of PGA is finally improved greatly and can make sure that the supercritical CO₂ foaming can be carried out successfully.