Study on Thickening PET with Hexamethylene Diisocyanate(HDI)
In this paper,polyethylene terephthalate(PET)was extruded by reactive extrusion using hexamethylene diisocyanate(HDI)as chain extender.The effects of HDI content on intrinsic viscosity,melt rheology,thermal properties,melt crystallization behavior,crystallization morphology,rheological behavior and mechanical properties of PET were studied.The results showed that after one-pass processing,the intrinsic viscosity of PET increased when the amount of chain extender was less.When the dosage of chain extender was more than 1%,the intrinsic viscosity of PET increased with the increase of HDI dosage.When it exceeded 1.6%,the intrinsic viscosity of PET decreased slightly,and the melt flow rate decreased gradually with the increase of chain extender dosage.When the amount of chain extender was high,the crystallization temperature and crystallinity of PET decreased slightly,and the melting peak shifted to the left.The addition of chain extender did not affect the single crystal structure of PET.With the increase of the amount of chain extender,the mechanical properties of PET were improved.