The Study On The Chain Extension Of PET During Reactive Extrusion And The Synthesis Of Chain Extender

2, 2' -Bis(2-oxazoline)(BOZ) is synthesized from the readily available starting agents — ethanol, oxalic acid dehydrate and ethanolamine according to the literature in this paper. The factors that affect the yield of diester, diethanol oxamide and dichlorodiethyl oxamide are studied. We improved the synthesis of diester, diethanol oxamide and dichlorodiethyl oxamide because of the problems coming forth during the experiments. The improved experiment omits the distillation of diester and the crystalline of diethanol oxamide and dichlorodiethyl oxamide. The results show the cost of synthesizing BOZ decreased and the yield of BOZ decreased slightly according to the literature. Diethanol oxamide and dichlorodiethyl oxamide are characterized by Infrared spectra (IR) and Differential scanning calorimetry (DSC). BOZ is characterized by IR, DSC and H-NMR.The chain extension of Poly(ethylene terephthalate) (PET) extended by BOZ and biscycloanhydride is studied with reactive extruder. The study can be summarized as following : the cooling system is improved; the effects of BOZ content, the temperature of reactive and screw rotation on the chain extension of PET are studied during reactive extrusion; viscosity molecular weight (Mη) and carboxyl content(CV) are measured; The effect of the dry time of virgin PET on the chain extension of PET is also studied. The results show Mη of PET increase from 22600g/mol to 27900 g/mol when the BOZ content is 0.6%, temperature is 250℃, screw rotation speed is 50rpm; When bis-cycloanhydride content is 0.8%, temperature 280℃, screw rotation speed 35 rpm, the Mη of PET can increase from 22200g/mol to 34160 g/mol.The thermal and crystallizing behavior is performed with DSC . The results show that the Tc of the chain extended PET increases and the Tm decreases. The Tc disappears after the samples are handled under constant temperature 135℃ for 12h. The crystalline degree and structure are studied by WAXD.The PP-g-MAH product was analyzed by IR ,WAXD. The rheology character of product is measured.