초록 |
Polymers prepared by the polymerization of olefins and carbon monoxide in a perfectly 1:1 alternating sequence are called aliphatic polyketone. The copolymer of ethylene and carbon monoxide (ECO) shows a high melting temperature (Tm), which is hard to be melt-processed. The decrease of Tm is desirable for ECO to be melt-processed. Aliphatic polyketone (EPCO) which has proper Tm for melt processing can be prepared by the incorporation of a third monomer, propylene, to ECO during polymerization, which has random repeat units of -(CH2-CH2-C=O)- and -(CH2-CH(CH3)-C=O)-. When EPCO is melted and shears during manufacture process, however, it shows poor processability due to the unexpected chemical reactions. We investigate changes in chemical structure during melt process. The time sweep experiments were conducted at various temperatures and shear rates to obtain a processing window. The resultant samples are analyzed chemically and morphologically. |