Abstract
Aliphatic poly(carbonate) glycols (PC-glycols) with different methylene unit lengths were synthesized from ethylene carbonate and 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol or 1,10-decanediol. The samples were coded 3002, 4002, 5002, 6002, 7002, 8002, 9002 and 10002 respectively, for each of these PC-glycols. Wide-angle X-ray diffraction (WAXD) and Differential Scanning Calorimetry (DSC) measurements were carried out to examine the structure of PC-glycols. A WAXD profile of 3002 showed only an amorphous halo with no particular crystalline peaks. Also, a DSC thermogram of 3002 showed the glass transition point but no melting peaks were observed. In the case of 5002, relatively weak WAXD peaks were observed, but no melting peaks were observed in the DSC thermogram. On the other hand, the other PC-glycols exhibited crystalline peaks in WAXD profiles and a melting peak in DSC thermograms. These results indicated that PC-glycols with odd numbered methylene unit length were more amorphous than those with even numbered methylene unit length.
Structural Model of PC-glycol 6002 determined with WAXD data simulation.
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