Manipulating the Properties of Poly(1,4-Cyclohexylenedimethylene Terephthalate) (PCT) Just by Tuning Steric Configuration of 1.4-Cyclohexanedimethanol (CHDM)

The properties of poly(1,4-cyclohexylenedimethylene terephthalate) (PCT) are manipulated only by tuning the steric configuration of 1,4-cyclohexanedimethanol (CHDM). The chemical structures and compositions of PCTs are confirmed by nuclear magnetic resonance (H-1 NMR and C-13 NMR) before their thermal and mechanical properties are investigated by differential scanning calorimeter, thermogravimetric analyzer, and dynamic mechanical analysis. Results show that the ratio of cis- to trans-CHDM in PCTs has significant influences on their properties. The melting temperature of PCTs is varied from 251 to 313 degrees C, and the glass transition temperature is increased from 73 to 92 degrees C when the content of trans-CHDM in PCTs is increased from 10% to 96%. In addition, the crystallizability of PCT is also increased with the content of trans-CHDM. However, its thermal stability is decreased seriously when the melting temperature of PCT is higher than 280 degrees C. It is concluded that when the content of trans-CHDM is lower than 50% (PCT-10, PCT-28, and PCT-46), the balance of melting temperature, glass transition temperature, and thermal stability for PCT can be achieved. Just by varying the cis/trans ratio of CHDM, rather than the addition of other components, the properties of PCT can be manipulated.