TY - JOUR
T1 - Controlling thermomechanical behavior of semicrystalline hydrogenated polynorbornene through the cis- to trans-cyclopentylene ratio
AU - Klein, Jared P.
AU - Gdowski, Zachary M.
AU - Register, Richard A.
N1 - Funding Information:
This work was generously supported by the National Science Foundation, both by the Materials Research Science and Engineering Centers Program through the Princeton Center for Complex Materials (DMR‐1420541 and DMR‐2011750) and by the Polymers Program (DMR‐1402180 and DMR‐2002991). The authors would also like to thank Dr. Stephen Hahn (Dow Chemical) for providing the Pt‐Re/SiO catalyst. 2
Funding Information:
National Science Foundation, Materials Research Science and Engineering Centers Program, Grant/Award Numbers: DMR‐1420541, DMR‐2011750; National Science Foundation, Polymers Program, Grant/Award Number: DMR‐1402180 DMR‐2002991 Funding information
Publisher Copyright:
© 2021 Wiley Periodicals LLC.
PY - 2022/1/15
Y1 - 2022/1/15
N2 - Though polynorbornene synthesized by ring-opening metathesis polymerization has an intrinsically all-cis configuration of the cyclopentylene backbone rings, a fraction of these rings can be epimerized to the trans configuration during hydrogenation over suitable catalysts. By varying the method of hydrogenation, semicrystalline hydrogenated polynorbornenes (hPNs) with trans levels between 0 and 36% were obtained. With increasing trans content, the glass transition temperature, melting point, and enthalpy of melting decrease modestly. By contrast, the temperature at which the hPN crystal transitions into a rotationally disordered polymorph varies strongly with trans content, ranging from 126 °C (all-cis) to 71 °C at 27% trans; at trans contents of 34% and above, no rotationally-ordered phase is observed at any temperature. The room-temperature Young's modulus shows no dependence on trans content, while the yield stress drops by 20% at 1% trans content and slowly decreases further with additional epimerization. The temperature dependence of the Young's modulus differs for trans-containing versus all-cis polymers, while the temperature dependence of the yield stress is set by the polymorph type (rotationally ordered vs. disordered).
AB - Though polynorbornene synthesized by ring-opening metathesis polymerization has an intrinsically all-cis configuration of the cyclopentylene backbone rings, a fraction of these rings can be epimerized to the trans configuration during hydrogenation over suitable catalysts. By varying the method of hydrogenation, semicrystalline hydrogenated polynorbornenes (hPNs) with trans levels between 0 and 36% were obtained. With increasing trans content, the glass transition temperature, melting point, and enthalpy of melting decrease modestly. By contrast, the temperature at which the hPN crystal transitions into a rotationally disordered polymorph varies strongly with trans content, ranging from 126 °C (all-cis) to 71 °C at 27% trans; at trans contents of 34% and above, no rotationally-ordered phase is observed at any temperature. The room-temperature Young's modulus shows no dependence on trans content, while the yield stress drops by 20% at 1% trans content and slowly decreases further with additional epimerization. The temperature dependence of the Young's modulus differs for trans-containing versus all-cis polymers, while the temperature dependence of the yield stress is set by the polymorph type (rotationally ordered vs. disordered).
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U2 - 10.1002/pol.20210752
DO - 10.1002/pol.20210752
M3 - Article
AN - SCOPUS:85119453367
SN - 2642-4150
VL - 60
SP - 266
EP - 275
JO - Journal of Polymer Science
JF - Journal of Polymer Science
IS - 2
ER -