A Precision Ethylene-Styrene Copolymer with High Styrene Content from Ring-Opening Metathesis Polymerization of 4-Phenylcyclopentene

作者：Neary William J; Kennemur Justin G^*

来源：Macromolecular Rapid Communications, 2016, 37(12): 975-979.

DOI：10.1002/marc.201600121

• cyclopentenes
• polyolefins
• polypentenamers
• ring-opening metathesis polymerization (ROMP)
• thermodynamics

Ring-opening metathesis polymerization of 4-phenylcyclopentene is investigated for the first time under various conditions. Thermodynamic analysis reveals a polymerization enthalpy and entropy sufficient for high molar mass and conversions at lower temperatures. In one example, neat polymerization using Hoveyda-Grubbs second generation catalyst at -15 degrees C yields 81% conversion to poly(4-phenylcyclopentene) (P4PCP) with a number average molar mass of 151 kg mol(-1) and dispersity of 1.77. Quantitative homogeneous hydrogenation of P4PCP results in a precision ethylene-styrene copolymer (H-2-P4PCP) with a phenyl branch at every fifth carbon along the backbone. This equates to a perfectly alternating trimethylene-styrene sequence with 71.2% w/w styrene content that is inaccessible through molecular catalyst copolymerization strategies. Differential scanning calorimetry confirms P4PCP and H-2-P4PCP are amorphous materials with similar glass transition temperatures (T-g) of 17 +/- 2 degrees C. Both materials present well-defined styrenic analogs for application in specialty materials or composites where lower softening temperatures may be desired.

• 出版日期2016-6