Cyclic olefin copolymers containing both linear polyethylene and poly(ethylene-co-norbornene) segments prepared from chain shuttling copolymerization of ethylene and norbornene

The semicrystalline polyethylene (PE) and amorphous poly(ethylene-co-norbornene) copolymer have been used in a wide variety of applications, especially in packaging. It is a big challenge to improve the transparency of...

Robust Polymer Planar Bragg Grating Sensors Embedded in Commercial-Grade Composites

This contribution demonstrates the functionality of polymer planar Bragg grating (PPBG) sensors integrated into commercial-grade carbon fiber reinforced polymer (CFRP) components. Multiple CFRP specimens are generated by curing a stack of pre-impregnated fibers inside of a heated mechanical press, exposing the polymer sensor to a pressure of 7 bar and a temperature of 120 °C for 2 h. After integration, the sensor still exhibits a strong and evaluable signal. Subsequent flexural experiments reveal a linear response of the integrated sensor’s Bragg wavelength to the CFRP specimen’s maximum deflection. Additional findings demonstrate that the embedded PPBG can be used to detect plastic deformations of a CFRP workpiece, whereas a linear correlation of plastic deformation to the resulting Bragg signal offset is determined. A plausibility check of the obtained results is delivered by a comparison of three-point flexural experiments on bulk CFRP workpieces, without integrated sensors and additional specimens featuring external optical sensors affixed to their surface. It is found that PPBGs based on cyclic olefin copolymers are able to overcome the temperature-related limitations of traditional polymer-based optical sensors and can thus be directly integrated into commercial-grade composites during production.

The synthesis of cyclic olefin copolymers (COCs) by ethylene copolymerisations with cyclooctene, cycloheptene, and with tricyclo[6.2.1.0(2,7)]undeca-4-ene: the effects of cyclic monomer structures on thermal properties

The synthesis of amorphous ethylene copolymers with cycloheptene, cis-cyclooctene, or tricyclo[6.2.1.0(2,7)]undeca-4-ene using half-titanocene catalysts and the effects of ring size and structure on the thermal properties have been demonstrated.