Monitoring of photopolymerization kinetics and network formation by combined real-time near-infrared spectroscopy and ultrasonic reflectometry

Influence of annealing conditions on elastic and dielectric properties of P(VDF‐TrFE) copolymer and its composites

“…The temperature and frequency dependences of tgδ in the neat P(VDF‐TrFE) were analyzed employing Cole‐Cole formalism (CC) (Eqs. and ): …”

Investigation of the Kinetics of Curing Reaction for the Resin Matrix Polymer Composite Based on Near-Infrared Spectroscopy

“…NIR spectra permitted to achieve an efficient distinction of different classes of natural resins and characterize natural polymers and resins in easel paintings, demonstrating that, even working at a microscopic level, the NIR region may support the identification of different materials [54,55].The NIR-ultrasonic setup has been employed to investigate photo polymerization of different resins, for instance, acrylates, epoxy acrylates and acrylated polyurethanes, so as to achieve a profound knowledge of the interdependent relationship between reaction kinetics and changes of mechanical/rheological properties [56]. …”

Processing

“…NIR spectroscopy has been used in combination with rheometry, DSC, atom force microscopy, and nanoindentation to study the dynamics of network formation and the evolution of morphology on nanoscale in an epoxy-amine thermosetting polymer [24]. The combined use of NIR and ultrasonic measurements for resin curing was studied by Alig and co-workers [25]. There is potential of online monitoring of the complete manufacturing process of aminoplast-impregnated paper sheets as prepregs for decorative laminates [26].…”

“…Only recently an interesting report has been published [25] that describes the combined use of an ultrasonic sensor with online NIR spectroscopy to follow the photo-polymerization kinetics of different resins (acrylates, epoxies, acrylated polyurethanes, cationic epoxies). Through simultaneous recording of the conversion-time (by NIR) and modulus-time (by ultrasound) profiles, the authors could differentiate between the mass and the diffusion controlled polymerization regimes [25]. Such a combination of various techniques is very useful since both the evolution of chemical composition/constitution of a hardening resin and the corresponding mechanical/ rheological properties are followed and analyzed together at the same sample.…”