The available on‐line and in‐line sensor technologies developed for polymerization reactors from 1990 until today are discussed and critically reviewed. About 600 references are included, which evidence the growth in sensor technology in the last two decades. Sensors for operational parameters in polymer reactors (i.e. temperature, pressure, level and flow) as well as sensors for polymer property monitoring (i.e. calorimetry, chromatography and spectroscopy, among others) are included. Complementary topics such as state estimation, multivariate statistical methods, fault diagnosis techniques and optimal sensor selection and location are briefly covered.
Photo‐ and thermal stabilities of poly(propylene) (PP)/SiO2 nanocomposites were studied by varying the particle size of the SiO2 nanoparticles. It was found that smaller SiO2 nanoparticles improved the stabilities of the nanocomposites by depressing the size of spherulites. The phenomenon was successfully explained within the infectious spreading model, where the spatial spreading of oxidation was delayed at the interfacial region between the spherulites.
