Cooling‐rate effects play an important role in polymer processing because the materials experience rapid cooling when transferring from melt states to solid states. The traditional Tait equation has been used widely in representing the volumetric behaviors of polymers as a function of temperature and pressure, but not of cooling rate. Based on the dependence of glass‐transition temperature on cooling rate (i.e., θ = dTg/d log ∣ q ∣), the volumetric dependence on cooling rate is employed in this work to modify the traditional Tait P–V–T equation to become a time‐dependent P–V–T model. The physical meanings of the traditional Tait equation parameters are interpreted and, thereby, parameters in the new model are derived according to the material constant θ. The controlled cooling‐rate measurements of polymeric volumetric data have been performed in this work to verify the validity of the proposed model. Additionally, the material parameter θ, calculated from the measured data of polystyrene (PS) (Chi‐Mei PG‐33) in this work, equals 2.85 K, which is close to 2.86 K calculated from the Greiner‐Schwarzl work. Furthermore, a comparison of the predicted results with the experimental data both in this work and from literature is discussed under different pressures and various cooling rates. The results have indicated that the proposed non‐equilibrium P–V–T model closely correlates with experimental data.

β-Myrcene, a bio-based monoterpene derived from plants, was introduced to replace butadiene in the solution-polymerized styrene-butadiene rubber by using the conventional anionic copolymerization technique. The anionic copolymerization of β-myrcene was found to be stoichiometric and controllable. A series of solution-polymerized styrene-myrcene-butadiene rubber (S-SMBR) with 100% conversion, high-molecular weight (150 000-200 000 Da), low polydispersity, and uniform compositions was obtained. The glass transition temperature of S-SMBR exhibited imperceptible variation with different myrcene/butadiene ratios. Interestingly, the introduction of such a long nonpolar pendant group containing isopropylidene could greatly improve carbon black dispersibility in the rubber. Furthermore, the wet skid resistance of the rubber could be improved without impairing its low rolling resistance. The tensile strength of S-SMBR was found to be higher than that prepared by radical emulsion copolymerization. The S-SMBR prepared by anionic solution copolymerization is thus a promising material for tires to attain sustainable development. HIGHLIGHTS• A bio-based monomer was successfully introduced to replace diene part in SBR through anionic polymerization.• Carbon black dispersibility in the rubber was greatly improved.• The wet skid resistance of the rubber could be improved without impairing its low rolling resistance.• Robust tensile behaviors were obtained compared with the rubber prepared by radical emulsion polymerization.

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Numerous studies have shown that ceramic materials with high dielectric constants and low dielectric losses can be obtained using donor–acceptor-doped TiO2. In this study, (La + Nb)-co-doped TiO2 [(La0.5Nb0.5) x Ti1−x O2 x-LNTO] ceramic powders were prepared using the sol–gel method. XRD demonstrates that LNTO is a rutile phase, and the lattice parameters change after doping, while X-ray photoelectron spectroscopy explains the doping mechanism, with doping of TiO2 producing oxygen vacancies and Ti3+, which form defective dipoles with the dopant ions to increase the dielectric constant of the material. The dielectric properties were investigated by physically co-blending x-LNTO/polyvinylidene difluoride (PVDF) composites. Compared with the TiO2/PVDF composite, the dielectric properties of the x-LNTO/PVDF composite were more excellent. The dielectric constant of 5-LNTO/PVDF reached 36.96, which was higher than that of the TiO2/PVDF composite (19.49) at a filler addition of 60 wt% and a frequency of 1 kHz.