A5046478950- Polymer crystallization and properties
- Polymer Nanocomposites and Properties
- Rheology and Fluid Dynamics Studies
- Advanced Sensor and Energy Harvesting Materials
- Dielectric materials and actuators
- Fuel Cells and Related Materials
- High voltage insulation and dielectric phenomena
- biodegradable polymer synthesis and properties
- Electrospun Nanofibers in Biomedical Applications
- Advanced Polymer Synthesis and Characterization
- Polymer composites and self-healing
- Fiber-reinforced polymer composites
Tianjin University
2019-2021
The phase transition from the kinetically favored tetragonal form II into thermodynamically stable hexagonal I is general phenomenon and core issue in application of polybutene-1-based materials. It known that variation molecular structure by copolymerizing counits imposition external stretching both greatly affect transition. In this work, a series butene-1/4-methyl-1-pentene (4M1P) random copolymers were synthesized with dimethylpyridylamidohafnium/organoboron catalyst, where 4M1P...
The incorporation of the secondary co-units may not only change kinetics and polymorphism crystallization but also affect melting behavior polymers, leading to memory effect even above equilibrium temperature. In this work, a series butene-1/norbornene random copolymers with 0–4.57 mol % steric norbornene (NBE) was synthesized using rac-ethyl(1-indenyl)2 zirconium dichloride as catalyst. melt crystallization, solid-phase transition, associated incomplete were studied differential scanning...
Flow-induced crystallization of poly(vinylidene fluoride) (PVDF) was investigated for a broad temperature range from 160 to 220 °C by in situ synchrotron wide-angle X-ray diffraction (WAXD) and small-angle scattering (SAXS). Unexpectedly, the electroactive β-phase is obtained directly melt with an extensional flow at 160–200 °C, which contrary quiescent generating pure α-phase. For observation equatorial SAXS streak without WAXD signals indicates generation fibrillar shish. Second, within...
The flow-induced crystallization of poly(vinylidene fluoride) (PVDF)–ion composites in the presence externally added ions was investigated by situ wide-angle X-ray diffraction (WAXD) and ex Fourier transform infrared (FTIR) spectroscopy. In this work, two types hexadecyl trimethyl ammonium bromide (CTAB) tetrabutylammonium hydrogen sulfate (TBAHS) with distinct electrostatic interactions were chosen at a weight concentration 0.5% to design different influences on crystallization. For...
The intrinsic coupling effect between the multiscale microstructure and macroscopic performance is a fundamental issue in polymer engineering physics. Combing tensile testing situ wide-angle X-ray diffraction, stretching-induced polymorphic transformation from tetragonal form II into hexagonal I butene-1/1,5-hexadiene random copolymers was studied this work. mechanical response crystallite evolution of designed with various co-unit concentrations were combined to reveal interplay stretching...
Polymorphism is determined by the intrinsic molecular architecture designed via chemical synthesis and external flow stimuli applied in practical processing. In this work, flow-induced crystallization of butene-1/1,5-hexadiene random copolymers with 1.38–2.81 mol % cyclic methylene-1,3-cyclopentane (MCP) co-units was studied combination situ synchrotron wide-angle X-ray diffraction (WAXD) an extensional rheometer. The results show that incorporation unique MCP facilitates appearance trigonal...