The morphous silicon films prepared by PECVD at substrate temperatures of 30℃ have been crystallized by rapid thermal annealing method, the budget of time-temperature in the annealing process is 600℃ for 120s, 850℃...The morphous silicon films prepared by PECVD at substrate temperatures of 30℃ have been crystallized by rapid thermal annealing method, the budget of time-temperature in the annealing process is 600℃ for 120s, 850℃ for 120s, and 950℃ for 120s. The results indicate the crystallization at 850℃ and 950℃ are better as shown in micro-Raman scattering and scanning electronic microscope.展开更多
This paper presents a method to measure the spontaneous extension of oriented PET fibredirectly during crystallization by twice annealing (constant-length and free-length). Samples be-fore and after the treatment were...This paper presents a method to measure the spontaneous extension of oriented PET fibredirectly during crystallization by twice annealing (constant-length and free-length). Samples be-fore and after the treatment were collected and examined by X-ray diffraction, DSC andbirefringence. The crystallinity, crystallite size, and orientation of both crystalline and amorphousparts between these samples are changed greatly which show that the extension is a consequence ofcrystallization and reorientation of uncrystallized segments along the fibre direction. The results ofthis study are not only important to understand the mechanism of supermolecular structurechanges during crystallization, but also useful to the industrial technology of crystallization spin-ning.展开更多
The effects of the annealing process on the mechanical properties and crystallization behaviors of polypropylene random copolymer（PP-R） composites were investigated using differential scanning calorimetry（DSC）, wi...The effects of the annealing process on the mechanical properties and crystallization behaviors of polypropylene random copolymer（PP-R） composites were investigated using differential scanning calorimetry（DSC）, wide-angle X-ray diffraction（WAXD）, and dynamic mechanical analysis（DMA）, and scanning electron microscopy（SEM）. The experimental results indicated that the annealing process significantly influenced the comprehensive properties of PP-R composites. At temperatures below 23 ℃, the impact strength of the PP-R composites annealed at 120 ℃ for 6 h was relatively high at 74.73 k J/m^2, which was 16.8% higher than that of the samples annealed at 80 ℃ for 6 h. At low temperatures（-30-0 ℃）, the impact strength ranged from approximately 13.31 k J/m^2 to 54.4 k J/m^2. In addition, the annealing process conducted at 120 ℃ for 6 h improved the crystalline structure and low-temperature toughness of the PP-R composites and induced α-form to β-form crystal transformation. The work provides a possible method to reinforce and toughen the semicrystalline polymer at low temperatures（-30-0 ℃） by annealing.展开更多
文摘The morphous silicon films prepared by PECVD at substrate temperatures of 30℃ have been crystallized by rapid thermal annealing method, the budget of time-temperature in the annealing process is 600℃ for 120s, 850℃ for 120s, and 950℃ for 120s. The results indicate the crystallization at 850℃ and 950℃ are better as shown in micro-Raman scattering and scanning electronic microscope.
文摘This paper presents a method to measure the spontaneous extension of oriented PET fibredirectly during crystallization by twice annealing (constant-length and free-length). Samples be-fore and after the treatment were collected and examined by X-ray diffraction, DSC andbirefringence. The crystallinity, crystallite size, and orientation of both crystalline and amorphousparts between these samples are changed greatly which show that the extension is a consequence ofcrystallization and reorientation of uncrystallized segments along the fibre direction. The results ofthis study are not only important to understand the mechanism of supermolecular structurechanges during crystallization, but also useful to the industrial technology of crystallization spin-ning.
基金the Science and Technology Cooperation Program of Guizhou Province of China([2016]5673)the Excellent Youth and Science&Technology Talent Foundation of Guizhou Province of China([2015]29)
文摘The effects of the annealing process on the mechanical properties and crystallization behaviors of polypropylene random copolymer（PP-R） composites were investigated using differential scanning calorimetry（DSC）, wide-angle X-ray diffraction（WAXD）, and dynamic mechanical analysis（DMA）, and scanning electron microscopy（SEM）. The experimental results indicated that the annealing process significantly influenced the comprehensive properties of PP-R composites. At temperatures below 23 ℃, the impact strength of the PP-R composites annealed at 120 ℃ for 6 h was relatively high at 74.73 k J/m^2, which was 16.8% higher than that of the samples annealed at 80 ℃ for 6 h. At low temperatures（-30-0 ℃）, the impact strength ranged from approximately 13.31 k J/m^2 to 54.4 k J/m^2. In addition, the annealing process conducted at 120 ℃ for 6 h improved the crystalline structure and low-temperature toughness of the PP-R composites and induced α-form to β-form crystal transformation. The work provides a possible method to reinforce and toughen the semicrystalline polymer at low temperatures（-30-0 ℃） by annealing.
