Polymers
·
2021
·Vol. 13
·期 15
·2496
·
IF 4.329
Shiyou Tian,Jicong Zhang,Qiong Zhou,Limei Shi,Wenwen Wang,Dong Wang
We report photochromic polyamide 6 (PA6) which was synthesized by hydrolyzed ring-opening polymerization of ε-caprolactam with spiropyran (SP) embedded in the polymer chains. It indicated that crystallinity degree of the resulting copolymers was decreased since only PA6 segments can crystallize with increasing content of SP modifier. Meanwhile, toughness of photochromic PA6 was decreased. The photochromic property analysis indicated that the sample with more flexibility and more content of SP was more sensitive to UV light at the beginning of irradiation than other samples and its color after being irradiated for 1 min tended to reddish. Investigation revealed that the UV-vis absorbance of SP-PA6-3 had negligible decay after 10 cycles, which indicated SP-modified PA6 possessed excellent photoresponse reversibility and fatigue resistance.Keywords:photochromic;polyamide 6;spiropyran;structure and properties
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF POLYMERS AND THE ENVIRONMENT
·
2024
·
IF 4.7
Wang Guoqiang,Hui Yunfeng,Wei Deyu,Wang Yueying,Yu Yiheng,Shi Longqing,Zhang Mengke,Hu Jing
Poly(butylene succinate) (PBS), a biodegradable material, has excellent mechanical properties and processing properties. Brassylic acid (BA) is a kind of diacid with long chains derived from biomass. In this study, poly(butylene succinate-co-butylene brassylate) is synthesized to investigate the effects of BA on the structure and properties of PBS. The relationship between the melting temperature of copolyesters and the content of butylene brassylate units is V-shaped, which is typical of isodimorphic random copolyesters. Due to the introduction of BA, the density of unstable ester bonds in copolyesters gradually decreases and the initial thermal decomposition temperature of copolyesters gradually increases with the increase of BA. The dynamic mechanical analysis showed that the glass transition temperature of PBS was reduced by the introduction of BA. When the BA content is 25%, the copolyesters and PBS have the same crystal structure. When the BA content is 50–100%, the copolyesters and poly(butylene brassylate) have the same crystal structure, which indicates that the butylene brassylate units are easier to crystallize than the butylene succinate units. The ductility of copolyesters increases with the addition of BA. When the BA content is 50%, the elongation at break reaches the maximum (> 2000%). The copolyesters are suited for films due to high elongation at break.
研究领域:
材料科学
·
生物化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2022
·
IF 6.364
Kui Liu,Liang Shi,Xueying Wang,Cheng Liu,Jie Li,Yulong Liao,Lichuan Jin,Dainan Zhang,Huaiwu Zhang
Herein, Li + -enriched Li (1+ x )2 ZnTi 3 O 8 ceramics are prepared via the solid-phase methods. As x increases, the unit cell volume gradually increases, while the grain size initially increases and then decreases gradually. The Li (1+0.06)2 ZnTi 3 O 8 ceramics exhibit the best dielectric properties : ε r = 25.92, Q × f = 109534 GHz (@7.37 GHz, which is a 48 % increase compared with the stoichiometric counterpart.), and τ f = −8.21 ppm/°C. The complex chemical bond theory and Raman spectroscopy reveal that Ti-O bonds have a significant effect on the dielectric properties . An optimal Li + enrichment leads to an overall reduction in the distortion of the Li/ZnO 4 tetrahedra, resulting in a reduction in τ f . First-principles calculations demonstrate that a suitable excess of Li + leads to an increase in the band-gap as well as an enhanced electron cloud density in the internal space of the Li1/ZnO 4 tetrahedra, thereby increasing the Q × f . In summary, Li + -enriched Li (1+0.06)2 ZnTi 3 O 8 ceramics are promising for a wide array of applications in microwave communications.
研究领域:
材料科学
·
固态物理
✓ 已验证
DOI
高影响因子
POLYMER BULLETIN
·
2025
·
IF 4
Wang Guoqiang,Wang Yueying,Wei Deyu,Hui Yunfeng,Yu Yiheng,Zhang Mengke,Shi Longqing,Hu Jing
Polylactic acid (PLA) is a kind of bio-based polyester with high tensile strength and poor ductility. Poly(butylene sebacate-co-terephthalate) (PBSeT) is a kind of biodegradable polyester with good ductility. To improve the ductility of PLA, PBSeT with high molecular weight was synthesized and melt blended with PLA to obtain PLA/PBSeT blends with high ductility in this study. Their structures and properties were characterized by differential scanning calorimetry, thermogravimetric analysis (TGA), dynamic mechanical analysis (DMA), and scanning electron microscopy (SEM). Although SEM, DMA, and TGA suggested poor compatibility between PBSeT and PLA, PBSeT can still improve the ductility of PLA. When the PBSeT content was 30 wt%, the elongation at break of the blend increased to 85.9%. PBSeT debonds with the PLA matrix to form internal cavitation and the shear band to absorb a large amount of energy to induce plastic deformation. Meanwhile, PBSeT can reduce the complex viscosity of PLA.
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2019
·
IF 3.771
Zongqian Wang,Haiwei Yang,Zun Zhu
Tremendous attention has been paid to the structure and properties of silk fibroin/sodium alginate (SF/SA) composite films . However, there is no report devoted to study the formation of hydrogen bonds and their effects on the structures and properties. Herein, SF/SA blends with different mass ratios were obtained and the technic of Gaussian multi-peaks-fitting of Fourier transform infrared spectrum (FTIR) was used to analyze their hydrogen bonds. From the results, the existence of the intermolecular and intramolecular hydrogen bonds was manifested, and the relative strength of the intermolecular hydrogen bond enhanced with the increase of SA content. The contribution of the intermolecular hydrogen bonding was as follows: OH⋯O (ether) > OH … π > OH⋯N. Meanwhile, the increase of intermolecular hydrogen bonding led to the increase of apparent viscosity of the SF/SA blend solutions. Moreover, the relationship between the hydrogen bond and properties (e.g, crystallinity , thermal stability, mechanical properties, morphology and etc.) of SF/SA composite films with different mass ratios were analyzed in detail.
研究领域:
高分子材料
·
生物材料
·
纤维科学
·
光谱分析
·
材料物理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）