"Synthesis and photochromic behavior of spiro-pyran functionalized styrene-butadiene block copolymer"
Using active anionic solution polyme-rization technology, a styrene-butadiene block copolymer (PVPDMS-b-PB) functionalized with silicon-hydride groups was synthesized via feed distribution method. Gel permeation chromatography was employed to analyze the number-average molecular weight and polydisp...
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| Format: | Article |
| Language: | zho |
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Editorial Office of China Synthetic Rubber Industry
2025-01-01
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| Series: | Hecheng xiangjiao gongye |
| Subjects: | |
| Online Access: | http://hcxjgy.paperopen.com/oa/DArticle.aspx?type=view&id=202501004 |
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| Summary: | Using active anionic solution polyme-rization technology, a styrene-butadiene block copolymer (PVPDMS-b-PB) functionalized with silicon-hydride groups was synthesized via feed distribution method. Gel permeation chromatography was employed to analyze the number-average molecular weight and polydispersity index, revealing that PVPDMS-b-PB exhibited a unimodal, narrow distribution with a controllable molecular weight. In PVPDMS-b-PB, the molecular weight of the PVPDMS block remained constant, while the mole-cular weight of the PB block gradually increased. Further, an alkyne-functionalized spiro-pyran monomer (SP-Yne) was designed and synthesized. At room temperature, the silicon-hydride addition reaction between SP-Yne and PVPDMS-b-PB (number-average molecular weight 10.4 kg/mol) resulted in the formation of a structurally controlled spiro-pyran (SP)-functionalized styrene-butadiene block copolymer, namely (PVPDMS-g-SP)-b-PB. Structural ana-lysis of the monomer and polymer was carried out using nuclear magnetic resonance spectroscopy. The results showed that at room temperature, the silicon-hydride addition reaction between the silicon-hydride groups and the alkyne or double bonds was selective. The silicon-hydride groups in the PVPDMS block reacted with the alkyne groups in SP-Yne, avoiding reactions with the double bonds in the PB block, thereby preventing self-crosslinking between the silicon-hydride groups in PVPDMS and the double bonds in PB. UV spectroscopy was used to analyze the photochromic behavior of SP-Yne and (PVPDMS-g-SP)-b-PB, and the results showed significant photochromic behavior under 365 nm UV irradiation in chloroform, tetrahydrofuran, and toluene solutions. The maximum absorption wavelength exhibited a significant correlation with the polarity of the solution.
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| ISSN: | 1000-1255 |