Functional in-chain silyl-hydride （Si-H） SBR copolymers of 4-vinyiphenyldimethylsilanol （VPDMS） and butadiene were synthesized by living anionic polymerization, in which active group Si-H was not lost and its cont...Functional in-chain silyl-hydride （Si-H） SBR copolymers of 4-vinyiphenyldimethylsilanol （VPDMS） and butadiene were synthesized by living anionic polymerization, in which active group Si-H was not lost and its content was controllable. Corresponding self-crosslinking elastomers were obtained by hydrosilation of Si-H group with vinyl bonds in chain. The copolymers and elastomers were characterized by 1a NMR, size exclusion chromatography （SEC）, Fourier transform infrared （FTIR） spectroscopy, differential scaskning calorimetry （DSC）, and thermogravimetry analysis （TGA） techniques.展开更多
X-ray imaging functionalization of biodegradable polyesters is a great demand and challenge in biomedical applications.In this work,a strategy of in-chain functionalization through the combination of ring opening copo...X-ray imaging functionalization of biodegradable polyesters is a great demand and challenge in biomedical applications.In this work,a strategy of in-chain functionalization through the combination of ring opening copolymerization and oxime "Click" postfunctionalization was developed towards X-ray opaque polylactide copolymers.A functionalized cyclic carbonate was first synthesized and used as comonomer of polylactide copolymers,which were subjected to postfunctionalization of oxime "Click" reaction towards iodinated polylactide copolymers.The chemical structure and physical properties of the target products were traced and confirmed.In vitro cytotoxicity evaluation with 3T3-Swiss albino by Alamar blue demonstrated a low cytotoxicity.The X-ray radiopacity was analyzed by Micro-CT and quantified by Hounsfield Units value,which could be tailorable by the feedstock.It is a promising X-ray visible implantable biomaterial in biomedical applications.展开更多
"Thiol-yne" click reaction has already been widely applied in synthesis and modification of new polymer structures or novel materials due to its specific features. However, in most studies, only chain-end st..."Thiol-yne" click reaction has already been widely applied in synthesis and modification of new polymer structures or novel materials due to its specific features. However, in most studies, only chain-end strategy was employed when using the di-addition feature of thiol-yne reaction, thus the in-chain di-addition strategy could endow us with a broader space to develop the synthesis of advanced polymers. Therefore, in this paper, the features of in-chain mono and di-addition were investigated when modifying the alkynefunctionalized polymers to prepare grafted polymers via thiol-yne click reaction. The results showed that it is almost impossible to obtain the in-chain di-adducts even under excess feeding of chain-end thiol-functionalized grafts, while only the in-chain mono-adducts could be obtained efficiently. Further researches investigated that the controlled grafting could be encountered when carrying out the thiol-yne click reaction between chain-end alkyne-functionalized polystyrenes and chain-end thiol-functionalized polystyrenes under proper feedings. Therefore, the effect of steric?hindrance might be the primary reason for the alternative grafting via thiol-yne click reaction between in-chain and chain-end alkyne-functionalized polymers.展开更多
基金sponsored by the National Natural Science Foundation of China(Nos.21034001 and 21174021)
文摘Functional in-chain silyl-hydride （Si-H） SBR copolymers of 4-vinyiphenyldimethylsilanol （VPDMS） and butadiene were synthesized by living anionic polymerization, in which active group Si-H was not lost and its content was controllable. Corresponding self-crosslinking elastomers were obtained by hydrosilation of Si-H group with vinyl bonds in chain. The copolymers and elastomers were characterized by 1a NMR, size exclusion chromatography （SEC）, Fourier transform infrared （FTIR） spectroscopy, differential scaskning calorimetry （DSC）, and thermogravimetry analysis （TGA） techniques.
基金financially supported by the National Natural Science Foundation of China(No.31500767)the Natural ScienceFoundation of Liaoning Province of China(No.20180510037)the Fundamental Research Funds for the Central Universities(No.DUT19LAB27)。
文摘X-ray imaging functionalization of biodegradable polyesters is a great demand and challenge in biomedical applications.In this work,a strategy of in-chain functionalization through the combination of ring opening copolymerization and oxime "Click" postfunctionalization was developed towards X-ray opaque polylactide copolymers.A functionalized cyclic carbonate was first synthesized and used as comonomer of polylactide copolymers,which were subjected to postfunctionalization of oxime "Click" reaction towards iodinated polylactide copolymers.The chemical structure and physical properties of the target products were traced and confirmed.In vitro cytotoxicity evaluation with 3T3-Swiss albino by Alamar blue demonstrated a low cytotoxicity.The X-ray radiopacity was analyzed by Micro-CT and quantified by Hounsfield Units value,which could be tailorable by the feedstock.It is a promising X-ray visible implantable biomaterial in biomedical applications.
基金financially supported by the National Natural Science Foundation of China (Nos. 21871037, 21674017, andU1508204)
文摘"Thiol-yne" click reaction has already been widely applied in synthesis and modification of new polymer structures or novel materials due to its specific features. However, in most studies, only chain-end strategy was employed when using the di-addition feature of thiol-yne reaction, thus the in-chain di-addition strategy could endow us with a broader space to develop the synthesis of advanced polymers. Therefore, in this paper, the features of in-chain mono and di-addition were investigated when modifying the alkynefunctionalized polymers to prepare grafted polymers via thiol-yne click reaction. The results showed that it is almost impossible to obtain the in-chain di-adducts even under excess feeding of chain-end thiol-functionalized grafts, while only the in-chain mono-adducts could be obtained efficiently. Further researches investigated that the controlled grafting could be encountered when carrying out the thiol-yne click reaction between chain-end alkyne-functionalized polystyrenes and chain-end thiol-functionalized polystyrenes under proper feedings. Therefore, the effect of steric?hindrance might be the primary reason for the alternative grafting via thiol-yne click reaction between in-chain and chain-end alkyne-functionalized polymers.
