Synthesis and characterization of in-chain silyl-hydride functional SBR and self-crosslinking elastomer

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.

Anionic synthesis of binary random in-chain multi-functionalized poly(styrene/butadiene/isoprene and dimethyl [4-phenylvinyl)-phenyl]silane)(PS-DPESiH,PB-DPESiH,PI-DPESiH) copolymers

The binary random in-chain silyl-hydride multi-functionalized poly（styrene/butadiene/isoprene and dimethyl[4-（1-phenylvinyl） phenyl]silane） （PS-DPESiH, PB-DPESiH, PI-DPESiH） copolymers were successfully synthesized. These functionalized copo- lymers were prepared in hexane with n-BuLi as the initiator at 50℃ for 4 h. The silyl-hydride groups were introduced into polymer backbones quantitatively by living anionic polymerization. The copolymers were determined through 1H NMR, size exclusion chromatography （SEC） and differential scanning calorimetry （DSC） techniques, while the number of silyl-hych-ide groups was calculated and discussed.

In-chain functionalization through the combination of ring opening copolymerization and oxime "Click" reaction towards X-ray opaque polylactide copolymers

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.

Synthesis of Alkyne-functionalized Polymers via Living Anionic Polymerization and Investigation of Features during the Post-“thiol-yne” Click Reaction

"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.