scholarly journals Microwave-assisted in situ ring-opening polymerization of ε-caprolactone in the presence of modified halloysite nanotubes loaded with stannous chloride

RSC Advances ◽  
2022 ◽  
Vol 12 (3) ◽  
pp. 1628-1637
Author(s):  
Gang Yang ◽  
Rui Ma ◽  
Shifan Zhang ◽  
Ziying Liu ◽  
Dexuan Pei ◽  
...  
Keyword(s):  
Ring Opening ◽  
Catalytic Effect ◽  
Stannous Chloride ◽  
Halloysite Nanotubes ◽  
Ring Opening Polymerization ◽  
Composite Catalyst ◽  
Chain Growth ◽  
Hydroxyl Groups ◽  
Microwave Assisted

For the composite catalyst, there existed synergetic catalytic effect between the hydroxyl groups and the metal center. All chain growth simultaneously proceeded between the layers or on the surface of HNTs, conducting the in situ ROP.

TiCp2Cl-Catalyzed Living Radical and Ring Opening Polymerizations Initiated from Epoxides and Aldehydes in the Synthesis of Linear, Graft and Branched Polymers

2004 ◽  
Vol 856 ◽  
Author(s):  
Alexandru D. Asandei ◽  
Isaac W. Moran ◽  
Gobinda Saha ◽  
Yanhui Chen
Keyword(s):  
Electron Transfer ◽  
Ring Opening ◽  
Glycidyl Methacrylate ◽  
Ring Opening Polymerization ◽  
Branched Polymers ◽  
Single Electron Transfer ◽  
Radical Ring ◽  
Polymer Architectures ◽  
Complex Polymer

ABSTRACTTi(III)Cp2Cl-catalyzed radical ring opening (RRO) of epoxides or single electron transfer (SET) reduction of aldehydes generates Ti alkoxides and carbon centered radicals which add to styrene, initiating a radical polymerization. This polymerization is mediate in a living fashion by the reversible termination of growing chains with the TiCp2Cl metalloradical. In addition, polymers or monomers containing pendant epoxide groups (glycidyl methacrylate) can be used as substrates for radical grafting or branching reactions by self condensing vinyl polymerization. In addition, Ti alkoxides generated in situ by both epoxide RRO and aldehyde SET initiate the living ring opening polymerization of ε-caprolactone. Thus, new initiators and catalysts are introduced for the synthesis of complex polymer architectures.

scholarly journals Synthesis of polybenzoxazine/clay nanocomposites by in situ thermal ring-opening polymerization using intercalated monomer

2011 ◽  
Vol 49 (19) ◽  
pp. 4213-4220 ◽  
Author(s):  
Kubra Dogan Demir ◽  
Mehmet Atilla Tasdelen ◽  
Tamer Uyar ◽  
Asei William Kawaguchi ◽  
Atsushi Sudo ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Clay Nanocomposites

Lipase Catalyzed HEMA Initiated Ring-Opening Polymerization: In Situ Formation of Mixed Polyester Methacrylates by Transesterification

2008 ◽  
Vol 9 (2) ◽  
pp. 704-710 ◽  
Author(s):  
Mohamad Takwa ◽  
Yan Xiao ◽  
Neil Simpson ◽  
Eva Malmström ◽  
Karl Hult ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
In Situ Formation

Evaluation of intercalation and interaction in in-situ polymerized PLA-HNT bionanocomposites

2020 ◽  
pp. 096739112092779
Author(s):  
P Manju ◽  
P Santhana Gopala Krishnan ◽  
SK Nayak
Keyword(s):  
Electron Microscopy ◽  
Halloysite Nanotubes ◽  
Poly Lactic Acid ◽  
Resonance Spectroscopy ◽  
Hydroxyl Groups ◽  
Scanning Calorimetry ◽  
Transmission Electron Microscopy Analysis ◽  
Electron Microscopy Analysis ◽  
Microscopy Analysis

We report the in-situ synthesis of poly(lactic acid)–halloysite nanotubes (PLA-HNT) bionanocomposites, with a perspective to improve the interaction between PLA and HNT. Three PLA-HNT bionanocomposites with different HNT weight percentages were synthesized by polycondensation, followed by azeotropic distillation technique. Fourier transform infrared spectroscopy studies indicated the existence of hydrogen bonding between terminal hydroxyl groups of PLA and Si–O–Si groups present in the outer surface of HNT. Wide-angle X-ray diffraction, 29Si- and 27Al-nuclear magnetic resonance spectroscopy analysis confirmed the intercalation of PLA into HNT. Scanning electron microscopy analysis confirmed that there was no significant agglomeration and PLA matrix was found to be embedded with HNT. Transmission electron microscopy analysis also gave ample proof to substantiate the intercalation of PLA chains into HNT. Studies on zeta potential of PLA-HNT bionanocomposites, as compared with PLA, also confirmed the interactions between PLA and HNT. Single melting peak in differential scanning calorimetry analysis indicated the existence of one form of crystalline structure.

An injectable PEG-based hydrogel synthesized by strain-promoted alkyne–azide cycloaddition for use as an embolic agent

RSC Advances ◽  
2016 ◽  
Vol 6 (4) ◽  
pp. 2904-2909 ◽  
Author(s):  
Xin Su ◽  
Linlin Bu ◽  
Hui Dong ◽  
Shuangli Fu ◽  
Renxi Zhuo ◽  
...  
Keyword(s):  
Ring Opening ◽  
Ring Opening Polymerization ◽  
Embolic Agent ◽  
Rabbit Ear ◽  
Biodegradable Hydrogel

Cyclooctyne and azide functionalized PEGs are prepared by ring-opening polymerization. They form a biodegradable hydrogel in situ to temporarily block rabbit ear vessels.

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