scholarly journals Influence of cyclodextrin on the solubility of a classically prepared 2-vinylcyclopropane macromonomer in aqueous solution

2012 ◽  
Vol 8 ◽  
pp. 1528-1535 ◽  
Author(s):  
Helmut Ritter ◽  
Jia Cheng ◽  
Monir Tabatabai
Keyword(s):  
Aqueous Solution ◽  
Carboxylic Acid ◽  
Graft Copolymer ◽  
Ring Opening ◽  
Main Chain ◽  
Double Bonds ◽  
Radical Ring ◽  
Unsaturated Polymer ◽  
End Group ◽  
Clouding Point

A macromonomer 5 consisting of a polymerizable vinylcyclopropane end group and a poly(N-isopropylacrylamide) (poly(NiPAAm)) chain was obtained from amidation of 1-ethoxycarbonyl-2-vinylcyclopropane-1-carboxylic acid (4) with an amino-terminated poly(NiPAAm) 3 as an example. This macromonomer 5 showed an LCST effect after complexation of the vinyl end group with ß-cyclodextrin in water. Via radical ring-opening copolymerization of 5 and NiPAAm a graft copolymer 8 with a clouding point of 32 °C was synthesized. The branched unsaturated polymer was treated with ozone to cleave the double bonds of the main chain.

Synthesis of Poly(acrylamide-Methacrylate)-G-Octylphenyl Polyoxyethylene and its Micellar Behavior in Aqueous Solution

2011 ◽  
Vol 239-242 ◽  
pp. 3337-3341
Author(s):  
Dong Xia Zhang ◽  
Wen Hui Hu ◽  
Fang Ping Wang ◽  
Lin Ke Xue ◽  
Xin Zhen Du
Keyword(s):  
Aqueous Solution ◽  
Graft Copolymer ◽  
Main Chain ◽  
Radical Copolymerization ◽  
Molar Ratio ◽  
Free Radical Copolymerization ◽  
Transmission Electron ◽  
Spherical Micelles ◽  
Acrylamide Monomer ◽  
Poly Acrylamide

An amphiphilic graft copolymer with poly(acrylamide-methacrylate) as a main chain and octylphenyl polyoxyethylene as side chains (P(AM-MA)-g-C8PhEO10) was successfully synthesized via free radical copolymerization. The structure and the composition of the graft copolymer were characterized by FTIR, 1H-NMR and elemental analysis (EA) in detail. The absolute molecular weight of the copolymer is 1.304×106, as determined by static light scattering (SLS). The molar ratio of acrylamide monomer to the macromonomer is 33:1 in the copolymer and 53 C8PhEO10 branch chains attach to a P(AM-MA) backbone. The micellar behavior of P(AM-MA)-g-C8PhEO10 was preliminarily studied by means of surface tension measurements, transmission electron microscope (TEM) in aqueous solution. It was found that the stable spherical micelles with core-shell structure are formed and polymolecular micelles are larger and more compact than monomolecular micelles. In addition, the graft copolymer has favorable thermal stability.

scholarly journals Truly Random Degradable Vinyl Copolymers via Photocontrolled Radical Ring-Opening Cascade Copolymerization

2021 ◽  
Author(s):  
Wenqi Wang ◽  
Zefeng Zhou ◽  
Xuanting Tang ◽  
Stephanie Moran ◽  
Jing Jin ◽  
...  
Keyword(s):  
Sulfur Dioxide ◽  
Ring Opening ◽  
Main Chain ◽  
Radical Ring ◽  
Polymer Backbone ◽  
Vinyl Polymers ◽  
Powerful Approach ◽  
Chain Composition ◽  
Promising Solution

Degradable vinyl polymers by radical ring-opening polymerization have become a promising solution to the challenges caused by the widespread use of non-degradable vinyl plastics. However, achieving even distribution of labile functional groups in the backbone of degradable vinyl polymers remains challenging. Herein, we report a photocatalytic approach to truly random degradable vinyl copolymers with tunable main-chain composition via radical ring-opening cascade copolymerization (rROCCP). The rROCCP of the macrocyclic allylic sulfone and acrylates or acrylamides mediated by visible light at ambient temperature achieved near-unity reactivity ratios of both comonomers over the entire range of the comonomer compositions and afforded truly random vinyl copolymers with degradable units evenly distributed in the polymer backbone. Experimental and computational evidence revealed an unusual reversible inhibition of chain propagation by in situ generated sulfur dioxide, which was successfully overcome by reducing the solubility of sulfur dioxide in the reaction mixture. This study provided a powerful approach to truly random degradable vinyl copolymers with tunable main-chain labile functionalities and comparable thermal and mechanical properties to traditional non-degradable vinyl polymers.

Main-chain degradable star polymers comprised of pH-responsive hyperbranched cores and thermoresponsive polyethylene glycol-based coronas

2018 ◽  
Vol 9 (39) ◽  
pp. 4824-4839 ◽  
Author(s):  
Ulrike Wais ◽  
Lohitha Rao Chennamaneni ◽  
Praveen Thoniyot ◽  
Haifei Zhang ◽  
Alexander W. Jackson
Keyword(s):  
Polyethylene Glycol ◽  
Ring Opening ◽  
Main Chain ◽  
Star Polymers ◽  
Hyperbranched Polymers ◽  
Ph Responsive ◽  
Radical Ring ◽  
Ketene Acetal

Dual stimuliresponsive main-chain degradable star hyperbranched polymers have been synthesized via cyclic ketene acetal radical ring-opening and RAFT-based methacrylate copolymerization.

scholarly journals Development of an Environmentally Friendly Resist-Removal Process Using Wet Ozone

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Hideo Horibe ◽  
Yousuke Goto
Keyword(s):  
Plastic Deformation ◽  
Carboxylic Acid ◽  
Ion Implantation ◽  
Main Chain ◽  
Side Chain ◽  
Double Bonds ◽  
Removal Rates ◽  
Chemical Structures ◽  
Tof Sims ◽  
Ion Implanted

We investigated the removal of polymers with various chemical structures and the removal of ion-implanted resists using wet ozone. The removal rates of polymers that have carbon-carbon (C–C) double bonds in the main chain were high. The main chain of these polymers may be decomposed. The removal rates of polymers that have C–C double bonds in the side chain were low. The benzene ring in the side chain changes into carboxylic acid, so their ability to dissolve in water increased. The polymers without C–C double bonds were not removed. Removal of B and P ion-implanted resists became difficult with increasing acceleration energy of ions at implantation. The resist with plastic-deformation hardness that was twice as hard as that of nonimplanted resist should be removed similarly to nonimplanted resist. Using TOF-SIMS, we clarified that the molecule of cresol novolak resin was destroyed and carbonized by ion implantation.

Recent Advances in Transition Metal Catalyzed C-H Functionalization Reactions Involving Aza/Oxabicyclic Alkenes

Synthesis ◽  
2021 ◽  
Author(s):  
Masilamani Jeganmohan ◽  
Pinki Sihag
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Ring Opening ◽  
Bond Activation ◽  
Considerable Progress ◽  
Double Bonds ◽  
Facial Selectivity ◽  
Ring Opening Reactions ◽  
Metal Catalyzed

Bicyclic alkenes, including Oxa- and azabicyclic alkenes can be readily activated by using transition-metal complexes with facial selectivity, because of the intrinsic angle strain on carbon-carbon double bonds of these unsymmetrical bicyclic systems. During last decades considerable progress has been done in the area of ring-opening of bicyclic strained ring by employing the concept of C-H activation. This Review comprehensively compiles the various C-H bond activation assisted reactions of oxa- and azabicyclic alkenes, viz., ring-opening reactions, hydroarylation as well as annulation reactions.

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