Controlling Mechanical Properties of 3D Printed Polymer Composites through Photoinduced Reversible Addition-Fragmentation Chain Transfer (RAFT) Polymerization

2021 ◽  
Author(s):  
Xiaobing Shi ◽  
Jin Zhang ◽  
Nathaniel Alan Corrigan ◽  
Cyrille Boyer

Reversible addition-fragmentation chain-transfer (RAFT) polymerization has been widely exploited to produce homogeneous and living polymer networks for advanced material design. In this work, we incorporate silica nanoparticles (SNPs) into a...

2014 ◽  
Vol 576 ◽  
pp. 49-53
Author(s):  
Ren Chang Zeng ◽  
Jiang Cheng ◽  
Shou Ping Xu ◽  
Qin Liu ◽  
Xiu Fang Wen ◽  
...  

A series of poly (hydroxyethyl methacrylate)-g-polycarboxybetaine methacrylate ester (PHEMA-g-PCBMAE) hydrogels were synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization in the presence of crosslinker. Then differential scanning calorimetry (DSC) was used to characterize PHEMA-g-PCBMAE hydrogels. The compression stresses of these hydrogels were investigated to evaluate the mechanical properties. The mechanical study suggested that PHEMA-g-PCBMAE hydrogels presented improved mechanical strengths comparing with polycarboxybetaine methacrylate ester (PCBMAE) hydrogel. Besides, the antimicrobial properties of PHEMA-g-PCBMAE hydrogels also estimated by usingStaphylococcus aureusas a model bacterial.


2014 ◽  
Vol 789 ◽  
pp. 235-239
Author(s):  
Song Tao Li ◽  
Dan Li ◽  
Chun Ju He

Telechelic polymers have been explored widely because they are precursors for preparing multi-block copolymers, grafted polymers, star polymers, and polymer networks [1-2]. A variety of telechelic polymers with terminals like hydroxy, carboxylic, epoxy groups and carbon–carbon double bond have been prepared by controlled radical polymerization (CRP) techniques including nitroxide-mediated polymerization (NMP), atom transfer radical polymerization (ATRP) and reversible addition-fragmentation chain transfer polymerization (RAFT)[3-5].The CRP techniques can not only control the molecular weight but also can be carried out in the presence of many functional groups from monomers, initiators, or chain transfer agents (CTA).


2021 ◽  
Author(s):  
Siva Ponnupandian ◽  
Prantik Mondal ◽  
Thomas Becker ◽  
Richard Hoogenboom ◽  
Andrew B Lowe ◽  
...  

This investigation reports the preparation of a tailor-made copolymer of furfuryl methacrylate (FMA) and trifluoroethyl methacrylate (TFEMA) via reversible addition-fragmentation chain transfer (RAFT) polymerization. The furfuryl groups of the copolymer...


Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1164
Author(s):  
Angeliki Chroni ◽  
Thomas Mavromoustakos ◽  
Stergios Pispas

The focus of this study is the development of highly stable losartan potassium (LSR) polymeric nanocarriers. Two novel amphiphilic poly(n-butyl acrylate)-block-poly(oligo(ethylene glycol) methyl ether acrylate) (PnBA-b-POEGA) copolymers with different molecular weight (Mw) of PnBA are synthesized via reversible addition fragmentation chain transfer (RAFT) polymerization, followed by the encapsulation of LSR into both PnBA-b-POEGA micelles. Based on dynamic light scattering (DLS), the PnBA30-b-POEGA70 and PnBA27-b-POEGA73 (where the subscripts denote wt.% composition of the components) copolymers formed micelles of 10 nm and 24 nm in water. The LSR-loaded PnBA-b-POEGA nanocarriers presented increased size and greater mass nanostructures compared to empty micelles, implying the successful loading of LSR into the inner hydrophobic domains. A thorough NMR (nuclear magnetic resonance) characterization of the LSR-loaded PnBA-b-POEGA nanocarriers was conducted. Strong intermolecular interactions between the biphenyl ring and the butyl chain of LSR with the methylene signals of PnBA were evidenced by 2D-NOESY experiments. The highest hydrophobicity of the PnBA27-b-POEGA73 micelles contributed to an efficient encapsulation of LSR into the micelles exhibiting a greater value of %EE compared to PnBA30-b-POEGA70 + 50% LSR nanocarriers. Ultrasound release profiles of LSR signified that a great amount of the encapsulated LSR is strongly attached to both PnBA30-b-POEGA70 and PnBA27-b-POEGA73 micelles.


2011 ◽  
Vol 89 (3) ◽  
pp. 317-325 ◽  
Author(s):  
Binxin Li ◽  
Daniel Majonis ◽  
Peng Liu ◽  
Mitchell A. Winnik

We describe the synthesis of an end-functionalized copolymer of N-(2-hydroxypropyl)methacrylamide (HPMA) and N-hydroxysuccinimide methacrylate (NMS) by reversible addition–fragmentation chain transfer (RAFT) polymerization. To control the polymer composition, the faster reacting monomer (NMS) was added slowly to the reaction mixture beginning 30 min after initating the polymerization (ca. 16% HPMA conversion). One RAFT agent, based on azocyanopentanoic acid, introduced a –COOH group to the chain at one end. Use of a different RAFT agent containing a 4-amino-1,8-naphthalimide dye introduced a UV–vis absorbing and fluorescent group at this chain end. The polymers obtained had molecular weights of 30 000 and 20 000, respectively, and contained about 30 mol% NMS active ester groups.


1999 ◽  
Vol 32 (21) ◽  
pp. 6977-6980 ◽  
Author(s):  
Roshan T. A. Mayadunne ◽  
Ezio Rizzardo ◽  
John Chiefari ◽  
Yen Kwong Chong ◽  
Graeme Moad ◽  
...  

e-Polymers ◽  
2008 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiaoming Wan ◽  
Zhengbiao Zhang ◽  
Xiulin Zhu ◽  
Jian Zhu ◽  
Zhenping Cheng

AbstractThree azobenzene-based dithiocarbamates, 2-(phenylazo-phenoxycarbonyl) prop-2-yl 9H-carbazole-9-carbodithioate (APCDT), 2-(4-nitro-phenylazophenoxy- carbonyl)prop-2-yl 9H-carbazole-9-carbodithioate (ANPCDT), 2-(4-cyanophenylazo- phenoxy-carbonyl)pro-2-yl 9H-carbazole-9-carbodithioate (ACPCDT), were synthesized and used as RAFT agents in the polymerizations of styrene (St) and methyl methacrylate (MMA). The results showed that APCDT, ACPCDT and ANPCDT were effective RAFT agents for the polymerization of St. In the case of MMA, the polymerization showed hybrid behavior. The different substitutes on azobenzene moiety in dithiocarbamates did not show obvious influence on the controllability of the polymerizations. The UV and fluorescence spectra of RAFT agents and obtained azobenzene-terminated polymers were investigated


2004 ◽  
Vol 58 (11) ◽  
pp. 514-520
Author(s):  
Milena Avramovic ◽  
Lynne Katsikas ◽  
Branko Dunjic ◽  
Ivanka Popovic

The fundamentals of controlled radical polymerization are presented in this review. The paper focuses on reversible addition fragmentation chain transfer (RAFT) polymerization. The mechanism and specifics of this type of polymerization are discussed, as are the possibilities of synthesizing complex macro-molecular structures. The synthesis and properties of RAFT agents, of the general structure Z-C(=S)-S-R, are presented.


Langmuir ◽  
2003 ◽  
Vol 19 (14) ◽  
pp. 5559-5562 ◽  
Author(s):  
Brent S. Sumerlin ◽  
Andrew B. Lowe ◽  
Paul A. Stroud ◽  
Ping Zhang ◽  
Marek W. Urban ◽  
...  

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