Novel Degradable Polymer Networks Containing Acetal Components and Well-Defined Backbones

2010 ◽  
Vol 63 (10) ◽  
pp. 1497 ◽  
Author(s):  
Xin-Ce Sui ◽  
Yan Shi ◽  
Zhi-Feng Fu
Keyword(s):  
Addition Reaction ◽  
Polymer Networks ◽  
Strong Acid ◽  
Hydroxyl Group ◽  
Molar Ratio ◽  
Degradable Polymer ◽  
Reversible Addition ◽  
Raft Agent ◽  
Chain Transfer Polymerization ◽  
Copolymer Network

A novel copolymer network was successfully prepared by combining the reversible addition–fragmentation chain-transfer polymerization (RAFT) and addition reaction between hydroxyl and vinyloxy groups. 2-Hydroxyethyl methacrylate (HEMA) and methyl methacrylate (MMA) were copolymerized in 1,4-dioxane with 2,2′-azobisisobutyronitrile as initiator and 2-(ethoxycarbonyl)prop-2-yl dithiobenzoate as a RAFT agent. The molecular weight of poly(HEMA-co-MMA) was well controlled and the polydispersity was low. The hydroxyl group from the HEMA unit in the copolymer underwent an addition reaction with 1,4-cyclohexanedimethanol divinyl ether in the presence of pyridinium p-toluenesulfonate, generating a copolymer network with an acetal component in the crosslinking segment. The crosslinking time depended on the molar ratio of HEMA and MMA in the poly(HEMA-co-MMA). After being treated in strong acid, the copolymer network was able to be degraded owing to the acetal structure, but the backbone chains of poly(HEMA-co-MMA) remained intact.

scholarly journals CONSTRUCTING POLYSTYRENE BRUSHES ON TIO2 NANOPARTICLES BY IN SITU REVERSIBLE ADDITION FRAGMENTATION CHAIN TRANSFER POLYMERIZATION

2018 ◽  
Vol 54 (1A) ◽  
pp. 292
Author(s):  
Long Giang Bach
Keyword(s):  
Tio2 Nanoparticles ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Average Particle Size ◽  
Average Particle ◽  
Tio2 Nps ◽  
Reversible Addition ◽  
Raft Agent ◽  
Ft Ir ◽  
Chain Transfer Polymerization

This paper presents the preparation of polystyrene functionalized TiO2 nanoparticles using the reversible addition fragmentation chain transfer (RAFT) polymerization. The surface of TiO2 NPs with an average particle size of about 5 nm was modified by S-benzyl S’-trimethoxysilylpropyltrithiocarbonate in order to obtain the RAFT agent functionalized TiO2 NPs (TiO2-RAFT). Subsequently, styrene was radically polymerized through the immobilized RAFT agent on the silica surface, in the presence of 2,2’-azobisisobutylnitrile (AIBN) as an initiator, to achieve the TiO2-g-PS nanocomposite. The characteristics of the as-synthesized nanocomposite were determined using FT-IR, EDX, XPS, TGA, XRD, TEM and SEM analyses.

scholarly journals Synthesis and Characterization of NBR´s by RAFT Technique and their use as Rubber Precursor in ABS Type Resins

2017 ◽  
Vol 58 (2) ◽  
Author(s):  
Francisco Javier Enríquez-Medrano ◽  
Florentino Soriano-Corral ◽  
Pablo Acuña-Vázquez ◽  
Edgar N. Cabrera-Álvarez ◽  
Hened Saade-Caballero ◽  
...  
Keyword(s):  
Chain Transfer ◽  
Dynamic Mechanical Properties ◽  
Bulk Polymerization ◽  
Reversible Addition ◽  
Raft Agent ◽  
Rubber Component ◽  
Distribution Composition ◽  
Chain Transfer Polymerization

<p>Different rubbers based on polybutadiene were synthesized in solution by the reversible addition-fragmentation chain-transfer polymerization (RAFT) technique using 4-cyano-4-[(dodecylsulfanylthiocarbonyl)sulfanyl] entanoic acid as RAFT agent and 1,1’-azobiscyclohexanecarbonitrile (Vazo-88) as initiator. The results obtained in the polymerization of polybutadiene and poly(butadiene-<em>co</em>-acrylonitrile) (NBR) are discussed in terms of molecular weight distribution, composition and microstructure. Composition of polybutadiene in NBR´s was kept constant along the copolymerization, and the vinyl, <em>cis</em> and <em>trans</em> isomers are shown in values of around 12, 26 and 62% in all cases. Resulting rubbers were used to synthesize acrylonitrilebutadiene-styrene (ABS) type resins through an <em>in situ</em> bulk polymerization. Dynamic-mechanical properties and the morphology were analyzed in all the different ABS resins. In DMA analyses, the rubber component presented two transitions as well as an increase in the magnitude of the transition located around -75 °C, which is explained by the significant amount of SAN occlusions in the morphology, analyzed by TEM.</p>

Synthesis of Allyl Functionalized Telechelic PVP by Reversible Addition-Fragmentation Chain Transfer (RAFT) Polymerization

2014 ◽  
Vol 789 ◽  
pp. 235-239
Author(s):  
Song Tao Li ◽  
Dan Li ◽  
Chun Ju He
Keyword(s):  
Radical Polymerization ◽  
Chain Transfer ◽  
Raft Polymerization ◽  
Polymer Networks ◽  
Telechelic Polymers ◽  
Grafted Polymers ◽  
Reversible Addition ◽  
Nitroxide Mediated Polymerization ◽  
Chain Transfer Polymerization ◽  
Epoxy Groups

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).

scholarly journals Synthesis of aminated polystyrene and its self-assembly with nanoparticles at oil/water interface

e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 317-327
Author(s):  
Chenliang Shi ◽  
Ling Lin ◽  
Yukun Yang ◽  
Wenjia Luo ◽  
Maoqing Deng ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Self Assembly ◽  
Carbon Dots ◽  
Chain Transfer ◽  
Functionalized Polymers ◽  
Amino Groups ◽  
One Dimensional ◽  
Reversible Addition ◽  
Oil Water ◽  
Chain Transfer Polymerization

AbstractThe influence of density of amino groups, nanoparticles dimension and pH on the interaction between end-functionalized polymers and nanoparticles was extensively investigated in this study. PS–NH2 and H2N–PS–NH2 were prepared using reversible addition–fragmentation chain transfer polymerization and atom transfer radical polymerization. Zero-dimensional carbon dots with sulfonate groups, one-dimensional cellulose nanocrystals with sulfate groups and two-dimensional graphene with sulfonate groups in the aqueous phase were added into the toluene phase containing the aminated PS. The results indicate that aminated PS exhibited the strongest interfacial activity after compounding with sulfonated nanoparticles at a pH of 3. PS ended with two amino groups performed better in reducing the water/toluene interfacial tension than PS ended with only one amino group. The dimension of sulfonated nanoparticles also contributed significantly to the reduction in the water/toluene interfacial tension. The minimal interfacial tension was 4.49 mN/m after compounding PS–NH2 with sulfonated zero-dimensional carbon dots.

Well-Defined Vinyl Ketone-Based Polymers by Reversible Addition−Fragmentation Chain Transfer Polymerization

2007 ◽  
Vol 129 (33) ◽  
pp. 10086-10087 ◽  
Author(s):  
Chong Cheng ◽  
Guorong Sun ◽  
Ezat Khoshdel ◽  
Karen L. Wooley
Keyword(s):  
Chain Transfer ◽  
Vinyl Ketone ◽  
Reversible Addition ◽  
Chain Transfer Polymerization

The Use of Novel F-RAFT Agents in High Temperature and High Pressure Ethene Polymerization: Can Control be Achieved?

2007 ◽  
Vol 60 (10) ◽  
pp. 788 ◽  
Author(s):  
Markus Busch ◽  
Marion Roth ◽  
Martina H. Stenzel ◽  
Thomas P. Davis ◽  
Christopher Barner-Kowollik
Keyword(s):  
Molecular Weight ◽  
High Pressure ◽  
High Temperature ◽  
Degree Of Polymerization ◽  
Molecular Weight Distributions ◽  
High Pressure High Temperature ◽  
Reversible Addition ◽  
Weight Distributions ◽  
Raft Agent ◽  
Initial Results

Simulations are employed to establish the feasibility of achieving controlled/living ethene polymerizations. Such simulations indicate that reversible addition–fragmentation chain transfer (RAFT) agents carrying a fluorine Z group may be suitable to establish control in high-pressure high-temperature ethene polymerizations. Based on these simulations, specific fluorine (F-RAFT) agents have been designed and tested. The initial results are promising and indicate that it may indeed be possible to achieve molecular weight distributions with a polydispersity being significantly lower than that observed in the conventional free radical process. In our initial trials presented here (using the F-RAFT agent isopropylfluorodithioformate), a correlation between the degree of polymerization and conversion can indeed be observed. Both the lowered polydispersity and the linear correlation between molecular weight and conversion indicate that control may in principle be possible.

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