scholarly journals Tuning the physical properties of malleable and recyclable polyimine thermosets: the effect of solvent and monomer concentration

RSC Advances ◽  
2017 ◽  
Vol 7 (76) ◽  
pp. 48303-48307 ◽  
Author(s):  
Chengpu Zhu ◽  
Cally Xi ◽  
William Doro ◽  
Tianyi Wang ◽  
Xin Zhang ◽  
...  
Keyword(s):  
Physical Properties ◽  
Monomer Concentration ◽  
Polymerization Rate ◽  
Effect Of Solvent

We report the effect of solvent choice and polymerization rate on the physical properties of polyimine based malleable thermosets.

Effect of solvent volume on the physical properties of spray deposited nano needle structured Sn2S3thin films

2016 ◽  
Vol 20 (4) ◽  
pp. 307-311 ◽  
Author(s):  
D. Prabha ◽  
S. Ilangovan ◽  
V.S. Nagarethinam ◽  
A.R. Balu
Keyword(s):  
Physical Properties ◽  
Effect Of Solvent ◽  
Solvent Volume

Effect of solvent volume on the physical properties of undoped and fluorine doped tin oxide films deposited using a low-cost spray technique

2011 ◽  
Vol 50 (6) ◽  
pp. 722-733 ◽  
Author(s):  
G. Muruganantham ◽  
K. Ravichandran ◽  
K. Saravanakumar ◽  
A.T. Ravichandran ◽  
B. Sakthivel
Keyword(s):  
Physical Properties ◽  
Tin Oxide ◽  
Low Cost ◽  
Oxide Films ◽  
Effect Of Solvent ◽  
Spray Technique ◽  
Tin Oxide Films ◽  
Solvent Volume

Living free radical polymerization of styrene with 2-cyanoprop-2-yl dithionaphthalate as RAFT agent

e-Polymers ◽  
2003 ◽  
Vol 3 (1) ◽  
Author(s):  
Zhu Jian ◽  
Zhu Xiulin ◽  
Zhou Di ◽  
Chen Jianying
Keyword(s):  
Molecular Weight ◽  
Reaction Temperature ◽  
Raft Polymerization ◽  
Monomer Concentration ◽  
Gel Permeation Chromatography ◽  
Monomer Conversion ◽  
Bulk Polymerization ◽  
Polymerization Rate ◽  
Chain Extension ◽  
Raft Agent

Abstract The reversible addition-fragmentation chain transfer (RAFT) bulk polymerization of styrene was studied using 2-cyanoprop-2-yl dithionaphthalate (CPDN) as RAFT agent in the presence or absence of 2,2’-azoisobutyronitrile (AIBN). The results of both thermally and AIBN-initiated styrene (St) polymerizations show that St can be polymerized in a controlled way using CPDN as RAFT agent; i.e., the polymerization rate is first order with respect to monomer concentration, and molecular weight increases linearly with monomer conversion. The molecular weights obtained from gel permeation chromatography are close to the theoretical values and molecular weight distributions are relatively narrow (Mw/Mn < 1.2). It is confirmed by chain extension reaction that the polymer prepared via RAFT polymerization can be used as a macroRAFT agent. The effects of reaction temperature and mole ratios [St]0/[CPDN]0/[AIBN]0 on the polymerization were investigated. The results indicate that the reaction temperature has a positive effect on the polymerization rate, but little effect on molecular weight and molecular weight distribution, and the optimum mole ratios were found to be [CPDN]0/[AIBN]0 > 4/3 and [St]0/[CPDN]0 < 800.

Radiation polymerization of 2-hydroxyethyl methacrylate-vinyl pyrrolidone-water system

1988 ◽  
Vol 53 (6) ◽  
pp. 1242-1246
Author(s):  
Minoru Kumakura ◽  
Isao Kaetsu
Keyword(s):  
Glass Transition ◽  
Low Temperatures ◽  
Water System ◽  
Monomer Concentration ◽  
Temperature Curve ◽  
Irradiation Temperature ◽  
Polymerization Rate ◽  
Vinyl Pyrrolidone ◽  
Hydroxyethyl Methacrylate ◽  
Radiation Polymerization

Radiation polymerization of 2-hydroxyethyl methacrylate-vinyl pyrrolidone-water system at low temperature was studied. The polymerization rate-irradiation temperature curve had a maximum peak at near glass transition temperaure, and it was shifted to the site of high temperature with increasing monomer concentration. The polymerization rate in vinyl pyrrolidone at low temperatures was accelerated by the addition of water. The polymers obtained by radiation polymerization of 2-hydroxyethyl methacrylate-vinyl pyrrolidone-water system at low temperatures were a high hydrophilicity and had porous structure.

scholarly journals Density and shrinkage as guiding criteria for the optimization of the thermal conductivity of poly(urethane)-class aerogels

2019 ◽  
Vol 93 (1) ◽  
pp. 149-167 ◽  
Author(s):  
Sylwia Członka ◽  
Massimo F. Bertino ◽  
Jan Kośny ◽  
Nitin Shukla
Keyword(s):  
Thermal Conductivity ◽  
Physical Properties ◽  
Dynamic Compression ◽  
Monomer Concentration ◽  
Volume Ratio ◽  
Compression Modulus ◽  
Toluene Diisocyanate ◽  
Solubility Parameters ◽  
K Index ◽  
Freeze Dried

Abstract We investigated the effect of gelation solvent, monomer type, and monomer concentration on the physical properties of freeze-dried poly(urethane)-poly(isocyanurate) (PUR-PIR) aerogels, with particular emphasis on their thermal conductivity. It was found that the gelation solvent considerably affects aerogel morphology and physical properties. Aerogels with the lowest thermal conductivity were obtained using a mixture of tetrahydrofuran (THF) and acetonitrile, in a 50% volume ratio. The influence on thermal conductivity of polyol and isocyanate structure and of their concentration was also investigated. Rigid precursors, phloroglucinol (POL), and an aromatic polyisocyanate based on toluene diisocyanate (Desmodur RC) yielded the lowest thermal conductivity. Our results were compared with recent work reporting on parameters that could be used as predictors of thermal conductivity and other physical properties of organic aerogels. None of these parameters were found to be satisfactory predictors of aerogel properties. For example, no systematic correlation between solvent solubility parameters and aerogel properties was observed. We also examined the role of the K-index. This index, defined as the ratio between porosity and contact angle, was shown recently to be a good predictor of the properties of polyurea aerogels. While the thermal conductivity scaled with the K-index, the scaling was different for each of the isocyanate monomers considered in our experiments. Thermal conductivity, instead, scaled well with the product of density and shrinkage of aerogels, independent of monomer type. The reasons of this dependence on shrinkage and density are discussed, and the use of these parameters to guide experimentation on other systems is discussed. Physical properties such as static and dynamic compression modulus and thermal stability of the most promising formulations were also examined.

Effect of solvent volume on the physical properties of sprayed fluorine-doped zinc oxide thin films

2012 ◽  
Vol 47 (4) ◽  
pp. 429-436 ◽  
Author(s):  
G. Muruganantham ◽  
K. Ravichandran ◽  
K. Saravanakumar ◽  
K. Swaminathan ◽  
N. Jabena Begum ◽  
...  
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Physical Properties ◽  
Oxide Thin Films ◽  
Effect Of Solvent ◽  
Solvent Volume

Polymerization of styrene using 1,1,2,2-tetraphenyl-1,2- ethanediol as initiator in the presence of 2,2,6,6-tetramethyl- 1-piperidinyloxy

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Gang Wang ◽  
Xiulin Zhu ◽  
Dijun Hu ◽  
Zhengping Cheng ◽  
Jian Zhu
Keyword(s):  
Molecular Weight ◽  
Monomer Concentration ◽  
Bulk Polymerization ◽  
Polymerization Rate ◽  
First Order ◽  
Molecular Weights ◽  
Molecular Weight Distributions ◽  
Weight Distributions ◽  
End Groups

Abstract The bulk polymerization of styrene using 1,1,2,2-tetraphenyl-1,2-ethanediol as initiator in the presence of 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) was investigated. The results show that polymerization proceeded in a controlled/ ’living’ way, i.e., polymerization rate is first order with respect to monomer concentration. Molecular weights increase linearly with conversion and molecular weight distributions are relatively low (Mw/Mn = 1.10 - 1.35). Well-defined polystyrenes with α-hydrogen and TEMPO end groups were obtained.

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