Synthesis and characterization of novel organosoluble aromatic copolyimides

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Jintian Yang ◽  
Wei Huang ◽  
Yongfeng Zhou ◽  
Deyue Yan ◽  
Xiaohang Wang
Keyword(s):  
Gel Permeation Chromatography ◽  
Polymer Chains ◽  
Polymerization Process ◽  
Synthesis And Characterization ◽  
Aprotic Solvents ◽  
Solution Casting ◽  
Molecular Weights ◽  
Gel Permeation ◽  
Dipolar Aprotic Solvents

AbstractA series of novel aromatic copolyimides was synthesized from pyromellitic dianhydride with the commercial diamine 4,4’-methylenebisaniline (MBA) and the diamine 4,4’-methylenebis(2-tert-butylaniline) (MBTBA) specially designed by ourselves. The solubility of the copolyimides in conventional solvents decreased with the mole ratio of MBTBA to MBA. When MBTBA/MBA was larger than 8/2, the copolyimides are soluble in low boiling point solvents (such as chloroform and tetrahydrofuran) and can form a transparent, flexible, tough film by solution casting. When MBTBA/MBA was between 7/3 and 5/5, the copolyimides are only soluble in dipolar aprotic solvents (such as dimethylformamide and N-methyl-2-pyrrolidone) and form films, too. The copolyimide was precipitated in m-cresol in the polymerization process when MBTBA/MBA was lower than 5/5. The number-average molecular weights of the soluble copolyimides measured by gel permeation chromatography were larger than 5.0·104 and the polydispersity index was higher than 1.5. Only one glass transition of these copolyimides was detected at around 350°C. The copolyimides did not show appreciable decomposition up to 400°C under air and 550°C under nitrogen, and their thermal stability increased a little with the introduction of MBA into the polymer chains.

Number- and Weight-Average Molecular Weights for Some Proanthocyanidin Polymers (Condensed Tannins)

1986 ◽  
Vol 39 (4) ◽  
pp. 557 ◽  
Author(s):  
LJ Porter
Keyword(s):  
Condensed Tannins ◽  
Laser Light ◽  
Gel Permeation Chromatography ◽  
Laser Light Scattering ◽  
Polymer Chains ◽  
Average Chain Length ◽  
Molecular Weights ◽  
Scattering Measurements ◽  
Gel Permeation ◽  
Derivatives Of

The number-average molecular weights (Mn) and weight-average molecular weights (Mw) for proanthocyanidin polymers (condensed tannins) have been measured by vapour pressure osmometry and low-angle laser light-scattering measurements in methanol. These confirm earlier findings (based on gel permeation chromatography of the peracetate derivatives of these polymers) that they are polydisperse. The results also indicate that the incidence of branching in the polymer chains increases as the average chain length increases.

Synthesis and characterization of novel polysiloxane based ABA-type triblock copolymers using ATRP

e-Polymers ◽  
2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Rajan B. Bodkhe ◽  
Dean C. Webster
Keyword(s):  
Radical Polymerization ◽  
Secondary Amine ◽  
Ring Opening ◽  
Triblock Copolymers ◽  
Gel Permeation Chromatography ◽  
Controlled Radical Polymerization ◽  
Synthesis And Characterization ◽  
Unique Material ◽  
Gel Permeation

Abstract Novel polysiloxane based ABA-type triblock copolymers having a secondary amine at the junction point were synthesized using a combination of ring opening equilibration polymerization (ROEP), Michael addition and atom transfer radical polymerization (ATRP). Polysiloxane based bifunctional ATRP macroinitiators were synthesized and subsequently used for controlled radical polymerization of t-butyl acrylate (t-BA) and sulfobetaine methacrylate (SBMA). Gel permeation chromatography (GPC) analysis of the triblocks based on t-BA showed high chain end functionality, due to the disappearance of peaks related to the macroinitiator. ROEP can be used to control the block length of the polysiloxane while ATRP can be used to control the chain length of the outer blocks, making the ABA- type triblock a unique material with secondary amine functionality which can be used for further reaction.

scholarly journals Synthesis and Characterization of Poly(aryleneethynylene)s and Their Corresponding Platinum-Linked Polymers

2011 ◽  
Vol 3 (3) ◽  
pp. 587-597 ◽  
Author(s):  
M. I. Hossain ◽  
D. Debnath ◽  
M. Younis ◽  
M. A. Bari ◽  
M. A. J. Miah
Keyword(s):  
Oxidative Coupling ◽  
Nmr Spectra ◽  
31P Nmr ◽  
Gel Permeation Chromatography ◽  
Degree Of Polymerization ◽  
Synthesis And Characterization ◽  
Organometallic Polymers ◽  
Organic Polymers ◽  
Gel Permeation

A series of thermally stable organic polymers [poly(2,5-diethynylpyridine] (5), [poly(1,4- diethynyl benzene)] (6), [poly(2,5-dialkyl-p-phenyleneethynylene)] (7), and [poly(p,p-diethynylbiphenyl)] (8), were synthesized by the reaction between diterminal aryleneethynylene, [HCCArCCH] {Ar = C5H5N (1); Ar = C6H6 (2); Ar = C6H4(CH3)2 (3); Ar = C6H4-C6H4 (4)} and CuCl in pyridine by Hay’s oxidative coupling method. Then the organometallic polymers [Ph (PnBu3)2Pt-C≡C-(Ar-C≡C-C≡C)n-Pt((PnBu3)2Ph] {Ar = C5H5N (9); Ar = C6H6 (10); Ar = C6H4(CH3)2 (11); Ar = C6H4-C6H4 (12)}   were synthesized by the reaction of organic polymers 5, 6, 7 and 8 with metal precursor (PnBu3)2 PtPhCl in diethylisopropileamine with good yield. These metal-linked polymers were characterized by IR, 1H-NMR, 13C-NMR and 31P-NMR spectra. Finally the molecular weight of the organometallic polymers (9, 10, 11 and 12) was determined by gel permeation chromatography (GPC). It is clearly observed from GPC that the polymers were synthesized with different degree of polymerization. Keywords:  Organometallic polymers; Hay’s Oxidative coupling; GPC. © 2011 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. doi: 10.3329/jsr.v3i3.7293               J. Sci. Res. 3 (3), 587-597 (2011)

Characterization of LARCTM-CPI 2 poly(amide acid) aging by gel permeation chromatography/differential viscometry

1995 ◽  
Vol 7 (1) ◽  
pp. 55-68 ◽  
Author(s):  
E J Siochi ◽  
S J Havens ◽  
P R Young ◽  
P M Hergenrother
Keyword(s):  
Molecular Weight ◽  
Fourier Transform ◽  
Infrared Spectroscopy ◽  
Gel Permeation Chromatography ◽  
Concentrated Solutions ◽  
Solution Property ◽  
Molecular Weights ◽  
Gel Permeation ◽  
Property Changes

A controlled-molecular-weight LARCr'-CPI 2 poly(amide acid) was synthesized to investigate solution property changes that result from aging'Both dilute and concentrated solutions were aged at five temperatures and periodically analysed over a 33 d period. Various molecular weight parameters were obtained by gel permeation chromatography in combination with differential viscometry. Chemical changes were also followed by Fourier transform infrared spectroscopy. The temperatures used allowed the calculation of the energy of activation associated with changes in weight and number average molecular weights.

Influence of Thermal Treatment on the Molecular Weights of Polyhydroxyalkanoate Containing 3-Hydroxyhexanoate

2013 ◽  
Vol 812 ◽  
pp. 250-253 ◽  
Author(s):  
Yoga Sugama Salim ◽  
Chin Han Chan ◽  
Kumar Sudesh ◽  
Seng Neon Gan
Keyword(s):  
Molecular Weight ◽  
Thermal Treatment ◽  
Gel Permeation Chromatography ◽  
Polymer Processing ◽  
Polymer Chains ◽  
Molecular Weights ◽  
Gel Permeation ◽  
Ftir Spectrometer ◽  
Major Reduction ◽  
End Group

With blooming interests in the research of biodegradable polyesters produced from microorganisms as well as polymer processing and technology, this study is intended to reveal the influence of thermal treatment on the molecular weight of poly (3-hydroxybutyrate-co-3 mol% 3-hydroxyhexanoate)/P(3HB-co-3 mol% 3HHx), a copolymer of polyhydroxyalkanoates (PHA). P(3HB-co-3 mol% 3HHx) was thermally treated using Differential Scanning Calorimeter and analyzed using Gel Permeation Chromatography and Attenuated Total Reflectance-Fourier transform infrared (ATR-FTIR) spectrometer. Results from gel permeation chromatography suggest a major reduction of molecular weight up to 50 % when P(3HB-co-3 mol% 3HHx) is exposed to 180 °C for 30 mins. The half-time degradation of P(3HB-co-3 mol% 3HHx) treated at 170 °C and 180 °C is 14.1 and 9.9 mins, respectively. FTIR spectroscopy shows an increase absorbance intensity of P(3HB-co-3 mol% 3HHx) after thermal treatment, indicating a formation of more alkenyl and carboxylic end-group in polymer chains due to random chain scissions.

scholarly journals Synthesis and Characterization of Easily Processable Polyaramides Containing Pendent Diamantan Moiety in the Main Chain

2008 ◽  
Vol 5 (2) ◽  
pp. 257-262 ◽  
Author(s):  
M. K. Mukul ◽  
P. K. Srivastava
Keyword(s):  
Main Chain ◽  
Gel Permeation Chromatography ◽  
Nitrogen Atmosphere ◽  
Direct Polycondensation ◽  
Molecular Weights ◽  
Gel Permeation ◽  
Thermal Stability Of ◽  
Tga Analysis ◽  
Carboxy Methyl

Three new polyamides were synthesized by direct polycondensation of 1-6 bis(carboxy methyl diamantan with three different aromatic amines in Nmethyl 2-pyrrolidine containing lithium chloride using triphenyl phosphate and pyridine as condensing agent. 1-6 bis(carboxy methyl)diamantan was prepared from 1-6 dibromo diamantan and structure was conformed by1H and13C NNR spectroscopy. A comparison of the effect for introducing bulky side group in the diamine contribution was evaluated. This polyamide had inherent viscosity of 0.57-1.18dL/g. It was found that all polyamides were soluble in polar aprotic solvents. Thermal stability of polymer was evaluated by TGA analysis. Molecular weights of all polyamides were determined by gel permeation chromatography. These have been found to be thermally stable up to 400°C with 1320% weight loss under nitrogen atmosphere.

Synthesis and characterization of polysilane precursors for silicon carbide fibers

1995 ◽  
Vol 10 (10) ◽  
pp. 2659-2667 ◽  
Author(s):  
Wayne R.I. Cranstone ◽  
Suzannc M. Bushnell-Watson ◽  
John H. Sharp
Keyword(s):  
Silicon Carbide ◽  
Alkali Metal ◽  
Gel Permeation Chromatography ◽  
Thermomechanical Analysis ◽  
Synthesis And Characterization ◽  
Silicon Carbide Fibers ◽  
Gel Permeation

A series of polysilanes was prepared by the alkali metal dechlorination of chlorosilane monomers, in which the overall functionality, F, of the reaction was varied. Starting monomers of functionality f = 2.0 and 3.0 were reacted together in various proportions to achieve values of F of 2.2, 2.35, and 2.5. In addition to varying the functionality of the reaction, three different difunctional monomers, dimethyldichlorosilane (DMDCS), diphenyldichlorosilane (DPDCS), and methylphenyldichlorosilane (MPDCS), and two trifunctional monomers, phenyltrichlorosilane (PTCS) and ethyltrichlorosilane (ETCS), were used. The effect of these changes on the yields of the polysilanes was determined, and the products were investigated by the use of thermogravimetry (TG), gel permeation chromatography (GPC), and thermomechanical analysis (TMA). The ability to spin a polysilane fiber was also assessed.

Synthesis and characterization of 4- and 6-arm star-shaped poly(ε-caprolactone)s

e-Polymers ◽  
2005 ◽  
Vol 5 (1) ◽  
Author(s):  
Michael A. R. Meier ◽  
Ulrich S. Schubert
Keyword(s):  
Ring Opening ◽  
Analytical Techniques ◽  
Gel Permeation Chromatography ◽  
Laser Desorption ◽  
Ring Opening Polymerization ◽  
Molecular Weights ◽  
H Nmr ◽  
Flight Mass Spectrometry ◽  
Gel Permeation

AbstractStar-shaped poly(ε-caprolactone) (PCL) polymers were synthesized and fully characterized by gel permeation chromatography, matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) as well as 1H NMR spectroscopy. First a series of four-armed PCLs with different molecular weights was prepared and analyzed with the mentioned analytical techniques revealing that the applied ring-opening polymerization was controlled and defined star-shaped polymers could be synthesized. Subsequently, also the synthesis of six-armed PCL polymers was investigated with the conclusion that also these starshaped polymers could be prepared in a controlled fashion.

Synthesis and characterization of 4-chloromethylstyrene polymers containing bulky organosilicon groups

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Kazem Dindar Safa ◽  
Mirzaagha Babazadeh
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Gel Permeation Chromatography ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Gel Permeation ◽  
Covalently Linked ◽  
C Nmr

Abstract The homopolymer of 4-chloromethylstyrene and its copolymers with styrene (in 1:3 and 1:1 mole ratio) were synthesized by bulk and solution freeradical polymerisations, respectively, at 70±1°C using α,α'-azoisobutyronitrile as an initiator. Highly sterically hindered tris(trimethylsilyl)methyl (Tsi) substituents were then covalently linked to the obtained homopolymer and copolymers. The polymers were characterized by IR, 1H NMR and 13C NMR, differential scanning calorimetry (DSC) and gel permeation chromatography. DSC showed that incorporation of Tsi substituents in the side chains of homopolymer and copolymers increases the rigidity of the polymers and, subsequently, their glass transition temperature.

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