Synthesis and Characterization of Poly(Aryl Ether Quinoxaline)s with Controlled Molecular Weight

2011 ◽  
Vol 391-392 ◽  
pp. 826-829
Author(s):  
Song Ya Zhang ◽  
Zhong Xiao Li ◽  
Jia Ling Pu
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Strong Acid ◽  
Decomposition Temperature ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
Aryl Ether ◽  
Good Solubility ◽  
Step Procedure

Novel poly(aryl ether quinoxaline)s (PEQs) were prepared via a two-step procedure. First, poly (ether benzil) (PEB) was synthesized by the polycondensation of 4,4’-difluorobenzil and 4,4’-isopropylidenediphenol.Then, PEB was reacted with 1,2-diaminobenzene and 4,4'-oxydibenzene-1,2-diamine to give the PEQs. The molecular weight of the PEQs could be adjusted easily by varying the molar ratio of 1,2-diaminobenzene to 4,4'-oxydibenzene-1,2-diamine. The PEQs exhibited good solubility in common organic solvents such as NMP, DMAc, DMF, cyclohexanone and chloroform. In addition, the PEQs also had high glass transition (Tg) temperatures and good thermal properties, with an initial thermal decomposition temperature above 475 oC and glass transition temperatures above 210 oC. They also exhibited excellent resistance to strong acid and alkali.

Synthesis and Characterization of Carboxyl-Terminated Hyperbranched Polyester

2014 ◽  
Vol 665 ◽  
pp. 327-330
Author(s):  
Shi Jie Niu ◽  
Jian Wang ◽  
Yu Qing Bai ◽  
Ming Tao Run
Keyword(s):  
Glass Transition ◽  
Sodium Acetate ◽  
Succinic Anhydride ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
Hydroxyl Groups ◽  
Hyperbranched Polyester ◽  
End Groups ◽  
Lower Glass Transition Temperature

In order to prepare carboxyl-terminated hyperbranched polyester (HBP-COOH), succinic anhydride was used to modify hydroxyl-terminated hyperbranched polyester (HBP-OH), and the influences of the solvents, catalysts and time on the product’s structure were investigated. When THF is used as the solvent, sodium acetate as the catalyst, the molar ratio of succinic anhydride and hydroxyl groups is 3:1, and the reaction time is 6 h at 65°C, the modification extent of the hydroxyl groups is about 99% with about 95% yield. HBP-COOH has much lower glass transition temperature than that of HBP-OH due to its long and flexible end-groups.

Controlled molecular weight poly(arylene ether benzimidazole)s endcapped with benzimidazole and ethynyl groups

1995 ◽  
Vol 7 (1) ◽  
pp. 41-53 ◽  
Author(s):  
J G Smith ◽  
J W Connell ◽  
E J Siochi ◽  
P M Hergenrother
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Synthesis And Characterization ◽  
Solvent Resistance ◽  
Arylene Ether

A series of controlled molecular weight poly(arylene ether benzimidazole)s (PAEBIs) endcapped with either benzimidazole, ethynyl or phenylethynyl groups was prepared and characterized. PAEBIs endcapped with either ethynyl or phenylethynyl groups were thermally cured to provide polymers with improved moisture and solvent resistance and higher glass transition temperature than PAEBIs without reactive endcaps. The synthesis and characterization of a series of PAEBIs endcapped with benzimidazole, ethynyl and phenylethynyl groups prepared at stoichiometric imbalances of 7 and 10 mol% are discussed.

Synthesis and Characterization of Star-Shaped Porphyrin-Cored Poly(L-lactide)

2011 ◽  
Vol 239-242 ◽  
pp. 1703-1706 ◽  
Author(s):  
Xiao Hui Dai ◽  
Wei Liu ◽  
Ya Fei Huang ◽  
Chang Ming Dong
Keyword(s):  
Molecular Weight ◽  
Photodynamic Therapy ◽  
Molecular Weight Distribution ◽  
Weight Distribution ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
Porphyrin Core

Star-shaped porphyrin-cored poly(L-lactide) (SPPLLA) was synthesized using a tetra-hydroxyethyl terminated porphyrin as a core initiator and 4-(Dimethylamino)pyridine (DMAP) as a catalyst in THF at 50 °C. The molecular weight of as-synthesized polymer were measured by GPC and1HNMR. It was found that the molecular weight of SPPLLA could be adjusted linearly by controlling the molar ratio of L-lactide to porphyrin core initiator, and the molecular weight distribution was reasonably narrow. Furthermore, SPPLLA polymers showed similar UV-vis spectra compared with porphyrin core initiator. Consequently, this will provide potentially porphyrin-cored poly(L-lactide) for photodynamic therapy.

Naphthalene-based poly(aryl ether)s. II. Synthesis and characterization of poly(ether ketone)s containing two 1,4-naphthylene moieties in the repeat unit

1997 ◽  
Vol 75 (10) ◽  
pp. 1346-1353 ◽  
Author(s):  
Zhi Yuan Wang ◽  
Peter W. Broughton
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Repeat Unit ◽  
Synthesis And Characterization ◽  
Transition Temperatures ◽  
Aryl Ether ◽  
Glass Transition Temperatures ◽  
Phenyl Sulfone ◽  
Ether Ketone

Two new monomers, 4-chloro-1-(4′-fluoro-1-naphthoyl)naphthalene and 1,4-bis(4′-fluoro-1′-naphthoyl)benzene, have been synthesized and polymerized with four different bisphenols to give two series of the naphthalene-based poly(ether ketone)s that are analogous to commercial PEEK and PEEKK. The effect of the introduction of one or two 1,4-naphthylene moieties, in the backbone of the repeat unit, on the glass transition temperatures has been studied. The glass transition temperatures usually increased by 20–45 °C upon replacing one 1,4-phenylene with one 1,4-naphthylene moiety. All new poly (ether ketone)s prepared in tetramethylene sulfone were amorphous, with the glass transition temperatures in a range of 212–273 °C. The polymer produced from 1,4-bis(4′-fluoro-1′-naphthoyl)benzene and 1,4-hydroquinone in phenyl sulfone as a solvent at 300 °C showed semicrystalline properties with a melting temperature of 310 °C. Keywords: naphthalene, poly(ether ketone)s, synthesis, characterization, glass transition temperature.

scholarly journals Synthesis and characterization of Bi-functional photorefractive polymers with high molecular weight and low glass transition temperature

2014 ◽  
Vol 32 (5) ◽  
pp. 577-586 ◽  
Author(s):  
Shu-fan Chen ◽  
Lian-lai Sun ◽  
Xuan Luo ◽  
Xiao-dong Jiang ◽  
Wei-dong Wu ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
High Molecular Weight ◽  
Synthesis And Characterization ◽  
Photorefractive Polymers

Synthesis and Characterization of PLA-Based Aliphatic-Aromatic Copolyesters: Effect of Diols

2008 ◽  
Vol 55-57 ◽  
pp. 785-788
Author(s):  
M. Namkajorn ◽  
Atitsa Petchsuk ◽  
Mantana Opaprakasit ◽  
Pakorn Opaprakasit
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Lactic Acid ◽  
Chemical Structure ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
Polycondensation Reaction ◽  
Dimethyl Terephthalate ◽  
Aromatic Species

PLA-based aliphatic aromatic copolyesters have been synthesized and characterized in order to incorporate the degradability of PLA and good mechanical properties of aromatic species. Synthesis of the copolymers was conducted by polycondensation of lactic acid with dimethyl terephthalate (DMT) and various diols using stannous(II) octoate as a catalyst. Three types of diols with different methylene lengths were employed, i.e., ethylene glycol (EG), propylene glycol (PG) and 1, 4-butanediol (BD). Effects of diols and comonomer molar ratio on the extent of polycondensation reaction and molecular weight of the resulting copolymers were investigated. Diacids and diol ratios of L-lactic acid (LLA), dimethyl terephthalate (DMT) and diol of 1/1/2, 1/2/4 and 2/1/2 were employed. Characterization of chemical structure, molecular weight and thermal and physical properties of the resulting copolymers were conducted by FTIR, NMR, and DSC.

scholarly journals Synthesis and characterization of different soybean oil-based polyols with fatty alcohol and aromatic alcohol

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 491-499
Author(s):  
Fukai Yang ◽  
Hao Yu ◽  
Yuyuan Deng ◽  
Xinyu Xu
Keyword(s):  
Molecular Weight ◽  
Soybean Oil ◽  
Retention Time ◽  
Ring Opening ◽  
Isoamyl Alcohol ◽  
Synthesis And Characterization ◽  
Intermolecular Force ◽  
H Nmr ◽  
Epoxy Groups

Abstract In this article, five kinds of soybean oil-based polyols (polyol-E, polyol-P, polyol-I, polyol-B, and polyol-M) were prepared by ring-opening the epoxy groups in epoxidized soybean oil (ESO) with ethyl alcohol, 1-pentanol, isoamyl alcohol, p-tert-butylphenol, and 4-methoxyphenol in the presence of tetrafluoroboric acid as the catalyst. The SOPs were characterized by FTIR, 1H NMR, GPC, viscosity, and hydroxyl numbers. Compared with ESO, the retention time of SOPs is shortened, indicating that the molecular weight of SOPs is increased. The structure of different monomers can significantly affect the hydroxyl numbers of SOPs. Due to the large steric hindrance of isoamyl alcohol, p-hydroxyanisole, and p-tert-butylphenol, SOPs prepared by these three monomers often undergo further dehydration to ether reactions, which consumes the hydroxyl of polyols, thus forming dimers and multimers; therefore, the hydroxyl numbers are much lower than polyol-E and polyol-P. The viscosity of polyol-E and polyol-P is much lower than that of polyol-I, polyol-B, and polyol-M. A longer distance between the molecules and the smaller intermolecular force makes the SOPs dehydrate to ether again. This generates dimer or polymers and makes the viscosity of these SOPs larger, and the molecular weight greatly increases.

scholarly journals Design of an n-type low glass transition temperature radical polymer

2021 ◽  
Author(s):  
Teng Chi ◽  
Siddhartha Akkiraju ◽  
Zihao Liang ◽  
Ying Tan ◽  
Ho Joong Kim ◽  
...  
Keyword(s):  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Synthesis And Characterization ◽  
Design Synthesis

We document the design, synthesis, and characterization of the first low glass transition temperature, n-type (i.e., preferentially-reduced) radical polymer.

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