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.

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 polyurethanes bearing carbosilane segments

RSC Advances ◽  
2016 ◽  
Vol 6 (97) ◽  
pp. 94803-94808
Author(s):  
Ayumu Karimata ◽  
Kozo Matsumoto ◽  
Takeshi Endo
Keyword(s):  
Thermal Stability ◽  
Glass Transition ◽  
Transition Temperature ◽  
Glass Transition Temperature ◽  
Synthesis And Characterization ◽  
And Storage ◽  
Lower Glass Transition Temperature

New polyurethanes bearing carbosilane segment (1a–c) were synthesized and found to exhibit lower glass transition temperature and storage moduli than corresponding reference polyurethanes 2a–c, while thermal stability was retained.

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.

Synthesis and characterization of Au, Pt supported on graphene aerogel catalysts for CO oxidation at low temperature

2021 ◽  
Vol 11 (1) ◽  
pp. 118-122
Author(s):  
Chuyen Phan Thi ◽  
Hang Tran Thi Thanh ◽  
Phong Pham Nam ◽  
Ha Vu Thi Thu
Keyword(s):  
Low Temperature ◽  
Ambient Temperature ◽  
Co Oxidation ◽  
Pt Nanoparticles ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
Graphene Aerogel ◽  
Highly Dispersed ◽  
Average Size

Au, Pt supported on graphene aerogel catalysts (PtAu/rGOA) with molar ratio of Pt and Au of 1:1, and total metal concentration of 5 % were successfully synthesized by hydrothermal method.  The obtained catalysts were characterized by Raman, XRD, XPS, HR-TEM, BET. It revealed that Au and Pt nanoparticles with average size of 3 – 5 nm were highly dispersed on aerogel graphene. The activity of these catalysts was tested  in CO oxidation. The results showed that the conversion of CO at ambient temperature was 100% during 25 minutes. Accordingly, PtAu/rGOA could be considered as a potential catalysts for CO oxidation at low temperature.

scholarly journals Synthesis and characterization of new complexes of Co+2 , Ni+2 , Cu+2 and Zn+2 with (Sodium acetate thio ) ethylene ligands

2013 ◽  
Vol 10 (3) ◽  
pp. 650-657
Author(s):  
Baghdad Science Journal
Keyword(s):  
Content Analysis ◽  
General Formula ◽  
Metal Content ◽  
Sodium Acetate ◽  
Magnetic Measurement ◽  
Synthesis And Characterization ◽  
Square Planar ◽  
Square Planar Complexes ◽  
Uv Visible

This research involves the preparation of new ligands 1,1,2,2- tetrakis (sodium acetate thio)ethylene(L1) and 1,1,2- tris(sodiumacetatethio) ethylene(L2), through the reaction of disodium thioglycolate) with tetra chloro ethylene or tri chloro ethylene in (1:4) or (1:3) moler ratio . Homodinucliar complexes of general formlu [M2(L1)] and [M2(L2)ClH2O] , when M= Co(II), Ni(II), Cu (II) and Zn(II) also mono nuclear complexes of general formula [M(L2)] . The prepared complexes were characterized using spectral method (UV/Visible/ IR) , metal content analysis , magnetic and atomic measurements . The spectral and magnetic measurement indicats that some complexes have tetrahedral or square planar complexes environtment .

Synthesis and characterization of hybrid films from hyperbranched polyester using a sol-gel process

2013 ◽  
Vol 131 (3) ◽  
pp. n/a-n/a ◽  
Author(s):  
Amélie Houel ◽  
Jocelyne Galy ◽  
Aurélia Charlot ◽  
Jean-François Gérard
Keyword(s):  
Sol Gel ◽  
Synthesis And Characterization ◽  
Hyperbranched Polyester ◽  
Hybrid Films ◽  
Sol Gel Process

Synthesis and Characterization of an Alendronate-Chitosan Conjugate

2011 ◽  
Vol 140 ◽  
pp. 53-57 ◽  
Author(s):  
Xiao Hong Shao ◽  
Ji Qing Xu ◽  
Yan Peng Jiao ◽  
Chang Ren Zhou
Keyword(s):  
Drug Delivery ◽  
Drug Delivery System ◽  
Synthesis And Characterization ◽  
Hydroxyl Groups ◽  
Amino Groups ◽  
H Nmr ◽  
Ft Ir ◽  
Novel Drug Delivery System ◽  
Novel Drug

The biomineral-binding alendronate-chitosan conjugate (Scheme 1) was developed as a novel drug delivery system. Alendronate was conjugated to the hydroxyl groups of chitosan, thereby maintaining the amino groups of chitosan intact. By means of FT-IR and 1H NMR, the characterization was conducted to confirm the successful synthesis of alendronate-chitosan conjugate.

Sign in / Sign up

Export Citation Format

Share Document