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.

Synthesis and Characterization of Poly(butylenes succinate) with Control Different End-Group

2012 ◽  
Vol 430-432 ◽  
pp. 497-500 ◽  
Author(s):  
Chun Na Cui ◽  
Ji Tao Huang
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Thermal Properties ◽  
Acid Ester ◽  
Chemical Structure ◽  
Starting Material ◽  
Synthesis And Characterization ◽  
End Group

Poly (butylenes succinate) (PBS) was synthesized by using1, 4-butanediol and succinate as starting material, titanic acid ester and acetate as catalyst, and tried to improve PBS by changing end-group to carboxyl, hydroxyl and chlorine. The results of GPC showed, molecular weight of four kinds of polymer was all beyond seventy thousand; chemical structure of the polymer was measured by FTIR and nitrogen/sulfur/chlorine elementary analyzer; PBS controlled end-group had better thermal properties by DSC and TG; different end-group had influenced mechanical properties; and biodegradability experiment results showed biodegradable speed of PBS can be controlled by changing their end-group.

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 Novel Degradable Responsive Polyurethane Microsphere

2013 ◽  
Vol 750-752 ◽  
pp. 1271-1275 ◽  
Author(s):  
Lian Hai Shan ◽  
Yuan Yuan Cui ◽  
Shuai Huang ◽  
Zhi Bin Zhang
Keyword(s):  
Drug Delivery ◽  
Molecular Weight ◽  
Chemical Structure ◽  
Solvent Polarity ◽  
Toluene Diisocyanate ◽  
Synthesis And Characterization ◽  
The Novel ◽  
Swelling Ratio ◽  
Swelling Properties

The present study describes degradable polyurethane (PU) microspheres fabricated using toluene diisocyanate, polycaprolactone, polyethylene glycol, 2, 2-hydroxymethyl-2-propionic acid and triethylamine for drug delivery. The novel microspheres were synthesized using self-emulsion and condensed phase separation method. Fourier-Transform Infrared Spectrum analysis (FTIR) was performed revealing the chemical structure of polyurethane microspheres with special chains changing. Swelling properties influenced by solvent polarity, PEG content, PEG molecular weight, were evaluated, suggesting that the swelling ratio (SR) of PU microspheres increased with the increase in solvent polarity, PEG content and PEG molecular weight respectively.

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.

Synthesis and Characterization of Well-Defined 12,12-Ammonium Ionenes: Evaluating Mechanical Properties as a Function of Molecular Weight

2008 ◽  
Vol 41 (14) ◽  
pp. 5216-5222 ◽  
Author(s):  
Sharlene R. Williams ◽  
Erika M. Borgerding ◽  
John M. Layman ◽  
Wenqin Wang ◽  
Karen I. Winey ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Molecular Weight ◽  
Synthesis And Characterization

Synthesis and characterization of cellulose acetate naphthoate with good ultraviolet and chemical resistance

e-Polymers ◽  
2017 ◽  
Vol 17 (4) ◽  
pp. 333-340 ◽  
Author(s):  
Jun Song ◽  
Mei Liu ◽  
Zhanping Yang ◽  
Songwei Xu ◽  
Bowen Cheng ◽  
...  
Keyword(s):  
Cellulose Acetate ◽  
Chemical Structure ◽  
Chemical Resistance ◽  
Molar Ratio ◽  
Synthesis And Characterization ◽  
Cellulose Diacetate ◽  
H Nmr ◽  
Ultraviolet Resistance ◽  
Acid Catalyzed

AbstractCommercial cellulose diacetate with a degree of substitution (DS) of 2.45 was partly deacetylated to cellulose acetate (CA) with different DSs by acid-catalyzed hydrolysis and then reacted with 1-naphthoyl chloride (NpCl) to synthesize CA naphthoate (CANp). Fourier transform infrared and 1H-NMR were used to characterize the chemical structure of CANp. The DS of naphthoate moiety (DSCANp) could be varied from 0.18 to 0.98 by adjusting the molar ratio of –OH in CA unit to NpCl, the DS of CA (DSCA), and the reaction time and temperature. When DSCA was 2.01 and the molar ratio was 1:6, the maximum DSCANp of the product was achieved after a reaction at 80°C for 2 h. With the increase of DSCANp, the thermal stability decreased slightly whereas the anti-ultraviolet property was enhanced. Moreover, the obtained films containing CANp exhibited good ultraviolet resistance as well as chemical resistance.

Synthesis and characterization of photothermal antibacterial hydrogel with enhanced mechanical properties

2021 ◽  
Author(s):  
Shu bin Li ◽  
Xiao Wang ◽  
Jiang Zhu ◽  
Zhenyu Wang ◽  
Lu Wang
Keyword(s):  
Mechanical Properties ◽  
Hydrogen Bond ◽  
Fe3o4 Nanoparticles ◽  
Intermolecular Hydrogen Bond ◽  
Amide Bond ◽  
Synthesis And Characterization

In this work, using carboxyl-modified Fe3O4 nanoparticles as a photothermal agent, combining the chemical amide bond and intermolecular hydrogen bond crosslinking force, a photothermal hydrogel with enhanced mechanical properties was...

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.

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