Biobased unsaturated polyesters containing trans-2-butene-1,4 -diol and various dicarboxylic acids: Synthesis, characterization, and thermo-mechanical properties

Author(s):  
Yang Yu ◽  
Sixiao Liu ◽  
Zhiyong Wei
Pharmaceutics ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 982
Author(s):  
Gustavo Carreño ◽  
Adolfo Marican ◽  
Sekar Vijayakumar ◽  
Oscar Valdés ◽  
Gustavo Cabrera-Barjas ◽  
...  

A series of hydrogels with a specific release profile of linezolid was successfully synthesized. The hydrogels were synthesized by cross-linking polyvinyl alcohol (PVA) and aliphatic dicarboxylic acids, which include succinic acid (SA), glutaric acid (GA), and adipic acid (AA). The three crosslinked hydrogels were prepared by esterification and characterized by equilibrium swelling ratio, infrared spectroscopy, thermogravimetric analysis, mechanical properties, and scanning electron microscopy. The release kinetics studies of the linezolid from prepared hydrogels were investigated by cumulative drug release and quantified by chromatographic techniques. Mathematical models were carried out to understand the behavior of the linezolid release. These data revealed that the sustained release of linezolid depends on the aliphatic dicarboxylic acid chain length, their polarity, as well as the hydrogel crosslinking degree and mechanical properties. The in vitro antibacterial assay of hydrogel formulations was assessed in an Enterococcus faecium bacterial strain, showing a significant activity over time. The antibacterial results were consistent with cumulative release assays. Thus, these results demonstrated that the aliphatic dicarboxylic acids used as crosslinkers in the PVA hydrogels were a determining factor in the antibiotic release profile.


1979 ◽  
Vol 21 (9) ◽  
pp. 2295-2305
Author(s):  
B.M. Zuyev ◽  
S.G. Stepanov ◽  
A.P. Filippova ◽  
Ye.V. Chistyakov

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Yeşim Müge Şahin ◽  
Gökhan Çaylı ◽  
Jesmi Çavuşoğlu ◽  
Emre Tekay ◽  
Sinan Şen

As an alternative resin to conventional synthetic unsaturated polyesters (UPEs), epoxidized maleinated castor oil (EMACO) was synthesized in two steps. For this purpose, castor oil was reacted with maleic anhydride at 70°C to obtain maleinated castor oil (MACO). Then, epoxidation of MACO was carried out by using a mixture of formic acid and hydrogen peroxide at 0–5°C. Then, the free carboxyl groups of the synthesized EMACO were further reacted with free epoxide groups of EMACO at 90°C. At the end of the reaction, an unsaturated polyester precursor-prepolymer was obtained (P-EMACO). FTIR and1H NMR spectroscopic techniques were used to characterize the monomers synthesized. The P-EMACO was then mixed with styrene and cross-linked in the presence of AIBN at 50°C. Thermal and mechanical properties of the final cross-linked product were investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA) techniques. The degradation onset temperature of the material at which cross-linked X-EMACO loses 5% of its weight was found to be 209°C. Its dynamicTgand storage modulus at 25°C were determined as 72°C and 1.08 GPa, respectively. These results are higher than some of the different oil based polymers reported in the literature.


2014 ◽  
Vol 607 ◽  
pp. 547-550
Author(s):  
Yi Chu Hsu ◽  
Po Yuan Cheng ◽  
Hsiao Wei Lee ◽  
Shun Fua Su

We investigated two processes to fabricate unsaturated polyesters, UP, to serve as a stamp to emboss a microfluidic chip to apply to a peristaltic micropump. The mechanical properties of UP are great to apply to vibration type micro-actuators. However, it’s rarely discussed academically. As a result, we proposed two processes developed and compared macro-and micro-scopically. It was first observed that process I of traditional UP curing process and process II of modified process can both replicate the geometries of microfludic chips well macroscopically. In addition, the former one has macroscopic defaults like cracks, bend, and separation between vessel and UP molds, while the latter one doesn’t. Optical microscope and confocal microscope are also applied to verify the replication effects microscopically. Again, both processes illustrate good replication results with variation of both lengths and areas all less than 10%, while process II has better geometries and lower deviation on different sites. The process I was proven that the averages of depth and widest width change rates for replication are-1.06% (between-4.15% and 2.89%) and-2.77% (between-6.93% and 0.67%), respectively. And, the replication results of process II shows also reasonable change and even smaller deviations that the averages of depth and widest width change rates are-4.77% (between-6.33% and-3.84%) and 1.53% (between 1.15% and 2.15%), respectively.


2020 ◽  
Vol 21 (10) ◽  
pp. 3674 ◽  
Author(s):  
Yuushou Nakayama ◽  
Kazumasa Watanabe ◽  
Ryo Tanaka ◽  
Takeshi Shiono ◽  
Norioki Kawasaki ◽  
...  

Poly(ester amide)s are attracting attention because they potentially have excellent thermal and mechanical properties as well as biodegradability. In this study, we synthesized a series of novel poly(ester amide)s by introducing γ-aminobutyric acid (GABA) regularly into polyesters, and investigated their properties and biodegradabilities. GABA is the monomer unit of biodegradable polyamide 4 (PA4). The new poly(ester amide)s were synthesized from the reaction of ammonium tosylate derivatives of alkylene bis(γ-aminobutylate) and p-nitrophenyl esters of dicarboxylic acids. All the obtained polymers showed relatively high melting temperatures (Tm). Their thermal decomposition temperatures were improved in comparison with that of PA4 and higher enough than their Tm. The poly(ester amide)s exhibited higher biodegradability in seawater than the corresponding homopolyesters. Their biodegradabilities in activated sludge were also studied.


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