النشر العلمي

  • Synthesis and Characterization of A2 + B3 Type Hyperbranched Aromatic-Aliphatic Polyester with Carboxyl End Groups

New types of carboxyl-terminated hyperbranched polyesters (HBPEs) with aromatic-aliphatic structure
were synthesized by single step-melt polycondensation of adipic acid (as A2 monomer) and phloroglucinol (as
B3 monomer) as a core via A2 + B3 approach, at three different monomer mole ratios (A2/B3 = 1 : 1, 1.5 : 1, 2 :
1, respectively). FTIR spectroscopy indicated that the polymers contained hydroxyl groups, ester bonds, benzene
ring, methyl and methylene groups, which were in agreement with the expected HBPEs. The HBPEs have inherent
viscosities about 0.24 to 0.27 dL/g. The degree of branching of the HBPEs was estimated to be 0.45–0.49%
by 1H-NMR and 13C-NMR measurements. The melting temperature of HBPE-1, HBPE-2 and HBPE-3 were 154,
155 and 160°C respectively measured by differential scanning calorimetry (DSC). The synthesized polymers were
thermally stable; the thermogravimetric analysis (TGA) measurement revealed that HBPEs had 10% weight loss
at 310°C in nitrogen.

published in Russian Journal of Applied Chemistry

  • Properties of recycled poly (ethylene terephthalate) (PET)/hyperbranched polyester (HBPET) composite fibers

Hyperbranched polyester (HBPET) with aliphatic–aromatic structure was synthesized and extruded with recycled poly
(ethylene terephthalate) (RPET) chips obtained from used water bottles, with ratio of 0.5% and 1 wt% of HBPET.
Filament fibers from pure recycled PET (RPET-0) and (RPET-0.5 and RPET-1) composite were spun using a melt
spinning process and drawn by a thermal drawing process to improve their mechanical properties. The effects of
addition of HBPET on the properties of produced fibers as well as draw ratio are investigated by means of differential
scanning calorimetry (DSC), wide-angle X-ray diffraction (XRD), universal tensile analysis, and sonic velocity. It was
found that mechanical properties of the (RPET-0.5 and RPET-1) fibers were improved with respect to pure recycled PET
(PET-0) fibers. Moreover, the crystallinity of composites fibers was also increased with an increasing of HBPET content.
The improvement in mechanical properties may be due to the increase of orientation of fiber molecules along the fiber
axis. Moreover, addition of HBPET serves as lubricant within recycled PET matrix which increased its mechanical
properties.

published in The Journal of The Textile Institute

  • Non-isothermal crystallization kinetics and nucleation activity of hyperbranched polyester (HBPET) in recycled PET

The non-isothermal crystallization of pure recycled polyethylene terephthalate
(RPET) and its blends with 3 and 5 wt% hyperbranched polyester
(HBPET) were investigated by differential scanning calorimetry (DSC). The DSC
curves demonstrate that the melt-crystallization temperatures of the blends are
always higher than that of pure RPET regardless of the cooling rate. Their nonisothermal
crystallization kinetics was further analyzed with modified Avrami
equation, Ozawa equation and Mo method. The analysis reveals that the crystallization
half-time (t1/2) of the blends is shorter than pure RPET. The activation energy
of crystallization of RPET was also determined according to Kissinger method and
it is found to decrease remarkably in RPET-3 and RPET-5 blends. All the results
indicate that HBPET serves as an effective nucleating agent for RPET.

published in Polym. Bull.

  • Purification Stability and Release of siRNA from Magnetic siRNA Nanovectors (MSNs), Toward Breast Cancer Theranosis

published in New chemical and biological tools for targeting in cancer imaging and therapy workshop

  • Biosynthesis of 2-O-α-D-glucopyranosyl-L-ascorbic acid from Maltodextrin Catalyzed by Cyclodextrin Glucanotransferase from Bacillus sp. SK13.002

Cyclodextrin glucanotransferase from Bacillus sp. SK13.002 has specificity to maltodextrin as a glycosyl
donor for production of 2-O-α-D-glucopyranosyl-L-ascorbic acid. In the present investigation, the product was
analyzed by HPLC and the reaction parameters were optimized. The results showed that the optimum
reaction condition was pH 8 at 37C for 24 h with 1:1 maltodextrin to L-ascorbic acid ratio and 80 U/mL of
Cyclodextrin glucanotransferase. Under the above optimal conditions, the production of AA-2G was 6.3 g/L,
indicates that Cyclodextrin glucanotransferase from Bacillus sp. SK13.002 is an effective producer of AA-2G
compared to previous studies.

published in Journal of Academia and Industrial Research

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