“…The polyether used was poly(oxyhexane), also denoted poly(1,6 hexanediol) [poly (1,6 HD)], and was synthesized employing the procedure reported by Basterretxea et al 18 The self-condensation of the diol (1,6 hexanediol) was carried out, the polyether was synthesized by a multistep polymerization process, using methanesulfonic acid/ triazabicyclo[4.4.0]dec-5-ene as a noneutectic base organocatalyst.…”
Section: ■ Experimental Sectionmentioning
confidence: 99%
“…Synthesis of PET-mb-poly (1,6 HD) Copolymers. The synthesis of each copolymer was performed in a tubular Schlenk flask with a magnetic stirrer.…”
Section: ■ Experimental Sectionmentioning
confidence: 99%
“…DMT (1 equiv, 0.015 mol, 3.0 g) and EG (1.4 equiv, 0.021 mol, 1.3 g) were blended in the presence of the DBU/BA (5 mol % with respect to DMT) catalyst at 250 °C for 1.5 h at atmospheric pressure. Afterward, the previously synthesized telechelic poly(1,6 HD) was added to obtain copolymers of PET-mb-poly(1,6 HD) with different compositions of PET/poly (1,6 HD). To do the above, the quantities of DMT and EG were kept constant while the content of poly(1,6 HD) was varied as follows [PET/poly(1,6 HD), g of poly(1,6 HD)]: (68/32, 0.48 g), (64/36, 1.08 g), (61/39, 1.86), and (34/66, 4.34 g).…”
Section: ■ Experimental Sectionmentioning
confidence: 99%
“…A mixed solvent was used consisting in deuterated chloroform (CDCl 3 ) and TFA (8:1, v/v) to dissolve PET and PET-mb-poly(1,6 HD) copolymers. For poly (1,6 HD), deuterated chloroform (CDCl 3 ) was used. CDCl 3 was employed as a reference for all spectra.…”
Section: ■ Experimental Sectionmentioning
confidence: 99%
“…Combining two or more homopolymers to obtain new materials (copolymers) with properties different from those of the parent homopolymers is a frequently used strategy. 1 Poly(ethylene terephthalate) (PET) is a frequently used polymer for the manufacture of beverage bottles, amongst other multiple products. Therefore, it has been the subject of intensive research.…”
Double
crystalline multiblock copolymers exhibit two well-defined
melting temperatures associated with the two phases formed by their
constituent blocks. The crystalline superstructure formed in these
copolymers is complex and depends on the miscibility of both comonomers.
In this work, an innovative series of double crystalline poly(ethylene
terephthalate)-mb-poly(oxyhexane) multiblock copolymers
were prepared in one pot. Previously synthesized low molecular weight
poly(oxyhexane)telechelic diol and poly(ethylene terephthalate) (PET)
oligomers were reacted by transesterification using an organic catalyst
(1,8-diazabicyclo[5.4.0]undec-7-ene/benzoic acid), in a solvent-free
process. The copolymerization was demonstrated by 1H NMR
and 13C NMR spectroscopies, and the random distribution
of poly(oxyhexane) chains was confirmed. We found that all compositions
exhibited double crystallinity, but the crystallization of the copolymers
was strongly affected by the PET/poly(oxyhexane) composition. When
the PET content in the copolymer decreases, the crystallization and
melting temperatures of the poly(oxyhexane) phase decrease as well
as its crystallization rate. The poly(oxyhexane) content increases
induce similar changes in the PET phase. PET and poly(oxyhexane) chain
segments form a one-phase melt according to small-angle X-ray scattering
(SAXS). When the material is cooled from the melt, the PET phase crystallizes
first (at higher temperatures), forming superstructural (micrometer
size spherulites) templates. Upon further cooling, the crystallization
of poly(oxyhexane) lamellae occurs, within the interlamellar regions
of PET spherulitic templates. Furthermore, during crystallization
of the copolymer, the amorphous regions of both components undergo
phase separation, as evidenced by the presence of two T
g’s. Polarized light optical microscopy/atomic
force microscopy studies were performed and demonstrated the presence
of microspherulitic morphology in the whole composition range. Considering
all results, including temperature-dependent synchrotron SAXS/wide-angle
X-ray scattering, we demonstrate the ability of poly(oxyhexane) to
crystallize upon cooling within the previously formed PET spherulitic
templates. Hence, these copolymers form complex double crystalline
spherulitic superstructures which contain two amorphous and two crystalline
interlamellar phases.
“…The polyether used was poly(oxyhexane), also denoted poly(1,6 hexanediol) [poly (1,6 HD)], and was synthesized employing the procedure reported by Basterretxea et al 18 The self-condensation of the diol (1,6 hexanediol) was carried out, the polyether was synthesized by a multistep polymerization process, using methanesulfonic acid/ triazabicyclo[4.4.0]dec-5-ene as a noneutectic base organocatalyst.…”
Section: ■ Experimental Sectionmentioning
confidence: 99%
“…Synthesis of PET-mb-poly (1,6 HD) Copolymers. The synthesis of each copolymer was performed in a tubular Schlenk flask with a magnetic stirrer.…”
Section: ■ Experimental Sectionmentioning
confidence: 99%
“…DMT (1 equiv, 0.015 mol, 3.0 g) and EG (1.4 equiv, 0.021 mol, 1.3 g) were blended in the presence of the DBU/BA (5 mol % with respect to DMT) catalyst at 250 °C for 1.5 h at atmospheric pressure. Afterward, the previously synthesized telechelic poly(1,6 HD) was added to obtain copolymers of PET-mb-poly(1,6 HD) with different compositions of PET/poly (1,6 HD). To do the above, the quantities of DMT and EG were kept constant while the content of poly(1,6 HD) was varied as follows [PET/poly(1,6 HD), g of poly(1,6 HD)]: (68/32, 0.48 g), (64/36, 1.08 g), (61/39, 1.86), and (34/66, 4.34 g).…”
Section: ■ Experimental Sectionmentioning
confidence: 99%
“…A mixed solvent was used consisting in deuterated chloroform (CDCl 3 ) and TFA (8:1, v/v) to dissolve PET and PET-mb-poly(1,6 HD) copolymers. For poly (1,6 HD), deuterated chloroform (CDCl 3 ) was used. CDCl 3 was employed as a reference for all spectra.…”
Section: ■ Experimental Sectionmentioning
confidence: 99%
“…Combining two or more homopolymers to obtain new materials (copolymers) with properties different from those of the parent homopolymers is a frequently used strategy. 1 Poly(ethylene terephthalate) (PET) is a frequently used polymer for the manufacture of beverage bottles, amongst other multiple products. Therefore, it has been the subject of intensive research.…”
Double
crystalline multiblock copolymers exhibit two well-defined
melting temperatures associated with the two phases formed by their
constituent blocks. The crystalline superstructure formed in these
copolymers is complex and depends on the miscibility of both comonomers.
In this work, an innovative series of double crystalline poly(ethylene
terephthalate)-mb-poly(oxyhexane) multiblock copolymers
were prepared in one pot. Previously synthesized low molecular weight
poly(oxyhexane)telechelic diol and poly(ethylene terephthalate) (PET)
oligomers were reacted by transesterification using an organic catalyst
(1,8-diazabicyclo[5.4.0]undec-7-ene/benzoic acid), in a solvent-free
process. The copolymerization was demonstrated by 1H NMR
and 13C NMR spectroscopies, and the random distribution
of poly(oxyhexane) chains was confirmed. We found that all compositions
exhibited double crystallinity, but the crystallization of the copolymers
was strongly affected by the PET/poly(oxyhexane) composition. When
the PET content in the copolymer decreases, the crystallization and
melting temperatures of the poly(oxyhexane) phase decrease as well
as its crystallization rate. The poly(oxyhexane) content increases
induce similar changes in the PET phase. PET and poly(oxyhexane) chain
segments form a one-phase melt according to small-angle X-ray scattering
(SAXS). When the material is cooled from the melt, the PET phase crystallizes
first (at higher temperatures), forming superstructural (micrometer
size spherulites) templates. Upon further cooling, the crystallization
of poly(oxyhexane) lamellae occurs, within the interlamellar regions
of PET spherulitic templates. Furthermore, during crystallization
of the copolymer, the amorphous regions of both components undergo
phase separation, as evidenced by the presence of two T
g’s. Polarized light optical microscopy/atomic
force microscopy studies were performed and demonstrated the presence
of microspherulitic morphology in the whole composition range. Considering
all results, including temperature-dependent synchrotron SAXS/wide-angle
X-ray scattering, we demonstrate the ability of poly(oxyhexane) to
crystallize upon cooling within the previously formed PET spherulitic
templates. Hence, these copolymers form complex double crystalline
spherulitic superstructures which contain two amorphous and two crystalline
interlamellar phases.
Antimicrobial resistance is a global problem due to widespread evolution of resistant pathogens in both health care and community. Polymeric quaternary ammonium and imidazolium chlorides are well known for their...
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