Abstract:The effects of transesterification on the miscibility of poly(ethylene terephthalate)/poly(ethylene 2,6‐naphthalate) were studied. Blends were obtained by solution precipitation at room temperature to avoid transesterification during blend preparation. The physical blends and transesterified products were analyzed by wide‐angle x‐ray scattering, differential scanning calorimetry, and nuclear magnetic resonance spectroscopy. It was found that the physical blends are immiscible and when the extent of transesteri… Show more
“…When m i is replaced with w i , the weight fraction, eq 6, is still a good fit to the data. Our results in Figure do no agree with prior ones. , We believe that our data are correct and suppose that this discrepancy is due to the determination methods of T g . Dynamic mechanical analysis has advantages as compared to DSC in the location of the T g : large peaks in the tan δ are observed, as compared to small steps in the DSC curve around T g , as already pointed out by Brostow et al 5 Storage modulus E ‘ (a) and loss tangent tan δ (b) as a function of temperature for the PET/PEN blends prepared using a mixer at 290 °C and 100 rpm.…”
Section: Resultscontrasting
confidence: 95%
“…The glass transition temperature T g defined by the temperature corresponding to the peak of the tan δ curve in the glass transition region for all samples is listed in Table 3 and plotted as a function of PEN mole percent in Figure 6. Although some papers 1,8 reported that the Fox equation 13 holds well for PET/PEN blends, we observed a linear relationship between T g and PEN mole percent in the blends and can describe it by the following relation where m i indicates the mole fraction of each component. When m i is replaced with w i , the weight fraction, eq 6, is still a good fit to the data.…”
Section: Glass Transition Temperature and Cold Crystallization Of Pet...mentioning
confidence: 51%
“…Our results in Figure 6 do no agree with prior ones. 1,8 We believe that our data are correct and suppose that this discrepancy is due to the determination methods of T g . Dynamic mechanical analysis has advantages as compared to DSC in the location of the T g : large peaks in the tan δ are observed, as compared to small steps in the DSC curve around T g , as already pointed out by Brostow et al 11 Po et al 2 proposed that the T g of PENT random copolymers exhibits an almost linear variation with mole content of PEN and is almost independent of randomness.…”
Section: Glass Transition Temperature and Cold Crystallization Of Pet...mentioning
Exaggerated anticipatory anxiety is common in social anxiety disorder (SAD).
Neuroimaging studies have revealed altered neural activity in response to social stimuli in SAD, but fewer studies have examined neural activity during anticipation of feared social stimuli in SAD.
The current study examined the time course and magnitude of activity in threat processing brain regions during speech anticipation in socially anxious individuals and healthy controls (HC).
Method Participants (SAD n = 58; HC n = 16) underwent functional magnetic resonance imaging (fMRI) during which they completed a 90s control anticipation task and 90s speech anticipation task.
Exaggerated anticipatory anxiety is common in social anxiety disorder (SAD).
Neuroimaging studies have revealed altered neural activity in response to social stimuli in SAD, but fewer studies have examined neural activity during anticipation of feared social stimuli in SAD.
The current study examined the time course and magnitude of activity in threat processing brain regions during speech anticipation in socially anxious individuals and healthy controls (HC).
Method Participants (SAD n = 58; HC n = 16) underwent functional magnetic resonance imaging (fMRI) during which they completed a 90s control anticipation task and 90s speech anticipation task.
“…When m i is replaced with w i , the weight fraction, eq 6, is still a good fit to the data. Our results in Figure do no agree with prior ones. , We believe that our data are correct and suppose that this discrepancy is due to the determination methods of T g . Dynamic mechanical analysis has advantages as compared to DSC in the location of the T g : large peaks in the tan δ are observed, as compared to small steps in the DSC curve around T g , as already pointed out by Brostow et al 5 Storage modulus E ‘ (a) and loss tangent tan δ (b) as a function of temperature for the PET/PEN blends prepared using a mixer at 290 °C and 100 rpm.…”
Section: Resultscontrasting
confidence: 95%
“…The glass transition temperature T g defined by the temperature corresponding to the peak of the tan δ curve in the glass transition region for all samples is listed in Table 3 and plotted as a function of PEN mole percent in Figure 6. Although some papers 1,8 reported that the Fox equation 13 holds well for PET/PEN blends, we observed a linear relationship between T g and PEN mole percent in the blends and can describe it by the following relation where m i indicates the mole fraction of each component. When m i is replaced with w i , the weight fraction, eq 6, is still a good fit to the data.…”
Section: Glass Transition Temperature and Cold Crystallization Of Pet...mentioning
confidence: 51%
“…Our results in Figure 6 do no agree with prior ones. 1,8 We believe that our data are correct and suppose that this discrepancy is due to the determination methods of T g . Dynamic mechanical analysis has advantages as compared to DSC in the location of the T g : large peaks in the tan δ are observed, as compared to small steps in the DSC curve around T g , as already pointed out by Brostow et al 11 Po et al 2 proposed that the T g of PENT random copolymers exhibits an almost linear variation with mole content of PEN and is almost independent of randomness.…”
Section: Glass Transition Temperature and Cold Crystallization Of Pet...mentioning
Exaggerated anticipatory anxiety is common in social anxiety disorder (SAD).
Neuroimaging studies have revealed altered neural activity in response to social stimuli in SAD, but fewer studies have examined neural activity during anticipation of feared social stimuli in SAD.
The current study examined the time course and magnitude of activity in threat processing brain regions during speech anticipation in socially anxious individuals and healthy controls (HC).
Method Participants (SAD n = 58; HC n = 16) underwent functional magnetic resonance imaging (fMRI) during which they completed a 90s control anticipation task and 90s speech anticipation task.
Exaggerated anticipatory anxiety is common in social anxiety disorder (SAD).
Neuroimaging studies have revealed altered neural activity in response to social stimuli in SAD, but fewer studies have examined neural activity during anticipation of feared social stimuli in SAD.
The current study examined the time course and magnitude of activity in threat processing brain regions during speech anticipation in socially anxious individuals and healthy controls (HC).
Method Participants (SAD n = 58; HC n = 16) underwent functional magnetic resonance imaging (fMRI) during which they completed a 90s control anticipation task and 90s speech anticipation task.
“…The plot shows that theoretical expression (10) is closely followed and a transesterification kinetic rate constant of 0.028 37 min -1 is obtained. This value is very close to the rate constant 0.029 75 min -1 obtained under typical processing conditions for the same polyester blend 6 and 2-fold larger than the same blend system annealed at 280 °C in the DSC cell (recalculated on the basis of the raw data from ref ). This comparison indicates that our transesterification kinetics is close to the extrusion.…”
Exaggerated anticipatory anxiety is common in social anxiety disorder (SAD).
Neuroimaging studies have revealed altered neural activity in response to social stimuli in SAD, but fewer studies have examined neural activity during anticipation of feared social stimuli in SAD.
The current study examined the time course and magnitude of activity in threat processing brain regions during speech anticipation in socially anxious individuals and healthy controls (HC).
Method Participants (SAD n = 58; HC n = 16) underwent functional magnetic resonance imaging (fMRI) during which they completed a 90s control anticipation task and 90s speech anticipation task.
Exaggerated anticipatory anxiety is common in social anxiety disorder (SAD).
Neuroimaging studies have revealed altered neural activity in response to social stimuli in SAD, but fewer studies have examined neural activity during anticipation of feared social stimuli in SAD.
The current study examined the time course and magnitude of activity in threat processing brain regions during speech anticipation in socially anxious individuals and healthy controls (HC).
Method Participants (SAD n = 58; HC n = 16) underwent functional magnetic resonance imaging (fMRI) during which they completed a 90s control anticipation task and 90s speech anticipation task.
“…The blend composition, however, seems to be the controlling factor for these properties. A study by Ihm10 and previous studies in our laboratory16 also showed that the sequence lengths of the blocks of terephthalate and naphthalate units in the PET/PEN blends are much longer than those of random copolymers, yet the blends within such regions of transesterification levels show properties similar to those of random copolymers. Within this range, miscible blends of PET and PEN are formed and blend properties can be represented by any selected blend of the same composition, regardless of the transesterification level.…”
Exaggerated anticipatory anxiety is common in social anxiety disorder (SAD).
Neuroimaging studies have revealed altered neural activity in response to social stimuli in SAD, but fewer studies have examined neural activity during anticipation of feared social stimuli in SAD.
The current study examined the time course and magnitude of activity in threat processing brain regions during speech anticipation in socially anxious individuals and healthy controls (HC).
Method Participants (SAD n = 58; HC n = 16) underwent functional magnetic resonance imaging (fMRI) during which they completed a 90s control anticipation task and 90s speech anticipation task.
Exaggerated anticipatory anxiety is common in social anxiety disorder (SAD).
Neuroimaging studies have revealed altered neural activity in response to social stimuli in SAD, but fewer studies have examined neural activity during anticipation of feared social stimuli in SAD.
The current study examined the time course and magnitude of activity in threat processing brain regions during speech anticipation in socially anxious individuals and healthy controls (HC).
Method Participants (SAD n = 58; HC n = 16) underwent functional magnetic resonance imaging (fMRI) during which they completed a 90s control anticipation task and 90s speech anticipation task.
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