Mesoionic carbene−iridium complex 1a has been investigated in the hydrogen isotope exchange (HIE) reaction of anilines. By employing 1 mol % of 1a as catalyst, anilines were selectively deuterated at the ortho-position with high deuteration levels. High ortho-selectivity was observed for anilines with various competing directing groups, which is in contrast with catalytic results of Kerr's catalysts.
In this study, we use implicit leadership theory to investigate how leader integrity, one of the most important traditional Chinese virtues, influences subordinates' organizational citizenship behaviour (OCB) in the Chinese context. The results of our survey reveal that leader integrity is associated with subordinates' OCB, and that this relationship is fully mediated by leader effectiveness. In addition, traditionality moderated the relationship between leader integrity and leader effectiveness; the relationship was significant among less traditional subordinates, but insignificant among more traditional subordinates. We conclude with a discussion of the theoretical and managerial implications for leaders in China.
Different from the traditional electrophilic polymerization
method
of thermoplastic elastomer, here, we adopted a new nucleophilic reaction
route, which did not need extreme high temperature and vacuum condition
to prepare a novel kind of semi-aromatic thermoplastic polyether amide
elastomers. First, difluoro-terminated semi-aromatic di-amide monomer
containing long chain ether (or 1,12-diaminododecane) was synthesized
through facile interfacial electrophilic substitution reaction. Then,
they were conducted to react with hydroquinone under atmospheric pressure
to yield polyether amide elastomer. Additionally, a small amount of
branched structure with trifluoro-terminated semi-aromatic amide monomer
was designed and further introduced into the polymer chain to adjust
the mechanical property. These semi-aromatic polyamide elastomers
were found to have excellent thermal properties with glass transition
temperature (T
g) of −39.5 to −34.8
°C, melting temperature (T
m) of 227.3–260.4
°C [which is much higher than that of the commercial products
such as Pebax5533 (Arkema, Paris, France) (T
m = 159 °C)], the 5% weight-loss temperature (T
d,5%) of 376.3–408.7 °C, and Vicat
softening temperature of 73.0–223.6 °C. The mechanical
properties of these resultant elastomers were good and can be controlled
with different copolymerization ratios of soft, hard, and branched
segments. The tensile strength, elongation at break, and elasticity
modulus were in the range of 9.8–23.4 MPa, 87.6–712.3%,
and 30.8–362.0 MPa, respectively. Besides, such a series of
copolymers showed a relatively low water absorption of 1.57–3.67%.
Interestingly, it was found that these resultant polyether amide elastomers
had better organic solvent resistance and acid–base corrosion
than the traditional TPAE-containing ester bond (−COO−)
in the polymer molecular chain. It can be potentially applied in the
chemical mechanical seal, especially in the high temperature and corrosion
environment.
Double polymeric grafted layer is constructed by two
steps of chemical
reaction, in which two polymers had been used, respectively polydopamine
(PDA) film and modified PASS (NH2–PASS) resin containing
amine group, as the interphase in carbon fiber reinforced poly(arylene
sulfide sulfone) (PASS) composite (CF/PASS) to work on enhancing the
interfacial property. All the test results of chemical components
and chemical structures on the carbon fiber surface show that the
double polymeric grafted layer was constructed successfully with PDA
and NH2–PASS chains. And obvious characteristics
of thin PDA film and a polymer layer can be clearly seen in the morphology
of modified carbon fiber. In addition to this, the obvious interphase
and change in the thickness of interphase have been observed in the
modulus distribution images of CF/PASS. The final superb performance
is achieved by PASS composites with a double polymeric grafted layer,
27.2% and 198.6% superior to the original PASS composite for IFSS
and ILSS, respectively. Moreover, the result also indicates that constructing
a double polymeric grafted layer on a carbon fiber surface is a promising
technique to modify carbon fiber for processing high-performance advanced
thermoplastic composites and is more environmental friendly as well
as convenient.
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