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A poly(methyl methacrylate)-supported Pd0 nanocatalyst was successfully prepared from solution reaction of Pd(CH3COO)2 with a copolymer acid, poly(methyl methacrylate-ran-methacrylic acid) (MMA–MAA). The reaction was carried out in a benzene/methanol mixed solvent in the dark at room temperature (∼25 °C) in the absence of a typical chemical reductant. There was coordination between the Pd0 nanoclusters and MMA–MAA, resulting in Pd0 nanoclusters being stably and uniformly dispersed in the MMA–MAA matrix, with an average particle size of ∼2.5 ± 0.5 nm. Mechanistically, it can tentatively be proposed that PMMA-ionomerization of the Pd2+ ions produces intramolecular –2COO−–Pd2+ aggregate cross-links in the solution. On swelling of the chain-segments that are covalently bound via multiple C–C bonds, the resultant elastic forces cause instantaneous dissociation at the O–Pd coordination bonds to give transient bare (i.e., uncoordinated), highly-oxidative Pd2+ ions and H+-associative carboxylate groups, both of which rapidly scavenge electrons and protons, respectively, of the active α-H atoms abstracted from the methanol molecules of the solvent to make Pd0 nanoclusters supported by the re-formed MMA–MAA. The MMA–MAA acid copolymer, without itself undergoing any permanent chemical change, serves as a mechanical activator or catalyst for the mechanochemical reduction of Pd(CH3COO)2 under mild conditions. Compared with traditional Pd/C catalysts, this Pd0 nanocatalyst exhibited more excellent catalytic efficiency and reusability in the Heck reaction between iodobenzene and styrene, and it could be easily separated. The supported Pd0 nanocatalyst prepared using this novel and simple preparation method may display high-efficiency catalytic properties for other cross coupling reactions.

When a small-molecule ionic crystal is group-substituted with polymer chain-segments to form an ionomer, do its constrained ionic aggregates maintain ordered internal structures? This work presents, for a Na-salt sulfonated-polystyrene ionomer, reconciled TEM electron-diffraction schlieren textures and WAXS Bragg-type reflections from the ionic-aggregate nanodomains, which solidly prove the aggregates' internal (mono)crystalline order. The observed DSC endotherm of the ionomer, identified by WAXS as an order-disorder transition interior to its aggregates, gradually becomes enhanced over a 3-month, room-temperature physical aging process, indicating that the aggregates' ordering is a slow relaxation process in which the degree of order increases with time. This work corroborates an uncommon form of order, i.e., polymer-bound small-molecule ionic (quasi)crystal, which is supplementary to the order phenomena in small molecules, polymers, and liquid crystals.

A poly(styrene-ran-cinnamic acid) (SCA) containing 6.8 mol% of CA, with a w (∼217 000) comparable to commercial polystyrene (PS), was successfully synthesised via emulsion free-radical copolymerisation as evidenced by 1744 and 1703 cm−1 infrared peak occurrences, respectively characteristic of free and dimeric carboxyl CO stretches. Upon the interchain hydrogen bond cross-linking by CA, the impact toughness of the SCA was considerably improved by 47.2% against PS, the glass transition, heat deflection and Vicat softening temperatures were significantly enhanced until 117.0, 108.0 and 118.3 °C, respectively, compared with PS (95.2, 87.6 and 96.0 °C), while the extensional viscosities were near one order-of-magnitude higher than PS by which the temperature window required for appropriate melt-strengths would be greatly broadened. Meanwhile, the SCA displayed other properties basically analogous to PS. This work presents a modified PS, SCA, with enhanced toughness, heat resistance and melt strength that potentially extend its styrofoam and commodity applications.

A poly(methyl methacrylate)-supported Pd

A poly(styrene

A half-critical weight-average molecular weight ( M ¯ w ) (approximately 21,000 g mol−1), high-ion-content Zn-salt poly(styrene−ran−cinnamic-acid) (SCA−Zn) ionomer was successfully synthesized by styrene−cinnamic-acid (10.8 mol %) copolymerization followed by excess-ZnO melt neutralization. At 220 °C, the SCA−Zn’s viscosity was only approximately 1.5 magnitude orders higher than that of commercial polystyrene (PS) at 102 s−1, and the PS/SCA−Zn (5−40 wt %) melt blends showed apparently fine, two-phased morphologies with blurred interfaces, of which the 95/5 and 90/10 demonstrated Han plots suggesting their near miscibility. These indicate that any PS−(SCA−Zn) processability mismatch was minimized by the SCA−Zn’s half-critical M ¯ w despite its dense ionic cross-links. Meanwhile, the SCA−Zn’s Vicat softening temperature (VST) was maximized by its cross-linking toward 153.1 °C, from that (97.7 °C) of PS, based on its half-critical M ¯ w at which the ultimate glass-transition temperature was approximated. Below approximately 110 °C, the PS/SCA−Zn (0−20 wt %) were seemingly miscible when their VST increased linearly yet slightly with the SCA−Zn fraction due to the dissolution of the SCA−Zn’s cross-links. Nevertheless, the 60/40 blend’s VST significantly diverged positively from the linearity until 111.1 °C, revealing its phase-separated morphology that effectively enhanced the heat resistance by the highly cross-linked SCA−Zn. This work proposes a methodology of improving PS heat resistance by melt blending with its half-critical M ¯ w , high-ion-content ionomer.

A new heteropolyanion-based ionic () was synthesized by the reaction of molybdovanadophosphoric acid () with N-methylimidazole. [ showed a high catalytic activity in the oxidative desulfurization of sulfur-containing compounds in 1-methylimidazolium tetrafluoroborate () ionic liquid using 30% aqueous as the oxidant. The catalytic system was of high activity, simplified workup and flexible recyclability. The catalytic oxidation reactivity of sulfur-containing compounds decreased in the order dibenzothiophene (DBT) > 4,6-dimethyldibenzothiophene (4,6-DMDBT) > benzothiophene (BT). The influences of various parameters including reaction time (t) and temperature (T), catalyst dosage, and oxidant to sulfur molar ratio n(O)/n(S) on the desulfurization of model oil were investigated in details. 99.1% of DBT conversion in the model oil was achieved at atmospheric pressure under the optimal conditions: n(O)/n(S) = 4:1, , 100 min and molar ratio of catalyst to sulfur of 0.062. The ionic liquid can be recycled six times without significant decrease in activity.

In the paper, PEEK(poly (ether ether ketone)) was added to the epoxy resins as a modifier to improve thermal and mechanical properties of the cured resins. The heat effects of curing epoxy resin composites with PEEK were investigated by differential scanning calorimetry (DSC) technology and the morphologies of the fracture surface by scanning electron microscope (SEM). The relationship between the morphologies and mechanical properties were discussed. The results revealed that the thermal and mechanical properties of the modified epoxy resins, such as impact strengths, compress strengths and the flexural strengths achieved improvements to a certain extent, compared with those of neat epoxy resins. As the addition of PEEK is 6 wt%, the impact strength reaches the maximum of 19.lkJ/m2, Martin's temperature achieves 120°C.