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Broader applications of polymer hydrogels are largely constrained by their poor mechanical performance. Here, we report our strategy of achieving ultrahigh mechanical strength, toughness, and self-healing properties simultaneously in a hybrid dual crosslinked polyacrylic acid (PAAc) hydrogel. The hybrid PAAc hydrogel was fabricated in a one-pot reaction with two types of crosslinking points, i.e....
We have an ongoing interest in the design and control of helical conformation of water-soluble meta-linked poly(phenylene ethynylene)s (PPEs) and the further development of novel functional materials. Four cationic meta-linked PPEs (P1′-P4′) were synthesized to study the influence of differences in the backbone and side chain structure on their conformations. For P1′ and P4′ without side chains on...
Two novel water-soluble hyperbranched poly(p-phenyleneethynylene)s (HBP1′ and HBP2′) bearing different contents of oligo(ethylene oxide) (OEO) side chains with ammonium end groups were synthesized by the facile “A 2 + B 2 (or A 2 ′) + C 3 ” protocol based on Sonogashira polymerization. Their linear analog (LP2′) was also synthesized for comparative investigation. The...
Various methods were employed to study the thermal behaviors of a novel microbial polyhydroxyalkanoate (PHA) terpolyester, namely, poly(3-hydroxybutyrate-co-3-hydroxyvalerate-co-3-hydroxyhexanoate) (PHBVHHx) compared with poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx). PHBVHHx showed higher crystallization rate and degree of crystallinity. PHBVHHx exhibited also different multiple melting...
The pH-sensitive hollow poly(N,N′-methylenebisacrylamide-co-methacrylic acid) (P(MBAAm-co-MAA)) microspheres with movable magnetic/silica (Fe 3 O 4 /SiO 2 ) cores were prepared by the selective removal of poly(methacrylic acid) (PMAA) layer in ethanol/water from the corresponding Fe 3 O 4 /SiO 2 /PMAA/P(MBAAm-co-MAA) tetra-layer microspheres, which were...
A thermoplastic polyolefin elastomer-graft-polylactide (TPO–PLA) was prepared by grafting polylactide onto maleic anhydride-functionalized TPO (TPO–MAH) in the presence of 4-dimethylaminopyridine (DMAP). The characterization of the TPO–PLA copolymers was conducted by FT-IR and 1 H NMR. The effects of reaction temperature and concentration of DMAP on the reactivity of graft polymerization were...
A series of hyperbranched triazine-containing polyfluorenes were synthesized by an “A 2 +A′ 2 +B 3 ” approach based on Suzuki polycodensation. The polymers showed pure blue emission and the maximum emissions red-shifted in polar solvents and in solid film. By introducing triazine into polyfluorene, the electron injection and transport properties were improved and green emission...
An alternating copolymer was synthesized by Suzuki reaction from 4,4′-dibromo-p-quaterphenyl (PPP oligomer) and 9,9-dioctylfluorene-2,7-diboronic acid in good yield (84%). The copolymer is partially crystalline, readily soluble in organic solvents, presents high fluorescence quantum yield (85.6%) and high thermal stability. The copolymer absorption as well as the emission spectra are red shifted compared...
A series of novel hybrid organic–inorganic light-emitting materials, polyhedral oligomeric silsesquioxane-tethered poly(fluorenyleneethynylene)s, were successfully synthesized via Sonagashira coupling reaction. The chemical structures of these copolymers were determined by 1 H NMR and FT-IR spectra. The morphologies of these copolymers were studied in details using TEM and WAXD. The WAXD data...
The vapor of monomer, Si(Pc)(OH) 2 , is deposited onto the (100) face of NaCl single crystal which is heated at 350 o C under a dynamic vacuum of 10 -3 Pa. Epitaxial crystallization occurs on the substrate, and condensation polymerization takes place in situ at the same time. The resulting product is a kind of nanocrystalline film of [Si(Pc)O] n that is composed...
The toughness of PP/EPDM blends was measured over a wide range of temperature (25-132°C) and composition (0-26 wt% EPDM). It was found that increasing temperature and decreasing interparticle distance have equivalent effects on the brittle-tough transition of toughening PP with EPDM, and the shift factor increases with increasing temperature. A correlation was also found between temperature and...
Blends of nylon-6 and epoxidised ethylene propylene diene (eEPDM) rubber were prepared through reactive mixing. It is found that the toughness of nylon-6 can be much improved by this method, and that the particle size of eEPDM is much smaller than that of unexpoxidised EPDM (uEPDM) rubber in a nylon-6 matrix. This indicates that the epoxy group in eEPDM could react with a nylon-6 end group to form...
A super-tough polycarbonate (PC) blend was obtained by using epoxidized ethylene propylene diene (eEPDM) rubber as modifier. The notched Izod impact strength of PC/eEPDM (96/4) blend shows a great improvement, with a value about 25 times of that of pure PC. Finely and homogeneously dispersed rubber particles (0.2-0.8 μm) in the PC matrix indicated good adhesion between the eEPDM rubber phase and...
Irradiation can be applied to crosslink the dispersed elastomer phase to increase the modulus and decrease the voiding ability of the elastomer, which results in increasing critical brittle-tough transition elastomer content at constant temperature. The experimental results show that at 25°C the critical elastomer content of EPDM shifts to higher composition (shift of about 4 wt%) for PBT/EPDM blends...
In this paper, unepoxidized ethylene propylene diene rubber (uEPDM) was first epoxidized with formic acid and H 2 O 2 , and then the epoxidized ethylene propylene diene rubber (eEPDM) was melt-mixed with PBT resin in a Brabender-like apparatus. Toughening of PBT matrix was achieved by this method. The dispersion of rubber particles and phase structure of the blends were also observed...
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