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To face the increasing demands of self-healing hydrogels with biocompatibility and mild condition degradability, one brand new type of P(NIPAM-FPA-DMA) copolymers were prepared in this study. The copolymers were cross-linked by dihydrazide compound to form acylhydrazone containing self-healable hydrogels without additional catalysis. Herein, the chemical structure, as well as microscopic morphologies,...
Generally, thermo-responsive hydrogels are prepared from thermo-responsive polymers like PNIPAM and its copolymers thereof. In this research, self-healable hydrogels with thermo-responsiveness and regulated cloud points (CPs) were prepared from water soluble P(N,N-dimethylacrylamide98-stat-diacetone acrylamide44) P(DMA98-stat-DAA44) through crosslinking induced thermo-responsiveness (CIT) mechanism...
The adsorbed species on nanofillers is one of the most important factors that may influence the performance of polymer nanocomposites. Herein, we performed a systematic investigation of the effects of the residual surfactant introduced by a synthetic method on the glass transition temperature (Tg) of polystyrene/gold nanoparticle nanocomposites. The surfactant was found to cause an obvious decrease...
Aiming to effectively codeliver chemotherapeutic drugs (DOX) and siRNA (BCL-2 siRNA) into tumor cells, well-defined triblock copolymers composed of hydrophilic and hydrophobic blocks were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. The poly(ethylene glycol) (PEG) macroRAFT agent and two pH-sensitive monomers (2-(diethylamino)ethyl methacrylate, DEA and 2-(dimethylamino)ethyl...
Hydrolytic degradation ability is an intriguing characteristic of poly(l-lactide) (PLLA) and it has been intensively investigated recently. However, the microstructure evolution of PLLA during the early stage of the hydrolytic degradation process is neglected. In this work, amorphous PLLA was hydrolyzed in alkaline media at temperatures from 40 to 60 °C. The variations of weight loss and molecular...
Although previous work has already shown that the presence of functionalized multiwalled carbon nanotubes (FMWCNTs) induced the great improvement of fracture toughness of an immiscible polymer blend, there is not exact evidence to show that the improvement of fracture toughness is only attributed to the improvement of interfacial adhesion resulting from the selectively distributed FMWCNTs at the interface...
Functionalized multiwalled carbon nanotubes (f-MWCNTs) have been introduced into immiscible polypropylene/ethylene-co-vinyl acetate (PP/EVA) blends. Two different compositions, one (PP/EVA=80/20) exhibits the typical sea-island morphology and the other (PP/EVA=60/40) exhibits the cocontinuous morphology, have been prepared with different contents of f-MWCNTs. The impact measurement shows that f-MWCNTs...
Imidazolium salts, most of which are room temperature ionic liquids (ILs), have been introduced as effective and tunable cocatalysts in the copolymerization of CO 2 with epoxides catalyzed by (salen)Cr III Cl complex for the first time. Effects of imidazolium salts with different alkyl chains as well as with different anions on the copolymerization were investigated. The results showed...
Shish structure and its relaxation dependence of re-crystallization of isotactic polypropylene (iPP) from an oriented melt, caused by melting of shish kebab in original samples (indicated by 2D SAXS and 2D-wide-angle X-ray scattering experiments (2D WAXS) measurements), has been investigated by differential scanning calorimetry (DSC) and optical microscopy (OM). Shish was obtained by dynamic packing...
The interfacial polymerization of aniline at aqueous/IL has been conducted. The product was characterized by transmission electron microscope (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV-vis spectroscopy, thermal gravimetric analysis (GTA), and electrical conductivity measurement. In this route, both solvents used are environmentally benign and polyaniline (PANI)...
pH sensitive membrane was prepared by grafting acrylic acid (AA) on the porous polypropylene (PP) membrane using supercritical (SC) CO 2 as a solvent. The monomer (AA) and the initiator (benzyl peroxide, BPO) were impregnated into the PP substrate with the aid of SC CO 2 , and were grafted onto the microporous PP substrate. The grafted membranes were characterized by Fourier transform...
In order to better understand the effect of shear stress on the crystal morphology and orientation of polyolefins, dynamic packing injection molding was used to prepare oriented pure polypropylene (PP) and its blends with linear low density polyethylene (LLDPE). The obtained samples were characterized via 2d-SAXS, 2d-WAXD and AFM. Macroscopically, shear induced morphology with surface skin, central...
The formation of phase morphology of injection molded HDPE/EVA blends, under the effect of shear stress, has been investigated in detail. The shear stress was induced by dynamic packing injection molding, by which a specimen is forced to move repeatedly in the model by two pistons that move reversibly with the same frequency during cooling. Two kinds of EVA with VA content 16wt% (16EVA) and 33wt%...
In order to further understand the brittle–ductile (B–D) transition in PP/EPDM blends, a shear stress field achieved via dynamic packing injection molding was used to control the rubber particles as elongated and orientated in the PP matrix. The impact strength of the blends was measured in three fracture directions, namely, along the shear flow direction, perpendicular to and oblique (45°) with the...
A poly(bisphenol A octane ether) (BA-C8) was synthesized. The isothermal spherulitic growth process was studied in situ using atomic force microscopy (AFM) at room temperature. For spherulites formed by homogeneous nucleation, the growth process includes the birth of a primary nucleus, the development of a founding lamella and the growth of the founding lamella into a spherulite. An embryo below a...
As a part of long-term project aimed at super polyolefin blends, in this work, we report the mechanical reinforcement and phase morphology of the immiscible blends of polypropylene (PP) and polystyrene (PS) achieved by dynamic packing injection molding (DPIM). The shear stress (achieved by DPIM) and interfacial interaction (obtained by using styrene-butadiene-styrene (SBS) as a compatibilizer) have...
In this work, chemical structures and molecular parameters of grafted materials of PP-g-MAH prepared by melt reactive extrusion were studied by using electrospray ionization-mass spectrometer and gel permeation chromatography. It was found that the initial radicals, due to homolitic scission of dicumyl peroxide could be combined with maleic anhydride (MAH) monomers as well as polypropylene (PP) molecular...
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