Aihua He

• Qingdao University

Incrementing thermal conductivity in polymer composites through the incorporation of inorganic thermally conductive fillers is typically constrained by the requirement of high filler content. This necessity often complicates processing and adversely affects mechanical properties. This study presents the fabrication of a polystyrene (PS)/boron nitri...

In this paper, a series of novel trans ‐1, 4‐polyisoprene/isotactic polybutene (TPI/ i PB) in‐reactor blends were synthesized by isoprene and butene sequential two‐stage polymerization technology with spherical TiCl 4 /MgCl 2 type Ziegler‐Natta catalyst. The components, structures, and properties of the as‐obtained TPI/ i PB reactor blends were cha...

The thermo-oxidative aging of rubber products is inevitable during their use and leads to product failure and can even endanger safety. Oxygen is an important factor that cannot be ignored during the thermo-oxidative aging process. Thus, the gas barrier property of rubber products is of significant concern. In this work, a strategy of crystallizing...

Microwave-absorbing materials with heterostructure represent a major challenge and opportunity in enabling strong microwave absorption over a wide bandwidth. Here, novel hydrophilic multi-heterostructure composites (Mag@J/MWCNT) were fabricated by combining nanostructured Fe3O4 covered snowman-like Janus nanoparticles (Mag@J) with MWCNTs for enhanc...

The creep resistance of polymer determines the dimensional stability of product under stress. The isotactic polybutene-1 (iPB) with outstanding high-temperature creep resistance and stress-crack resistance is applied widely in the field of hot-water pipes. Although the chain information including weight-average molecular weight (Mw) and aggregate s...

To better understand the two synchronous processes of lamella orientation and crystal transition of iPB‐1 during stretching, the stretching‐induced changes in the crystal structure of iPB‐1 were investigated at different temperatures (room temperature, 65, and 85°C) and stretching speeds (5, 10, and 20 μm/s). It was discovered that the acceleration...

As the most popular rubber blends in rubber industry, the aging behaviors of NR/BR vulcanizates have been a major challenge in science and industry. Our previous work reported the substitution of trans-1,4-poly (isoprene-co-butadiene) (TBIR) for BR in filled NR/BR vulcanizates for improved thermo-oxidative resistance. However, the effect of microst...

Shear flow is important to understand the relationship between processing and properties of polymer products. In this work, the influences of shearing and high-molecular-weight polybutene-1 (HMwPB) on the evolution of oriented crystal's morphologies of isotactic polybutene-1 (PB) were investigated by shearing at a temperature slightly above the nom...

In order to construct the rubber nanocomposites with desired dual network structures, the trans-1,4-poly (butadiene-co-isoprene) copolymers (TBIR)/carbon black (CB) nanocomposites were prepared by in-situ polymerization in the presence of large amounts of CB using TiCl4-type Ziegler-Natta catalysts. It was found that the addition of CB had no obvio...

Polymer blending is one of the most economical and effective techniques for achieving products with high comprehensive performances. However, the immiscibility between polymers results in a weak interface, which is typically the position where material failure starts when an external force is applied. Therefore, understanding and controlling the in...

Multi-block stereoregular copolymer of styrene and isoprene was realized by stereospecific copolymerization with supported titanium Ziegler-Natta catalyst [TiCl4/MgCl2-Al(i-Bu)3] successfully. Effects of initial monomer ratio (Ip/St) on catalyst efficiency (CE) and composition and sequence structure of the as-obtained copolymers were studied. Appar...

The blends based on natural rubber (NR) and cis-1, 4-polybutadiene rubber (BR) are the most popular materials in rubber industry. As is well-known, the rubber blends suffer thermos-oxidative aging during the service life. However, the problems, such as immiscibility, discrepant aging behaviors, uneven distribution of fillers in different phase, res...

Blending isotactic polybutene-1 (PB) with isotactic polypropylene (PP) is a facial strategy to improve the mechanical properties and promote polymorphous transformation of PB. As the immiscible polymer pairs with strong crystallizability, the interactions between PP and PB in the melt state influence the subsequent processes like phase separation a...

External electron donors (ED) as one of the components in traditional Ziegler-Natta (Z-N) catalysts play important roles in determining the activity, stereoregularity of the active species for ɑ-olefin polymerization. Alkoxysilanes with different size and different electron-donating alkyl substituents were investigated to study the stereoregular po...

Electromagnetic (EM) shielding materials have attracted significant attention, owing to their widespread potential in preventing EM irradiation in electrical devices and human bodies. In this study, a hierarchical porous carbon nanotube (CNT) skeleton with electrical continuity is presented, which is rapidly fabricated via the facile microwave pyro...

Developing stretchable strain sensors with high stretchability as well as sensitivity via a scalable technique is still a challenge that remains to be addressed. Herein, high‐performance stretchable strain sensors based on Ag nanoparticles (NPs) sandwiched between two thermoplastic polyurethane (TPU) fibrous textiles are fabricated by combining 3D‐...

Developing high-performance “green” tire tread material with superior balanced integrated properties is of vital importance in view of environment, resource and energy consideration. In this work, effective and facile strategies concerning macromolecular functionalization and cross-linkable crystalline component incorporation have been proposed to...

Alkylaluminium is one of the components of the Ziegler-Natta catalysts, which plays a significant role in the active materials with different regions and stereoselectivity. The polymerization of isoprene with alkylaluminium in TiCl4/MgCl2 type Ziegler-Natta catalysts system is rarely studied by simulation. In this work, density functional theory (D...

Thin-film wearable strain sensors attract increasing attention due to their minimal invasiveness onto the human skin and potential use in health monitoring; however, the simultaneous achievement of high sensitivity and stretchability with such sensors is challenging, and mechanical compliance is rarely considered. Using a thin and hierarchical poro...

High isotactic polybutene-1 (HiPB) plays important roles in presenting outstanding resistance to creep and crack at high temperature. Therefore, rapid and accurate measurement of the HiPB is extremely important for both synthesis and application of polybutene-1 (PB). In this work, solvent extraction fractionation with diethyl ether (DE) and n-hexan...

The isoprene polymerization kinetics by using TiCl4/MgCl2 type Ziegler-Natta catalysts (TMC) with different titanium contents were studied for better understanding the possible active-specie structures of heterogeneous Ziegler-Natta (Z-N) catalysts for conjugated diene polymerizations. The catalytic features including the catalytic activity (CA), n...

The influences of alkylaluminium compounds including triethylaluminium (TEA), triisobutylaluminium (TIBA) and diethylaluminium chloride (DEAC) on the catalyst activity, isotacticity and weight-average molecular weight (Mw) of the products in butene-1 (Bt-1) polymerizations with MgCl2-supported TiCl4 Ziegler-Natta catalysts were investigated. The ca...

Most of natural water-soluble polymers are difficult to electrospin due to their specific chain conformation in aqueous solution, which limits their applications. This study investigated the effects of polyethylene oxide (PEO) on the electrospinning of hyaluronic acid (HA) in HA/PEO aqueous solutions. The rheological properties of HA/PEO aqueous so...

A series of isotactic polybutene-1/polypropylene (PB/PP) in-reactor alloys were prepared by Ziegler-Natta catalyst using sequential two-stage polymerization technology. Temperature rising elution fractionation (TREF) combining with DSC, GPC and ¹³C-NMR were used to analyze the compositional heterogeneity of the resulting PB/PP alloys. Fractions in...

In order to analyze the chain structure and sequence distribution of trans-1,4-poly(isoprene-co-butadiene) copolymers (TBIR) with different butadiene content, a preparative-temperature rising elution fractionation (P-TREF) technique was used to fractionate the TBIR into 10 to 12 fractions based on the elution temperature ranged from −40 °C to 70 °C...

Amphiphilic Janus nanosheets with reactive rubber brushes (PBd-silica-PI) were fabricated by using silica nanosheets as templates and attaching polyisoprene (PI) and polybutadiene (PBd) brushes onto opposite sides. The compatibility between the attached polymer brushes and the rubber matrix accounted for reduced phase domains, revealed as a biconti...

In this work, the effects of orientated crystal morphology of polypropylene (PP) induced by tensile stretching on the subsequent crystallization behavior of polybutene-1 (PB-1) in the incompatible PP/PB-1 (50/50) blends were studied. When the PP/PB-1 blends were stretched at a temperature above melting temperature (Tm) of PB-1 but below the Tm of P...

In melt recrystallization of trans-1,4-polyisoprene (TPI), polymorphism was examined via differential scanning calorimetry (DSC), polarized optical microscopy (POM), and wide-angle X-ray diffraction (WAXD). Two crystal modifications of TPI, namely β-TPI (metastable form) and α-TPI (thermodynamic stable form), exhibit difference in their ability to...

Toughening polypropylene (PP) with the good balance of toughness and stiffness was achieved via dynamic vulcanization technology by blending with trans-1,4-poly(isoprene-co-butadiene) rubber (TBIR), a novel copolymer containing trans-polyisoprene blocks with glass transition temperature (Tg) around −70 °C and melting temperature (Tm) around 25–45 °...

Higher performance tire tread stocks with lower rolling resistance, higher abrasion and fatigue resistance are urgent needs considering the environmental protection, resource saving and personal safety. In this paper, high trans-1,4-poly(butadiene-co-isoprene) copolymer rubbers (TBIR) consist of three main fractions containing trans-1,4-polyisopren...

An admixture of isotactic poly (1-butene) (iPB) with isotactic polypropylene (iPP) enhances the scope of consumer applications and the commercialization of iPB because of the reduced price. However, the properties of the mixtures are not superior to but are intermediate between those of the components. Achieving high performance iPB materials by bl...

Janus fillers represent a combination of inorganic thermally conductive silver nanoparticles and organic polystyrene brushes on one entity but different sides. They are of practical importance for polymer composites with high thermal conductivity because of the improved dispersion and reduced interfacial heat resistance. Moreover, benefiting from t...

Solution polymerized styrene-butadiene rubber (SSBR) is commonly used as rubber tread stock for high wet-skid resistance, but SSBR suffers from shortcomings including high rolling resistance, unsatisfied abrasion resistance and fatigue resistance, which triggers great research efforts in pursuing tread stock with balanced performances. Herein, a fa...

Filled natural rubber (NR)/cis-1, 4-polybutadiene rubber (BR) blends are commonly used as tire sidewall stocks. However, the incompatibility and mismatched curing rate between NR and BR and selective distribution of fillers in BR phase result in unsatisfied dynamical properties of NR/BR blends. Herein, we have proposed a facile approach to modulate...

High trans-1,4-poly(butadiene-co-isoprene) (TBIR) copolymers from the stereo-selective and chemo-selective copolymerization of butadiene (Bd) and isoprene (Ip) are reported with MgCl2 supported Ziegler-Natta catalyst (TiCl4/MgCl2–Al(i-Bu)3). Three major components in the copolymers, separated by stepwise isothermal crystallization fractionation, co...

The rheological behaviors of polypropylene (PP)/poly(1-butene) (PB) blends with homo-polypropylene (PP1) or impact polypropylene (PP2), a poly(propylene-co-ethylene) as the PP component were studied. With increasing of PB resin content for both PP/PB blends, the blends showed higher G'(ω), G''(ω) and η*(ω) at low frequencies but lower values at hig...

Because amorphous cis-1,4-polyisoprene(CPI) and crystalline trans-1,4-polyisoprene(TPI) are isomers, with similar refractive index, electron density and even glass transition temperatures, confirmation of miscibility is difficult by using most direct methods, such as phase contrast optical microscopy, small angle X-ray scattering (SAXS) and differe...

Janus particles are promising for self-assembly at the liquid/liquid interface due to coexistence of the Pickering effect and the different wettability of both sides. In this study, we synthesize a Janus nanosheet and evaluate its ability to trap nonequilibrium morphology by interfacial self-assembly. The Janus nanosheet was synthesized by selectiv...

Solution crystallization of TPI is relatively less concerned, though the crystallization kinetics from solution is profoundly related to the advance in fraction purification and the precipitation polymerization of TPI. In this work, isothermal crystallization of TPI from its solutions with varied concentrations and solvents at temperatures ranged f...

Zwitterionic graft copolymers, hydroxypropyl cellulose graft poly(2-(methacryloyloxy) ethyl phosphorylcholine) (HPC-g-PMPC) with well-defined architecture were synthesized by atom transfer radical polymerization (ATRP). The self-assembly behaviors and thermal sensitivity of HPC-g-PMPC copolymers and their correlations with graft density and side ch...

In this work, the combined effects of polydispersity and viscosity on microstructure that evolves with domain coarsening and crystallization are investigated in the blends of amorphous solution polymerized styrene-butadiene rubber (SSBR) and crystalline trans-1,4-polyisoprene (TPI). We find that the bicontinuous patterns in SSBR/TPI undergo a compl...

Cold flow is a well-known characteristic and also an unresolved drawback for uncured rubber materials. In this paper, a simple approach of retarding the cold flow of cis-1,4-polybutadine (BR) elastomer is reported by controlling the phase separation and crystallization that occurred in immiscible BR/trans-1,4-polyisoprene(TPI) blends. The BR/TPI bl...

A structure study of epoxidized trans-1,4-polyisoprene (ETPI) synthesized by heterogeneous method is carried out using ¹³C-NMR. In this paper, we present a new analytical method for assigning overlapping ¹³C-NMR signals of ETPI in terms of the triad of trans-1,4-isoprene and epoxidized units. The monomer unit sequence distributions in epoxidized fr...

The rheological properties of polybutene-1 with different molecular weight (M w) and polydispersity index (PDI) were studied by means of rubber-processing analyzer (RPA). The studies included strain sweeps, frequency sweeps, temperature sweeps, and stress relaxation tests after a sudden shear displacement. It is observed that the linear viscoelasti...

The aging property of poly(1-butene) in which different antioxidant system were added was characterized by its physical and mechanical properties before and after aging for 300 h in a hot air aging box. In addition, the oxidation induction time (OIT) of all designed samples was tested. The result demonstrated that the primary antioxidant pentaeryth...

In this paper, Janus hybrid particles with rubber brushes have been first fabricated by successively grafting polybutadiene chains onto polydivinylbenzene (PDVB) side and polyisoprene chains onto SiO2 side in the case of SiO2@PDVB Janus particles as the template. The weight grafting ratios (Gr) of polybutadiene (PBd) and polyisoprene (PI) brushes w...

In this study, the correlations between composition and properties of epoxidized trans-1,4-polyisoprene (ETPI) with the same epoxy degree have been established. It can be seen from the morphology obtained by SEM, there was a clear distinction of phase separation between the raw ETPI samples with different compositions. Also, the mechanical properti...

Zwitterionic polymers have both anion and cation groups in one molecular chain. They include several types of polymers e. g. phosphorylcholine-, sulphobetaine-, carboxyl betaine-, and mixed-charge polymer, according to the different macromolecular structures. They can be cation or anion polyelectrolyte by adjusting the pH values in aqueous solution...

In this paper, a crystalline/crystalline polyolefin alloy - isotactic polypropylene/ isotactic polybutene-1 (iPP/iPB) in-reactor alloys with spherical particle morphology, were synthesized by sequential two-stage polymerization using spherical MgCl2-supported Ziegler-Natta catalyst. The achieved iPP/iPB alloys were mainly composed by isotactic poly...

Morphology, curing characteristics, mechanical and dynamic properties of vulcanization of epoxidized trans-polyisoprene (ETPI) with different epoxy content were investigated. From scanning electron microscopy micrographs, it is observed that ETPI vulcanizates were a two-phase system. DSC shows that the residual crystallization reduced with increasi...

A special external component (triphenyl phosphate), which was introduced into the iron(III) complexes system was studied. Some of the greatly affected parameters include the catalytic activity, stereospecificity (obvious increases of 3,4 content), polymer molecular weight, and molecular weight distribution.

In situ FTIR testing demonstrated that crystallization of novel poly(1-butene)/poly(propylene-co-butene) in-reactor alloys from melt shows thermodynamic stable Form I directly rather than general reported unstable crystal Form II. In order to make clear this phenomenon, the microstructure and monomer sequence distribution of the as-obtained poly(1-...

The aim of this study is to analyze the structure and morphology of epoxidized trans-1,4-polyisoprene (ETPI) obtained by water phase suspension epoxidation. With this objective, the range of epoxy group content of ETPI from 0 to 25 mol% was used. The Fourier transform infrared spectroscopy indicated that the dissoluble parts separated by ethyl acet...

Trans-polydiene rubber family as high-performance tire stock possessed excellent dynamic properties, including excellent anti fatigue, low rolling resistance, low heat buildup, good green strength, and low abrasion loss. Here, Reactor Granule Technology (RGT) was introduced into the field of synthetic rubber for the first time to produce trans-1.4-...

The discovery of Ziegler − Natta catalysts has been one of the greatest developments in technology for the synthesis of stereoregular polymers in both academy and industry since the 1950s. In particular, the development of the fourth generation Ziegler − Natta catalyst with MgCl2 as support brings a revolutionary improvement to the properties of ma...

Polymerization behaviors of isoprene under different polymerization conditions with 2-(1-methyl-2-benzimidazolyl)-6-(1-(arylimino)ethyl) pyridine cobalt(II) dichloride and ethylaluminum sesquichloride or diethylaluminum chloride catalyst system were evaluated. The effects of temperature, solvents, [Al]/[Co] molar ratio, and the structure of cocatal...

Polyisoprene (PI) with a high content of cis-1,4 (up to 95%) or cis-1,4/3,4 binary structures was synthesized using a cobalt system in toluene. The cobalt system, which exhibited high activities (up to 3.50 × 106 g PI (mol Co)−1 h−1), contained a series of 2-(benzimidazolyl)-6-(1-(arylimino)ethyl)pyridine cobalt(II) dichlorides activated with ethyl...

Selectively epoxidized trans-1,4-polyisoprene (SETPI) and randomly epoxidized trans-1,4-polyisoprene (RETPI) were fabricated successfully through modified surface water-phase suspension epoxidation and solution random epoxidation, respectively. The effects of fabricated method and epoxy degree of ETPI on the glass transition temperature (T g), dyna...

Crystallization and polymorphic transformation of poly(1-butene)/(1-butene-co-propylene) in-reactor alloy (iPB/B-co-P) with different chain structure prepared by two stage sequential polymerization was investigated by DSC, FTIR and POM. As can be concluded from DSC results, the crystal form II to I transformation rate is enhanced with the increase...

In this work, electrospun poly(lactide-co-glycolide) (PLGA) fibrous membranes were functionalized with radionuclides by surface modification. After the introduction of chitosan and bifunctional ligands (DTPA) on soft hydrolyzed PLGA nanofibrous membranes, more than 80% of the radionuclides (90Y) in aqueous solutions were attached as labels to the t...

A series of isotactic polybutene-1/polypropylene (PB/PP) alloys with spherical morphology were prepared by MgCl2-supported Ziegler-Natta catalyst with sequential two-stage polymerization technology. The first formed PP particles were used as micro-reactors to initiate the bulk precipitation polymerization of butene-1 further. The porous PP particle...

The isotactic poly(1-butene)/ poly(1-butene-co-propylene) in-reactor alloy was prepared by heterogeneous titanium catalyst system. The differences of crystal phase transformation time, phase transformation rate and phase transformation time between Form I and Form II at a given transformation degree at 25 °C by fourier transform infrared spectrosco...

MgCl2/TiCl4/diether is a fifth-generation Ziegler–Natta catalyst for the commercial polymerization of propylene. The outstanding features of this catalyst are the high activity and high isotacticity for propylene polymerization without using an external electron donor. In this study, we explored the copolymerization of propylene and 1-octene with M...

Polypropylene/clay nanocomposites (PPCNs) were prepared via an in situ polymerization method with a Ziegler–Natta/clay compound catalyst in which the MgCl2/TiCl4 catalyst was embedded in the clay galleries. The wide-angle X-ray diffraction and transmission electron microscopy results showed that the clay particles were highly exfoliated in the poly...

The effect of molecular weight on the polymorphic transformation of isotactic poly(1-butene)(iPB) under room temperature had been investigated by fourier transform infrared spectroscopy(FT-IR). The phase transformation time, phase transformation rate and phase transformation time difference between phase I and phase II at a given transformation deg...

Electrospun nanofibrous membrane is an approved drug carrier. However, the radionuclide carrier used an electrospun membrane is rare. In this study, Poly(lactide-co-glycolide)(PLGA) nanofibrous nonwovens were prepared through electrospinning technology, and then surface modification of the nonwoven was performed to stably conjugate the radioisotope...

Four kinds of imidazolium surfactants with high thermal stability were designed and synthesized accordingly. The structures of these surfactants were characterized by 1H NMR spectra. The TGA results indicated that the thermal stabilities of these surfactants with saturated alkyl groups were relatively high and the initial decomposition temperatures...

The phase transition from α-tricalcium phosphate (α-TCP) into β-tricalcium phosphate (β-TCP) in tricalcium phosphate/hydroxyapatite (TCP/HA) composites was investigated by X-ray diffraction, differential scanning calorimetry, thermogravimetry and scanning electron microscopy in this study. The current experimental results indicated that the calcini...

Highly exfoliated isotactic-polypropylene/alkyl-imidazolium modified montmorillonite (PP/IMMT) nanocomposites have been prepared via in situ intercalative polymerization. TEM and XRD results indicated that the obtained composites were highly exfoliated PP/IMMT nanocomposites and the average thickness of IMMT in PP matrix was less than 10 nm, and th...

Although sodium alginate (SA) could not be electrospun from its aqueous solution, SA-based electrospun nanofibers can be fabricated with the help of polyethylene oxide (PEO). In this study, the influence of PEO on the electrospinnability of SA aqueous solution was investigated and the roles of chain entanglements and conformations of the blend syst...

Hyaluronic acid (HA) ultra-thin fibrous membranes by electrospinning technology had been fabricated successfully by our group. However, these HA fibrous membranes dissolve and decompose rapidly in water. In this study, chemical crosslinking of HA and HA based ultra-thin fibrous membranes was studied in detail. It was found that the chemically cross...

For materials containing fluorine, it has been generally accepted that fluorinated segments or end groups tend to aggregate in the outer surface because of the low surface energy, which endows the fluorinated materials with special surface properties such as self-cleaning, superhydrophobicity, and so forth. However, for the electrospun fibrous memb...

Fibers prepared by melt spinning process from the PP (polypropylene)/organoclay nanocomposite were characterized in details with the aid of SEM, FTIR, XRD, DSC, and mechanical measurements. The results suggested that the lower content of organoclay (0.1%) added to the PP matrix increased the crystallinity and mechanical property (tensile strength)...

Improving and understanding the electrospinnability of native cellulose in room temperature ionic liquids (RTIL) have been a hot issue in recent years. In this study, the electrospinning of cellulose in a highly efficient RTIL of 1-allyl-3-methylimidazolium chloride (AMIMCl) was investigated. The introduction of co-solvent dimethyl sulfoxide (DMSO)...

As a natural biopolymer, sodium alginate (SA) has been widely used in the biomedical field in the form of powder, liquid, gel, and compact solid, but not in the form of nanofiber. Electrospinning is an effective method to fabricate nanofibers. However, electrospinning of SA from its aqueous solution is still a challenge. In this study, an effort ha...

Electrospinning is an effective and simple method to fabricate polymer fibers in the range of nano scale. However, electrospinning of natural polymers is a challenge. The key reason for this problem is that natural polymers have very different chain conformation and hydrodynamic responses in solution, especially in aqueous solution, when compared w...

The crystalline morphology and the liquid−liquid phase separation (LLPS) of an isotactic polypropylene/poly(ethylene-co-octene) (iPP/PEOc) polymer alloy prepared on a single multicatalyst reactor granule were studied by polarized optical microscope, phase contrast optical microscope, and scanning electron microscopy (SEM). We found that the LLPS pr...

Highly exfoliated poly(propylene) (PP)/clay nanocomposites with obvious improvements in both the tensile strength and toughness have been prepared by a novel TiCl 4 /MgCl 2 /imidazolium‐modified montmorillonite (IOHMMT) compound catalysts. Through this approach, in situ propylene polymerization can actually take place between the silicate layers an...

Polymorphism control of PVDF has been realized through electrospinning. PVDF fibrous membranes with fiber diameter in the range of 100 nm to several micrometers were produced by electrospinning and the crystal phase of electrospun PVDF fibers can be adjusted at the same time. Through the control of electrospinning parameters such as the solvent, el...

Polystyrene (PS) surfaces with various morphologies have been produced by electrospinning or electrospraying, such as beads with different sizes and shapes, bead-on-string structures with different aspect ratios of the beads and fibers with different diameters and shapes. Both the solution properties and the electrospinning conditions affected the...

Alkyltriphenylphosphonium-modified montmorillonite(PMMT) was used to prepare TiCl4/MgCl2/PMMT compound catalyst and exfoliated i-PP/PMMT nanocomposites were prepared by in situ intercalative polymerization of propylene with TiCl4/MgCl2/PMMT catalyst. The catalytic efficiency of the above catalyst under optimum polymerization condition could reach a...

It was found that the processability of HA solution with high viscosity had been improved greatly by using a DMF-water solvent mixture or/and by adding gelatin(GE) into the HA solution. Nano-fibrous membranes with different average fiber diameters and different HA/GE compositions could be obtained. Measurements on viscosity indicated that the HA so...

The phase behavior of poly(ethylene‐ co ‐styrene) (PES) and poly(ethylene‐ co ‐butene) (PEB) blends has been studied. A closed‐loop phase diagram was clearly observed in this weakly interacting system as the styrene content in the PES decreased to about 1 mol‐%. At higher styrene contents, the phase loop starts to interplay with the crystallization...

Poly(propylene)/monoalkylimidazolium‐modified montmorillonite (PP/IMMT) nanocomposites were prepared by in situ intercalative polymerization of propylene with TiCl 4 /MgCl 2 /MMT catalyst. The PP synthesized possessed high isotacticity and molecular weight. Both wide‐angle X‐ray diffraction (XRD) and transmission electron microscopy (TEM) examinati...