Kinds Of Polymeric Materials Research Articles

Study on the application of embolization materials of polyvinyl alcohol particles

The application, advantages and disadvantages of PVA particle embolization materials were analyzed retrospectively, and the correlation between the application field and the choice of embolization materials was discussed, which provided a reference for clinical treatment. Relevant literatures in PubMed and Web of Science databases were searched, and the literature on clinical application and experimental research of embolic materials was systematically evaluated. The embolization mechanism, advantages and disadvantages, and clinical application of PVA particle embolization materials were discussed. Polyvinyl alcohol particles are such kind of polymer material that insoluble in water, high expansion coefficient, mechanical embolization of blood vessels, no sensitization reaction, no systemic acute toxicity, no intradermal stimulation reaction, safe and effective use. The adhesive liquid embolism material has no vascular toxicity and has been widely used. The application and upgrading of thrombolytic surface materials can significantly improve the blood compatibility of the materials. All kinds of embolic materials have their own advantages and disadvantages, and none of them can be suitable for all diseases. Therefore, it is very important to choose suitable embolic materials for safe and effective treatment.

Study about Mechanical Property and Machinability of Polyimide.

Polyimide (PI) is a kind of polymer material with properties of high heat-resistance and good mechanical strength. As a special engineering material, it has been widely used in the fields of aviation, nanotechnology, etc. PI has been regarded as one of the most promising engineering plastics in the future. Therefore, further research must be made on its mechanical properties and machinability of the PI, especially in ultra-precision machining. In this paper, both of the mechanical properties and machinability have been studied respectively. Through the nanoindentation experiment, the nanoindentation hardness and elastic modulus of PI are analyzed. Also, the single point diamond turning (SPDT) experiment is conducted to show that the form accuracy and surface roughness of PI surface can reach a submicron degree in peak-to-valley (PV) and a nanometer scale in surface roughness (Ra) respectively. The results demonstrate that the PI possesses good mechanical properties and machinability.

The synthesis of a smart streptavidin-functionalized poly(N-isopropylacrylamide) composite and its application in the separation and detection of virus nucleic acid

A new kind of polymeric material (PNIPAAm-co-SA) was prepared by conjugating a thermosensitive polymer, Poly (N-isopropylacrylamide) (PNIPAAm) with streptavidin (SA). This smart prepared composite displayed a controllable conformation change between an expanded and a collapsed form, below or above its lower critical solution temperature (LCST). Differential scanning calorimetry (DSC) analysis demonstrated that the PNIPAAm-co-SA bioconjugate showed the same LCST as the original synthetic polymer, PNIPAAm, which was also 32°C. Based on the specific interaction between SA and biotin, a higher capture efficiency of PNIPAAm-co-SA, which was almost 100% in PBS buffer solution and above 70% in serum was obtained, respectively. And the high affinity between PNIPAAm-co-SA and biotin was still maintained after three heating cycles. Subsequently, the variola virus (small pox, VV) oligonucleotide sequence was chosen as a model to demonstrate the sensitivity of the biosensor which was fabricated based on PNIPAAm-co-SA. The biosensor exhibited the ability to separate and enrich targets from complicated system with its phase transition ability, and high sensitivity toward VV-targets were achieved. Moreover, other types of targets such as proteins and cells, could be detected by changing the biotin-captures, which indicated the broad applicability of biosensors based on this smart polymer material.

Design of broadband near-infrared reflector using polymer multilayer heterostructure with low-refractive-index contrast

In the paper, to achieve total reflection in the short-wavelength near-infrared (NIR) region (780–1100 nm), a broadband NIR reflector using polymer multilayer heterostructure composed of several quarter-wave stacks was proposed. The reflector used two kinds of polymer materials: PMMA and PET with low-refractive-index contrast. Taking the solar power density as the target and the Bragg wavelength of each quarter-wave stack as the variable, a searching method based on arithmetic progression was applied to find the optimal results for broadband NIR reflection. The simulation results show that the broadband NIR reflector can obtain higher total reflectivity with the increase of the number of quarter-wave stacks, and 99.06% total reflectivity in the short-wavelength NIR region can be achieved by the polymer multilayer heterostructure with six quarter-wave stacks. The proposed polymer multilayer heterostructure can be fabricated by the micro–nanomultilayer co-extrusion technology based on torsion lamination, and could be applied in agriculture as NIR-blocking films.

Preparation and Thermal Properties of Silicon-containing Polyimide Composite Films

Aromatic polyimide is a kind of polymer material with high temperature resistance, low temperature resistance, radiation resistance, excellent chemical stability, excellent electrical properties and good mechanical strength. It has been widely used in aerospace, electrical and electronic fields. At present, the synthesis, properties and application of polyimide containing silicon is one of the hot spots in the research field of polyimide. The processing property of polyimide can be greatly improved by introducing silicon group or polysiloxane segment into the main chain structure. And it has been given a good solubility, permeability, impact resistance, UV resistance and anti-degradation in oxygen rich environment. The introduction of siloxane chain segments or silicon containing groups in polyimide framework can enhance the adhesion between polyimide and inorganic materials, including the adhesion of metal materials and other substrates. A variety of polyimide hybrid materials can be prepared by the excellent bonding properties. A series of polyimide / silicon containing polyimide / BaTiO3 nanocomposite films were prepared and their structures and properties were studied in this paper. In addition, the preparation, structure and properties of polyimide / mesoporous silica composite films were studied. Silicon containing polyimide/silane mesoporous silica composite films have low infrared emissivity compared with bulk polyimide. Under the same content of mesoporous silica, the composite films prepared by copolymerization have lower infrared emissivity. Moreover, the infrared emissivity decreases with the increase of the content of silica. In short, silicon containing polyimides and their composite films with excellent performance differ from other traditional polyimides, and it has broad application prospects in the technological field of aerospace, electrical and electronic, gas separation, absorbing material preparation.

Design and properties of high-performance polyamide 6/fluoroelastomer blends by electron-induced reactive processing

In recent years, electron-induced reactive processing (EIReP) has emerged as a state-of-the-art technology to modify and develop several kinds of polymeric materials. EIReP uses the spatial and temporal tuneable energy input by high energy electrons during melt mixing process in order to precisely control the desired chemical reactions and processability. Motivated by the successful development of high performance polyolefin based compounds by EIReP, we report herein for the first time the successful preparation of high-performance polyamide 6/fluoroelastomer (50/50, w/w) blends. Relationships between EIReP process parameters (non-reactive mixing time, dose per revolution, electron energy), morphology and properties of blends were established. The blends were prepared using a range of absorbed dose (12.5, 17.5 and 25kGy) while keeping constant values of electron energy (1.5MeV), dose per revolution (17.2kGy/rpm), temperature (230°C) and rotor speed (60rpm). The EIReP-modified blends exhibited excellent mechanical properties and outstanding oil swelling resistance along with good thermal stability. For example, volume swell of the blends was only 5–8% in IRM oil at 150°C for 72h, which was found to be the lowest amongst this type of rubber-plastic blends reported. The improved properties of these blends were explained with the help of interfacial tension between the phase components and electron-induced long-chain branching.

Study on Factor of the Quenching Performance on the Polymer Material Characteristics of an Air Circuit Breaker

Usage of polymer materials in a quenching chamber is one of the most effective methods of improving performance of an air circuit breaker [1, 2]. During a high current interruption in the air circuit breaker, an arc discharge touches the insulator, and ablation gasses are emitted [3]. It is considered that the quenching performance and an arc characteristic are affected by this ablation gasses. In order to clarify the quenching performance of each polymer material, we are conducting the experiments. With these experiments, the relationships of the ablation gasses among the number of arcing cycles, arcing peak voltage, arcing conductances, and the pressure rise will be discussed with four kinds of polymer materials.

Rational design of diarylethylene‐based polymeric semiconductors for high‐performance organic field‐effect transistors

ABSTRACTConstructing planar, rigid, and high electronically delocalized π‐conjugated molecular system is the most basic requirements of obtaining high‐performance polymeric semiconductors for organic field‐effect transistors (OFETs). In this regard, diarylethylene (DAE)‐based polymers show great potential because many substantive progresses related to polymer field‐effect transistors had been achieved from the kind of polymer materials in recent years. In the brief review, series of DAE‐based polymer are highlighted, based on which several design strategies have been summarized by the way of comparative research method. These strategies have important guiding significance not only for further developing new DAE‐based and other polymeric semiconductors for OFETs but also for developing specific polymeric semiconductors for other organic electronics, such as organic photovoltaics and organic light‐emitting diodes. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 585–603

Influence of Finishing Operations and Melt Flow Index on Surface Quality of Injection Molded Parts

In the production of polymer parts, great emphasis is placed on the quality of polymer product in terms of dimensional accuracy and optimally surface quality. Achievement of high surface quality of injection molded products correlate to the high surface quality of core or cavity in injection molds. This surface is copied during injection of polymer material. The kind of polymer material and its rheological properties can strongly influence this surface copying. Production of cores and cavities takes in the manufacturing process a considerable part of time, where some finishing technologies are more economically and time consuming than other processes. Thus, it is necessary to choose an appropriate finishing operations considering cost of injection mold, which is reflected in future price of polymer product. This paper experimentally examines the influence of the surface quality of mold cavities and rheological properties of polymer on the surface quality of injection molded product.

Formation of microporous polymeric membranes via thermally induced phase separation: A review

A review of recent research related to microporous polymeric membranes formed via thermally induced phase separation (TIPS) and the morphologies of these membranes is presented. A summary of polymers and suitable diluents that can be used to prepare these microporous membranes via TIPS are summarized. The effects of different kinds of polymer materials, diluent types, cooling conditions, extractants and additive agents on the morphology and performance of TIPS membranes are also discussed. Finally new developments in TIPS technology are summarized.

Viscous Characteristics of ETFE Film Sheet under Equal Biaxial Tensions

ETFE membrane film structures are often realized in construction. Because ETFE film is a kind of polymer materials, it shows both elasto-plastic and visco-elastic characteristics. Using FEM and experimental results of ETFE film, the authors developed the constitutive equation.First to investigate the elasto-plastic characteristics of ETFE, a biaxial tensile test was carried out. The elasto-plastic characteristics are formulated adopting the von Mises criterion under biaxial stresses. FEM analysis of the test of rectangular ETFE cushion under pressure showed the validity in presenting ETFE behaviour based on the proposed constitutive equation.Then to investigate the viscoelastic properties, an incremental formula of the constitutive equation was extended and introduced to FEM analysis. The test showed that uniaxial creep properties can be presented using the proposed constitutive equation.Furthermore, to present biaxial creep properties, the incremental form of the constitutive equation was extended and the confirmation was given for its validityIn this paper, also to investigate temperature dependency of the elasto-plastic characteristic, the following points are focused on:1.Under multiple temperature conditions, uniaxial and biaxial tensile tests as well as creep testes are carried out.2.To include these properties, an incremental form of the constitutive equation is presented.3.Confirmation of the validity of the proposed constitutive equation is given.

Structural origin of stress and shape recovery in shape memory starch

As other kinds of polymer materials, amorphous starch obtained by extrusion exhibits shape memory properties when submitted to a specific type of thermomechanical treatment, called Shape Memory Creation Procedure (SMCP). Depending on the draw temperature used in SMCP, X-ray diffraction shows that the amorphous structure of starch is modified, with increasing anisotropy for low temperatures. Concurrently, the draw temperature affects both shape and stress recovery, with a correlation between the maximum stress recovered and the level of anisotropy induced. Besides, the maximum of stress recovery appeared systematically below or at the glass transition temperature, while shape recovery occurred mainly above the glass transition temperature. These results are discussed in terms of molecular scale and mobility.

Comparison study of graphene based conductive nanocomposites using poly(methyl methacrylate) and polypyrrole as matrix materials

Graphene was used as the filler to mix with two kinds of polymer materials, poly(methyl methacrylate) (PMMA) and polypyrrole (PPy). PMMA is an insulator and PPy is an intrinsic semiconducting/conducting polymer. Graphene/PMMA nanocomposite (GrPMMA) was produced by solution blending and spin-coating deposition, and graphene/PPy nanocomposite (GrPPy) was produced by in situ polymerization and doctor-blade coating. The X-ray diffraction and Raman spectroscopy were used to characterize the structures of GrPMMA and GrPPy. The electrical conductivity was studied as a function of graphene concentration for both GrPMMA and GrPPy. The electrical conductivity of PMMA was improved drastically after adding graphene, and the electrical conductivity of GrPMMA increases as the graphene concentration increases. However, the electrical conductivity of PPy decreases after adding graphene, and the electrical conductivity of GrPPy decreases as the graphene concentration increases. The difference in change in electrical conductivity of PMMA and PPy after addition of graphene may be due to the different electron transport mechanisms of those two nanocomposite materials.

Status assessment of polymeric materials in mineral oil under electro-thermal aging by frequency-domain dielectric spectroscopy

Transformer development is limited to smaller sizes and larger capacities due to two major shortcomings: first, the solid insulation that is used in an oil-immersed transformer, which is generally cellulosic paper, cannot resist high temperatures, and second, the significant difference in the dielectric constants between the cellulose paper and the transformer oil will lead to an uneven electric field. In light of this situation, in combination with the requirements of oil-immersed transformers for the dielectric, physicochemical, and mechanical properties of solid insulations, in this study two kinds of polymeric materials are chosen as the research objects - Polycarbonate (PC) and Polyester (PET) - that can resist high temperature, and then, a comparative analysis is made with cellulose paper. They are put in the transformer oil for electro-thermal aging for 300 days at 90, 110, and 130°C, respectively. The variation characteristics of permittivity and the dielectric dissipation factor with frequency were examined in stages (30 days, 140 days, 180 days, 250 days, and 300 days). This paper studies the characteristics of polymer materials so as to analyze whether they can be used in an oil-immersed transformer by considering the materials’ physical properties, electron microscope scanning (SEM), and degree of polymerization (DP) at different stages during aging. This valuable exploratory work has never been studied before. If these two new materials can be applied, it will be of great significance to the innovation of the insulation structure of a power transformer.

Nanometer scale patterning of GaN using nanoimprint lithography and Inductively Coupled Plasma etching

In this paper results on GaN patterning using nanoimprint technology are presented. Direct method of stamp fabrication based on FIB etching was used. Stamp with critical dimensions of 50nm was achieved. Two kinds of polymer materials were used for master stamp replication. Influence of etching parameters using chlorine based plasma on GaN etch rate and surface roughness was discussed. Triple mask consisting of TU2 resist, Cr and SiO2 used for NIL-generated pattern transfer into GaN allowed successful patterning.

Enhanced fluorescence from CdSe/ZnS quantum dot nanophosphors embedded in a one-dimensional photonic crystal backbone structure.

A nano-engineered phosphor structure that produces enhanced fluorescence is reported. Two kinds of polymer materials with different refractive indices are spin-coated alternately to realize a one-dimensional (1D) photonic crystal (PC) phosphor platform, in which CdSe/ZnS core-shell quantum dots (QDs) were embedded as a fluorescence agent. The 1D PC phosphor structure is designed to match the pump photon energy with one of the photonic band-edges (PBEs), where the photon group velocity becomes zero, and thus the interaction between pump photons and fluorescent centres strengthened. A reference phosphor structure is also designed and fabricated; however, it has no PBE and exhibited bulk-like photonic properties. The fluorescence intensity from the 1D PC phosphors is examined during the pump photon energy scanning across the PBE. It is found that fluorescence from the 1D PC phosphor reaches its maximum when the pump photon energy coincides with the PBE, which is consistent with the theoretical prediction. In comparison with the reference phosphor, the fluorescence from the 1D PC phosphor is measured to be enhanced by a factor of 1.36.

Chloride Penetration and Aging Behaviors of Surface Protected Concrete with Silicone Material

Concrete structures are exposed to severe environment that may cause rapid decay, shortening their service life and raising maintenance and repair costs. Chloride ions will lead to the depassivation of reinforcing steel bars in concrete which is one of the most serious problems to the durability of concrete. Then, the prescriptive methodology is not a guarantee to obtain the desired service lives of 50 or 100 years. Surface treatment is commonly used to improve the resistance of concrete to chloride erosion. Using the silicone materials to an immersion treatment can effectively block the invasion of harmful substances,the resistance of concrete to chloride penetration with surface protection with silicone materials was evaluated. The results showed silicone can improve the resistance to chloride penetration than the non-protected concretes. As a kind of polymer materials, the aging behaviors of silane is a matter of urgent concern. Hence, the aging behavior of silane coated concrete is evaluated by the test of water absorption after 1000h xenon lamp aging, which exhibits excellent anti-aging performance of silane.

Aqueous counter collision using paired water jets as a novel means of preparing bio-nanofibers

This study involved a detailed investigation of a novel approach to reducing naturally occurring cellulose fibers into nanofibers solely by the use of aqueous counter collision (ACC) without any chemical modification. In this process, equivalent aqueous suspensions of cellulose are ejected from dual nozzles and collide at high speed and pressure. Even a few repetitions of the collision process are sufficient to produce nano-sized fibers dispersed in water. This work compared the ACC nano-pulverization of stable Iβ-rich and meta-stable Iα-rich cellulose samples. The ACC method is applicable to various kinds of polymeric materials with hierarchical structures, either natural or synthetic, as a means of preparing aqueous dispersions of nano-sized structures.

Comparative Study on Dispersion and Interfacial Properties of Single Walled Carbon Nanotube/Polymer Composites Using Hansen Solubility Parameters

Dispersion and interfacial strain transfer of single walled carbon nanotubes (SWNTs) are two major challenges for the utilization of SWNTs as reinforcements in polymer composites. Surface modifications could help change the dispersion and interfacial properties. In this study, nanocomposites were fabricated by solution blending 1 wt % SWNTs with various modification (nonmodified, nitric acid functionalized, and amine functionalized SWNTs) and three kinds of polymeric materials (polycarbonate, polyvinylidene fluoride, and epoxy). Chemical compatibilities between SWNTs and solvents or polymers are calculated by the Hansen solubility parameters (HSP) method. The dispersion of the SWNTs in solvents is evaluated by dynamic light scattering. The dispersion of SWNTs in polymers evaluated by a light optical microscope (LOM) generally agrees with the HSP prediction. The strain transfer from the matrix to SWNTs is mainly related to the dispersion, the bundle size, the residual thermal stresses on the sample, and, to lesser degree, the HSP.

A review on the assessment of polymeric materials used as corrosion inhibitor of metals and alloys

Corrosion control of metals is an important activity of technical, economical, environmental, and aesthetical importance. The use of inhibitors is one of the best options of protecting metals and alloys against corrosion. The toxicity of organic and inorganic corrosion inhibitors to the environment has prompted the search for safer corrosion inhibitors such as green corrosion inhibitors as other more environmental friendly corrosion inhibitors, most of which are biodegradable and do not contain heavy metals or other toxic compounds. Investigations of corrosion-inhibiting abilities of polymeric substances, e.g., plant gums, in addition to being environmentally friendly and ecologically acceptable, have shown that plant products are inexpensive, readily available, and renewable sources of materials. Need for more effective inhibitors has propelled companies such as the Montazhkhimzashchita Trust to develop a pool method of welding sheet vinyl, a method widely employed in gluing on roller sticky bands from thermoplast on a pipe. The article enumerates several kinds of polymeric materials which are suitable for use in combating corrosion, and several which have suitable strength characteristics as to serve in place of scarce expensive metals and alloys.