Polyvinylidene Chloride Research Articles

Polyvinylidene chloride supported L‐prolineamide as recoverable catalyst for asymmetric aldol reaction between ketone and aromatic aldehyde

AbstractA series of prolineamide modified by polyvinylidene chloride (PVDC) was synthesized and used as green recoverable organocatalysts for the asymmetric Aldol reactions between various ketones and aromatic aldehydes. The effects of solvent and catalyst dosage on the catalytic performances of as‐synthesized organocatalysts were investigated. It was found that as‐synthesized PVDC‐supported L‐prolineamides possessed good catalytic performance for the asymmetric Aldol reactions between cyclohexanone and a variety of aromatic aldehydes, affording high yields of up to 99%, excellent diastereoselectivities of up to above 8 : 92 d.r. value, and high enantioselectivities of up to above 92.3% e.e. value. In general, the catalytic performance of as‐synthesized organocatalysts closely depended on the catalyst dosage and solvent type as well. Particularly, as‐synthesized organocatalyst 1c, at a dosage of 5 mol % in 10 μL of water, exhibited high catalytic activity and stereoselectivity for the asymmetric Aldol reaction between cyclohexanone and p‐nitrobenzaldehyde at room temperature. In the meantime, it could be easily recovered and recycled, while the activity and enantioselectivity were nearly completely retained even after five cycles of recovery, showing promising application as an efficient green organocatalyst for the aforementioned asymmetric Aldol reactions. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Efficient asymmetric aldol reaction catalyzed by polyvinylidene chloride-supported ionic liquid/l-proline catalyst system

A series of polyvinylidene chloride (PVDC)-supported ionic liquids were derived from 4-dimethylaminopyridine and used together with l-proline in water as efficient asymmetric organocatalysts for direct asymmetric aldol reactions between cyclohexanone and a variety of aromatic aldehydes at room temperature. These PVDC-supported ionic liquids/l-proline catalyst systems have been used as asymmetric organocatalysts to afford the corresponding aldol products with a moderate to high isolated yield of up to 99%, with diastereoselectivity of up to 6:94, and excellent enantioselectivity of up to 98%. Furthermore, they could be easily recycled and showed only a slight reduction in selectivity after seven recycles.

포장방법이 강정의 저장 중 품질특성에 미치는 영향

본 연구에서는 강정의 포장방법 및 포장재질이 강정의 저장 중 품질특성에 미치는 영향을 조사하기 위해서 포장방법별로 개별포장, 대형포장 및 봉지포장의 3가지 방법과 8개의 포장재질을 사용하였다. 강정 포장은 (1) IP: OPP/PE+종이, (2) LP1: OPP/PE+종이, (3) LP2: OPP/PE+관, (4) LP3: OPP/PE+플라스틱, (5) BP1: OPP/PE, (6) BP2: OPP/DL/CPP, (7) BP3: PET/PE/CPP, (8) BP4: OPP/PVDC/PE/CPP로 구분하였다. 강정의 저장초기 지방산 조성은 linoleic acid(54.2%), oleic acid(24.1%), palmitic acid (11.2%) linoleic acid(6.0%) and stearic aicd(3.8%)이었으며, 저장중 수분함량, 수분활성도, 경도, 산가, 과산화물가를 측정하였다. 저장 중 수분함량의 변화가 늦게 나타난 시료는 LP2, BP4 > IP > LP3, BP1, BP2 > LP1 > BP3 순이었다. 수분활성도는 큰 차이를 보이지 않았으며, 경도는 IP, BP3 및 BP4는 저장 60일에 증가의 폭이 가장 크게 나타났다. 산가는 IP, LP1, LP2, LP3, BP1 및 BP2 경우 저장 40일에 기준치인 2.0 mg KOH/g 이하이었으며, 과산화물가는 IP, LP1, LP2 및 BP1의 경우 기준치인 40.0 meq/kg 미만이 20일째인 것으로 나타났다. 결론적으로 포장재질별로는 LP2와 BP1이 저장성이 우수하였으며 포장방법별로는 대형포장 >봉지포장 >개별포장 순으로 나타났다. This study was conducted to improve the packaging technology used for Gangjung and the product's quality characteristics during storage. Packaging materials consisting of (1) IP: OPP (oriented polypropylene)/PE (polyethylene) + Paper, (2) LP1: OPP/PE + Paper, (3) LP2: OPP/PE + Can, (4) LP3: OPP/PE + Plastic, (5) BP1: OPP/PE, (6) BP2: OPP/DL/CPP (cast polypropylene), (7) BP3: PET/PE/CPP, and (8) BP4: OPP/PVDC (polyvinylidene chloride)/PE/CPP were used. The major fatty acids including 54.2% linoleic acid, 24.1% oleic acid, 11.2% palmitic acid and 6.0% linoleic acid were assessed. The packages effective in maintaining moisture were in the order of LP2, BP4 > IP > LP3, BP1, BP2 > LP1 > BP3. There were no significant differences in water content and the products in IP, BP3, and BP showed the highest level in the increase in hardness on day 60 of storage. Acid values of IP, LP1, LP2, LP3, BP1, and BP2 were maintained at <2.0 during 40 days of storage. IP, LP1, LP2 and BP1.

Effect of protective atmospheres on physicochemical, microbiological and rheological characteristics of sliced Mozzarella cheese

Mozzarella cheese slices packaged in bags of polyvinylidene chloride under vacuum (V) and using a gas mixture of equal parts of CO2 and N2 (G) were stored at 4°C for 8 weeks and analysed at different storage times by physicochemical, microbiological and rheological characterization. Expected values of moisture, total nitrogen, soluble nitrogen at pH 4.6, and chloride contents and of pH were observed. The degradation of αs1-casein was greater than β-casein degradation, while no significant differences were observed due to the packaging methods. Coliform microorganisms were not detected, while levels of moulds and yeasts counts were acceptable. Expected values of total mesophile counts were obtained. The temperature at crossover moduli (Tc) was determined from temperature sweeps carried out by rheometry. Greater values of Tc were observed in samples G. The influence of temperature on complex viscosity was studied by an Arrhenius-type equation. Activation energy values were obtained from the solid-like region (20–40°C) and liquid-like region (40–60°C). A more rapid change in viscosity with temperature was observed when storage time increased and when storage method V was used.

Formation of Defect-Free Latex Films on Porous Fiber Supports

We present here the creation of a defect-free polyvinylidene chloride barrier layer on the lumen-side of a hollow fiber sorbent. Hollow fiber sorbents have previously been shown to be promising materials for enabling low-cost CO(2) capture, provided a defect-free lumen-side barrier layer can be created. Film experiments examined the effect of drying rate, latex age, substrate porosity (porous vs nonporous), and substrate hydrophobicity/hydrophilicity. Film studies show that in ideal conditions (i.e., slow drying, fresh latex, and smooth nonporous substrate), a defect-free film can be formed, whereas the other permutations of the variables investigated led to defective films. These results were extended to hollow fiber sorbents, and despite using fresh latex and relatively slow drying conditions, a defective lumen-side layer resulted. XRD and DSC indicate that polyvinylidene chloride latex develops crystallinity over time, thereby inhibiting proper film formation as confirmed by SEM and gas permeation. This and other key additional challenges associated with the porous hollow fiber substrate vs the nonporous flat substrate were overcome. By employing a toluene-vapor saturated drying gas (a swelling solvent for polyvinylidene chloride) a defect-free lumen-side barrier layer was created, as investigated by gas and water vapor permeation.

Molecular sieve carbons for CO2 capture

With the current interest in controlling greenhouse gases, there is a new focus on materials that can discriminate between gas molecules by capturing those gases which must be curtailed and releasing those which pose no adverse effects to the atmosphere. Although zeolites can be applied to such tasks, molecular sieve (MS) carbons have an additional advantage in their ability to both adsorb and desorb molecules cyclically with comparatively little energy demand.This paper describes studies of commercial ATMI carbons obtained from polyvinylidene chloride pyrolysis that have experienced different levels of activation and additives to modify the sizes of pore ‘portals’ (i.e., those pores which orchestrate movement of molecules from the gas phase into the inner structure of the carbon). The structures are probed using molecules in the 0.3–0.68nm size range. One significant feature of these materials is that total pore volume for smaller molecules is maintained during the ‘tailoring’ of the portal pore size. These carbons have additional benefits such as high strength and high density, becoming ideal candidates for capturing CO2. Data for select carbons indicate capacities at ambient conditions for CO2 of >140v/v (∼20wt.%) and, in simulated power plant exhaust, Henry’s Law Separation Factors >6. Through collaboration with SRI International, ATMI has developed carbons that exhibit >97% capture of CO2 in such streams with subsequent desorption of 98% purity CO2 in the stripper section of a pilot-scale unit. In this application, these carbons outperform the claims made for MOFs and other similar materials.

PROCESS DEVELOPMENT OF SHELF‐STABLE CHINESE STEAMED BUN

ABSTRACT This research aims to develop a shelf‐stable Chinese steamed bun by using Aw and pH as hurdle. The effects of adding glycerol and lactic acid on Aw, pH and sensory qualities were studied. It was found that optimum condition is reached with the addition of 2.5% glycerol and 0.25% lactic acid, which could reduce Aw and pH to 0.912 and 5.78, respectively. From shelf‐life study, the aerobic plate count, Aw, and pH of control and hurdle‐treated products (HP) with different levels of calcium propionate (CaP), packed in polyvinylidene chloride pouches and stored at 30 ± 2C, were investigated. The HP without CaP can be stored for at least 16 days, similar to HP with CaP, and Aw increased slightly while pH did not change. From textural measurement and sensory evaluation of HP without CaP compared with control sample, the shelf life of this product can be extended to 8 days.PRACTICAL APPLICATIONSThe result from this study can be used to develop a safe and acceptable Chinese steamed bun by using hurdle technology, aiming to be shelf‐stable at ambient temperature. The archived research led to the benefit of industrial production for better distribution and marketing of this product.

Recovery of polypropylene and polyethylene from packaging plastic wastes without contamination of chlorinated plastic films by the combination process of wet gravity separation and ozonation

Wet gravity separation technique has been regularly practiced to separate the polypropylene (PP) and polyethylene (PE) (light plastic films) from chlorinated plastic films (CP films) (heavy plastic films). The CP films including poly vinyl chloride (PVC) and poly vinylidene chloride (PVDC) would float in water even though its density is more than 1.0 g/cm 3. This is because films are twisted in which air is sometimes entrapped inside the twisted CP films in real existing recycling plant. The present research improves the current process in separating the PP and PE from plastic packaging waste (PPW), by reducing entrapped air and by increasing the hydrophilicity of the CP films surface with ozonation. The present research also measures the hydrophilicity of the CP films. In ozonation process mixing of artificial films up to 10 min reduces the contact angle from 78° to 62°, and also increases the hydrophilicity of CP films. The previous studies also performed show that the artificial PVDC films easily settle down by the same. The effect of ozonation after the wet gravity separation on light PPW films obtained from an actual PPW recycling plant was also evaluated. Although actual light PPW films contained 1.3% of CP films however in present case all the CP films were removed from the PPW films as a settled fraction in the combination process of ozonation and wet gravity separation. The combination process of ozonation and wet gravity separation is the more beneficial process in recovering of high purity PP and PE films from the PPW films.

Synthesis and characterization of novel PEO–MCM-41/PVDC nanocomposite membrane

Poly vinylidene chloride (PVDC) membranes with contents of MCM-41 particles (0, 1, 2 and 3wt.%, by weight of PVDC) were prepared by a phase inversion process. MCM-41 nanoparticles with 40–90nm particle size were prepared by in situ assembly of tetraethylorthosilicate (TEOS, Merck) as inorganic precursors and cetyltrimethylammonium bromide (CTAB, Merck) then modified by polyethylene oxide (PEO) as a hydrophilicity increaser. The structure of nanoparticles was characterized by XRD, TEM, particle size analysis and N2 adsorption techniques. The synthesized nanocomposite membranes were then characterized using scanning electron microscopy (SEM/EDX), tensile stress tests, thermogravimetric analysis (TGA), FTIR spectra, contact angle technique, water flux and BSA rejection to investigate the influence on the final properties of the developed membrane. The experiment results confirmed that the addition of modified MCM-41 particles could effectively improve membrane hydrophilicity, hydrodynamic characteristics, mechanical property, thermal stability and especially membrane flux.

Dynamic Study of Ceramide Channels with a Microfluidic System

A novel microfluidic system enabling effective and robust dynamic perfusion of reagents directly to an on-chip phospholipid bilayer membrane was developed to study membrane channels. Here we report its application to the study of the dynamics of ceramide channels. The microfluidic system consists of a planar phospholipid membrane (PPM) formed across a 60-100 µm diameter aperture in a polyvinylidene chloride film formed within a thermoplastic polycarbonate substrate containing a microfabricated fluidic network. The volume of the network before the aperture is 2.3µL and the chamber beneath the aperture is 20nL. Constant pumping rates up to 5µL/min can be used without disrupting the fragile membranes and so the solution bathing the membrane can be completely replaced in less than 1 minute. Transmembrane current is monitored continuously under voltage-clamp conditions. For ceramide channel experiments, the membrane-forming solution was 5 mg diphytanoyl PC, 5 mg asolectin, 0.5 mg cholesterol, 0.13 mg C16-ceramide in 1 ml of hexanol/hexadecane (v/v 10:1). The sphingolipid, ceramide, self-assembles into large channels in phospholipid membranes and is known to play an important role in apoptosis. In our studies, channel dynamics were observed by inducing disassembly and reassembly of ceramide channels formed spontaneously in the PPMs. Perfusion with La3+ resulted in rapid disassembly. Channel reassembly occurred after washing away the La3+ using EDTA. Multiple cycles of disassembly and reassembly could be performed on the same membrane. Similar studies were performed by perfusing in Bcl-xL, a potent apoptosis inhibitor. Bcl-xL disassembles the channels rapidly but the reassembly is slow. The results are consistent with ceramide channels existing in equilibrium with ceramide monomers or aggregates in the membrane and this equilibrium can be shifted by interaction with chemical agents. Supported by grants from NIH (R21EB009485) and NSF (MCB-0641208).

Microfluidic generation and dynamically switching of oxygen gradients applied to the observation of cell aerotactic behaviour

We propose a simple but reliable technology for the generation of oxygen gradient in microfluidic devices, which is useful for cell aerotaxis study. The technology is based on single layer patterning of polydimethylsiloxane (PDMS) and integration of a thin layer polyvinylidene chloride (PVDC). The PDMS layer was patterned to define a cell chamber embedded by two micro-channels, whereas the PVDC layer acts as barrier to prevent the diffusion of gas outside into the layer, thus forcing gas to diffuse along the PDMS layer. As a result, a linear oxygen gradient in the cell chamber can be established by controlling the gas contents inside the two micro-channels. By using 3-way valves, such a linear gradient could be changed from one state to another. To demonstrate the application potential of this approach, we used this device in the study of the aerotactic behaviour of magnetospirillum sp. strain AMB-1 and observed a stable and reversible cell migration by changing the gas distribution in the cell chamber. This system should be useful for better understanding of cell aerotactic mechanism.

Osteoanagenesis after transplantation of bone marrow-derived mesenchymal stem cells using polyvinylidene chloride film as a scaffold

The aim of this study was to develop a new cell transplantation technique for osteoanagenesis at bone defect sites. Polyvinylidene chloride (PVDC) film was evaluated because of its good biocompatibility and flexibility. We used this film as both a cell scaffold and a barrier membrane. Initially, the cell compatibility of the PVDC film for fibroblast-like cells and osteoblast-like cells was confirmed. Subsequently, bone marrow cells were obtained from rats and cultured on PVDC films in two kinds of medium. The PVDC films with bone marrow-derived mesenchymal stem cells (MSCs) were then applied to critical-sized bone defects in the calvarial bone of rats. After the transplantation, the surgical sites were dissected out and evaluated by soft X-ray radiography, micro-CT analysis and histological examinations. The bone marrow-derived MSC-transplanted rats showed greater bone regeneration than the control rats. Therefore, PVDC film is considered to be useful as a scaffold for bone regeneration.

Study of Amount of Evaporation Residue in Extracts from Plastic Kitchen Utensils into Four Food-simulating Solvents

The amount of evaporation residue was investigated as an index of total amount of non-volatile substances that migrated from plastic kitchen utensils into four food-simulating solvents (water, 4% acetic acid, 20% ethanol and heptane). The samples were 71 products made of 12 types of plastics for food contact use. The amount was determined in accordance with the Japanese testing method. The quantitation limit was 5 µg/mL. In the cases of polyethylene, polypropylene, polystyrene, acrylonitrile styrene resin, acrylonitrile butadiene styrene resin, polyvinyl chloride, polyvinylidene chloride, polymethylpentene, polymethylmethacrylate and polyethylene terephthalate samples, the amount was highest for heptane and very low for the other solvents. On the other hand, in the cases of melamine resin and polyamide samples, the amount was highest for 4% acetic acid or 20% ethanol and lowest for heptane. These results enabled the selection of the most suitable solvent, and the rapid and efficient determination of evaporation residue.

CHEMICAL SPECIATION OF CHLORINE PRESENT IN PARTICULATE COMBUSTION PRODUCTS OF ORGANIC CHLORINE COMPOUNDS BY EMPLOYING HIGH-RESOLUTION PIXE ANALYSIS

The chemical speciation of chlorine ( Cl ) in particulate matter samples produced by the laboratory burning of organic Cl compounds was tested by employing the high-resolution measurement of K β X-rays based on a wavelength-dispersive proton-induced X-ray emission (WD-PIXE) technique. Targets for proton irradiation were prepared by depositing particulate burning products on aluminum foils placed on a simple barrel burner. Standard inorganic ( NaCl , MgCl 2, CaCl 2, NH 4 Cl , and AlCl 3) and organic (polyvinyl chloride and polyvinylidene chloride) Cl compounds were prepared for spectral comparison. We found that the Cl - K β1 peak energies for these organic compounds are higher by approximately 1 eV than those for inorganic compounds. For burning products of these organic compounds, the peak energies were found to be located between those for organic and inorganic compounds. This result indicates that the organic Cl compounds were decomposed to smaller molecules during the burning process but these fragments still existed in the organic form.

Modified Three-Dimensional Brain Model for Study of the Trans-sylvian Approach

The trans-sylvian approach is one of the most frequently employed neurosurgical procedures, but it is difficult for medical students to understand the approach stereoscopically. A three-dimensional model equipped with an arachnoid membrane and sylvian vein was developed which can be repeatedly used to simulate surgery for the education of medical students and residents in the trans-sylvian approach. The model was prepared using existing models of the skull bone, brain, and cerebral artery. Polyvinylidene chloride film, commonly used as plastic wrap for food, was adopted for the arachnoid membrane, and wetted water-insoluble tissue paper for the arachnoid trabeculae. The sylvian vein was prepared by ligating woolen yarn with cotton lace thread at several sites. Students and residents performed the trans-sylvian approach under a microscope, and answered a questionnaire survey. Using this model, simulation of division of the arachnoid membrane and arachnoid trabeculae, and dissection of the sylvian vein was possible. In the questionnaire, the subjects answered 8 questions concerning understanding of the stereoscopic anatomy of the sylvian fissure, usefulness of the simulation, and interest in neurosurgical operation using the following ratings: yes, very much; yes; somewhat; not very much; or not at all. All items rated as 'yes, very much' and 'yes' accounted for more than 70% of answers. This model was useful for medical students to learn the trans-sylvian approach. In addition, repeated practice is possible using cheap materials, which is advantageous for an educational model.

Photoluminescent and thermal behavior of 120 MeV silicon and 84 MeV oxygen ion irradiated PVDC

Photoluminescent, structural and thermal changes induced in polyvinylidenechloride (PVDC) films by irradiation with energetic silicon and oxygen ions have been determined using different techniques viz PL, FTIR, UV–vis, XRD, TGA and AFM. Noticeable photoluminescence was observed in PVDC after irradiation with 84MeV oxygen ions at fluence 3.2×1011ionscm−2, which is attributed to the small carbon cluster formed in the polymer due to irradiation. Quenching and shifting in the position of the PL band towards the longer wavelength side of the spectrum was observed with the increase in ion fluence. UV–vis and FTIR analysis have strongly corroborated the results of PL spectroscopy. X-ray diffractograms and TGA curves show decrease in crystallinity and weight loss, respectively, of PVDC films after irradiation. The strong correlation between the behaviors of different properties were analyzed and discussed in the present paper.

Multifractal analysis of the tensile fracture morphology of polyvinylidene chloride/glass fiber composite

In the present work, the building panel of glass fiber reinforced polyvinylidene chloride composite was prepared and the tensile fracture surfaces of the composites were investigated by the box-counting method of multifractal theory. It suggested that the tensile fracture surface of polyvinylidene chloride/glass fiber (PVDC/GF) composite exhibits multifractal features and the tensile fracture surface morphology of the composite have a strong dependence on the mechanical properties. The results showed that the variation of glass fiber content would lead to the change of mechanical properties, which were responsible for the tensile fracture morphology of PVDC/GF composite. Consequently, the gray value distribution characterizing the surface morphology on the tensile fracture surface would become more non-uniform or less due to this change. The multifractal spectrum could correspondingly mirror this variation according to multifractal methodology. It indicated that the width in multifractal spectrum is sensitive to the morphology of the tensile fractured surface. It is concluded that the multifractal spectrum is the result of the change in mechanical properties of the composites. Additionally, it also suggested that the tensile fracture of the composite is the result of the competition between ductile fracture and brittle fracture by comparing the multifractal spectra and the multifractal spectra would correspondingly change due to this competition. The more the percentage of ductile fracture is, the more rough the fracture surface, the larger the width in the multifractal spectrum. Therefore, it is thought that the multifractal spectrum could feature the rough morphology of the tensile fractured surface and the mechanical properties quantitatively.

Bionic Composite Material Simulating the Optical Spectra of Plant Leaves

Though many physical models have been proposed to simulate the spectra of plant leaves, there are few reports on the material simulation of plant leaves. In order to prepare a material that could simulate the reflectance spectra of plant leaves, the spectral reflectance characteristics of plant leaves and their forming mechanism were analyzed. The study indicated that the reflectance spectra of plant leaves exhibits four common characteristics, which were determined by the spongy inner structure and biochemical contents (chlorophyll, water) of plant leaves. In our procedure, the chlorophyll was concealed into the high-oxygen-barrier polyvinyl alcohol (PVA) film to improve its photostability, and the water was sealed into the bag of high-vapor-barrier polyvinylidene chloride (PVDC) to prevent its vaporization loss. Subsequently, taking the structures of plant leaves and petals as simulating models and considering the limits of PVA film and PVDC bag, a novel bionic composite material constituted with three layers was designed and prepared. The spectral tests and endurance experiment show that the bionic composite material exhibits almost the same reflectance spectrum with those of green leaves, and its spectrum changes little after sunlight treatment for three months, which proves a good sunlight endurance of this bionic composite material.

The Bonding Structure of the Various High Purity or Binderless Polycrystalline Cubic Boron Nitride Compacts Sintered at 5 to 7GPa and 1600 to 2000 °C

The cBN-cBN direct bonding structure of some cBN compacts made by the method of the direct conversion of the pyrolytic-BN (pBN) or wurtzite-BN (wBN) to cubic-BN at the pressure of 7GPa and temperature 2000 °C and the cBN compact made by the method of sintering the cBN powder along with polyvinylidene chloride (PVDC) at the condition of 5.5GPa and 1600 °C has been studied. The XRD, SEM, TEM analysis and the wear resistance on the ductile cast iron machining has been investigated. While the XRD analysis of the above cBN samples showed that all samples consist only of cBN, and the SEM observation showed that they all have the cBN-cBN direct bonding structure, A STEM analysis showed the existence of the impurities at the cBN crystal boundary. The starting materials and the sintering method affect the degree of these impurities.

Poly(vinylidene chloride)-based carbon as an electrode material for high power electric double layer capacitors

A series of poly vinylidene chloride (PVDC) based activated carbons was prepared by carbonization at 600-1 100 ℃. Their formation,crystallinity,surface area and pore structure were characterized by thermogravimetry,X-ray diffraction and nitrogen adsorption. The electrochemical performance was investigated by cycle voltammetry,AC impedance and galvanostatic charge/discharge in a 30 % (mass fraction) KOH electrolyte. Results showed that the structure of PVDC-based carbons was amorphous and their high surface area (874-969 m2/g) and abundant micropores were formed during the solid phase carbonization. PVDC-based carbon had a high gravimetric capacitance and specific capacitance per surface area,owing to its optimum pore size distribution suitable for the formation of electric double layers. The PVDC-based carbon heat-treated at 900 ℃ had a maximum capacitance and an excellent power performance. The specific capacitance can reach as high as 256.9 F/g at low discharge current density (50 mA/g) and the capacitance retention ratio is 76.5% at high current density (5 000 mA/g). The electrical conductivity of PVDC-based carbon increased and the diffusion resis￣tance of electrolyte ions in pores decreased with increasing carbonization temperature,and the rate performance of the electric double layer capacitor is improved as a result.