China Leather and Footwear Industry Research Institute

Beijing, China

China Leather and Footwear Industry Research Institute

Beijing, China

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Ding Z.,China Leather and Footwear Industry Research Institute | Pang X.,China Leather and Footwear Industry Research Institute | Albu L.,INCDTP Division Leather and Footwear Research Institute
Leather and Footwear Journal | Year: 2012

Collagen protein was extracted from cowhide leather solid waste with chromium by hydrolysis of alkaline and cycle method. Then different molecular weight ranges of collagen protein were got by ultrafiltration. Collagen protein was characterized by High Performance Liquid Chromatography (HPLC) and Multiangle Laser Scattering meter and the average molecular weight was got, based on that the average molecular structure model was established. The study will provide the theory basis for the modification research of collagen.


Liu J.,Dalian Polytechnic University | Feng N.,Dalian Polytechnic University | Chang S.,China Leather and Footwear Industry Research Institute | Kang H.,CAS Institute of Chemistry
Applied Surface Science | Year: 2012

In order to improve the compatibility of magnesium hydroxide particles [Mg(OH) 2] and polymer matrix, poly(glycidyl methacrylate) (PGMA) grafted from magnesium hydroxide particles were synthesized via surface-initiated atom transfer radical polymerization (SI-ATRP). In this work, two approaches for the immobilization of ATRP initiator on the magnesium hydroxide particles surface were compared and selected. The density of initiator was significantly increased by the method of introducing more hydroxyl groups via ATRP of 2-hydroxyethyl methacrylate (HEMA) on the surface. The percentage of bromine atom for the initiator-functionalized magnesium hydroxide particles [Mg(OH) 2-g-PHEMA-Br] reached to 1.75%, compared to 0.48% for Mg(OH) 2-Br determined by XPS analysis. The surface-initiated ATRP of glycidyl methacrylate (GMA) can be conducted in a controlled manner, as revealed by the linear kinetic plot, linear increase of number average molecular weight (M n) with monomer conversions, and the relatively narrow molecular weight distributions (M w/M n ∼ 1.4) of PGMA chains. The percentage of grafting PG (%) and the thickness of the grafted polymer layer increased with the increasing of polymerization time and reached to 116.6% and 197.6 nm after 300 min respectively. As for the polymerization with different initial monomer concentration, the number average molecular weights (M n) and weight average molecular weights (M w) of PGMA increased with the increasing of initial monomer concentration. TGA indicated that the initial decomposition temperature of Mg(OH) 2-g-PHEMA-PGMA composite particles (253°C) was much lower than that of unmodified magnesium hydroxide particles (337°C). © 2012 Elsevier B.V. All rights reserved.


Wang X.,China Leather and Footwear Industry Research Institute | Feng N.,Dalian Polytechnic University | Chang S.,China Leather and Footwear Industry Research Institute
Polymer Composites | Year: 2013

The ternary composites of 1,4-cis polybutadiene rubbers (BR), styrene-butadiene rubber (SBR), and natural rubber (NR) foams containing chemical blowing agents Oxybis (benzene sulfonyl) hydrazide (OBSH) were prepared by two-stage compression molding technique with various precured degrees. Foam force rheometer indicated that the cure rate was match with foaming rate at precured degree of 30%, which the time of the maximum foaming rate was earlier only 14 s than that of the maximum cure rate. SEM presented that the number of cell was denser at precured degree of 30% than those with other precured degrees. The average cell size declined, cell wall thickness became thicker, and cell distribution became narrower just as precured degree was increasing. The results of crosslinking density was measured by equilibrium swelling technique in good agreement with that of magnetism resonance crosslinking density spectrometer measurement, which crosslinking density was increased as precured degrees increased. Differential scanning calorimeter showed that each curve exhibits two steps in heat capacity for BR/SBR/NR foams. With further increase of precured degrees, the two groups of Tgs were all shift to the higher temperature, and the area of the melting peak decreased gradually between -20°C and -40°C. TGA results demonstrated that BR/SBR/NR foams with various precured degrees obtained better thermal stability than those of non-precured foams. The high density of polymeric foams exhibits the high mechanical properties such as tensile strength, tear strength, and elongation at break. The inflection points of density, cell density, and hardness were all appeared at precured degree of 30%. © 2013 Society of Plastics Engineers.


Liang J.,Dalian Polytechnic University | Liang J.,China Leather and Footwear Industry Research Institute | Chang S.,China Leather and Footwear Industry Research Institute | Feng N.,Dalian Polytechnic University
Journal of Applied Polymer Science | Year: 2013

In this work, the white-silica-filled vulcanizates of brombutyl rubber (BIIR)/cis 1,4 polybutadiene rubbers (BR) with hydrogenated aromatic hydrocarbon (C5) petroleum resins were prepared by compression molding, and the effects of C5 petroleum resin content on the damping behaviors and mechanical properties of BIIR/BR vulcanizates were investigated by foam force rheometer, dynamic mechanical analysis (DMA), scanning electron microscopy, and mechanical measurements. The results of this study showed that, the C5 resins could retard the vulcanization, and reduce the crosslink density and Mooney viscosity of vulcanizates. The DMA curves exhibited two independent peaks of loss factor (tanδ) corresponding to the glass transition of BR and BIIR vulcanizates, respectively. The addition of C5 resin had a positive impact on the damping of BIIR/BR vulcanizates, with the increment content of C5 resin, the main tanδ peaks shifted significantly to higher temperature and the effective damping temperature range was broadened remarkably, especially in the range of the BIIR glass transition. The mechanical properties such as tensile strength and abrasion performance were influenced by the C5 resin and the changes in mechanical properties were mainly due to the decline of crosslink density and the improvement of filler dispersion. © 2013 Wiley Periodicals, Inc.


Wang X.,Dalian Polytechnic University | Feng N.,Dalian Polytechnic University | Chang S.,China Leather and Footwear Industry Research Institute | Zhang G.,Dalian Polytechnic University | And 2 more authors.
Journal of Applied Polymer Science | Year: 2012

Intumescent flame retardant thermoplastic polyolefin (TPO) composites were prepared to study the relationships between their structure of charred layer (including of the multicellular intumescent layer and the charry layer) and flame retardant properties. They were characterized using the LOI and UL-94 test, which indicated that the best fire retardant behavior (V-0 rating and LOI reach to 28.1%) was obtained at the formulation of TPO/ammonium dihydrogen phosphate/starch (100/60/20). Thermal gravimetric analysis demonstrated that the presence of ammonium dihydrogen phosphate/starch promoted the esterification and carbonization process in lower temperature range while enhancing the thermal stability of intumescent flame retardant TPO in high-temperature range. Scanning electron microscope and optical microscope were shown that, with combustion time prolonged, the intumescent layers obtained greater number of cells, and the charry layer became more compact while the size of the carbon granules became smaller on the surface. Introduction of starch had an obvious effect on the structure of the intumescent and charry layers. The charry layer of the composites with the content of 20 phr starch was more compact and uniform than that of the composites with 50 phr. The weight ratio of ammonium dihydrogen phosphate to starch in the intumescent flame retardant was fixed as 3: 1 which cooperated with each other well to promote a compact charry layer and to obtain the better flame retardancy performance. Therefore, the better the charred layers produced, and the better flame retardant properties they obtained. © 2011 Wiley Periodicals, Inc.


Qiang T.,Shaanxi University of Science and Technology | Gao X.,Shaanxi University of Science and Technology | Ren J.,Shaanxi University of Science and Technology | Chen X.,China Leather and Footwear Industry Research Institute | Wang X.,Shaanxi University of Science and Technology
ACS Sustainable Chemistry and Engineering | Year: 2016

This paper discusses the terminal carboxyl groups of the hyperbranched polymer (HPAE-C) complexing Al3+ in aluminum sulfate to synthesis a new chrome-free tanning agent (HPC-Al). The molecular structure of HPC-Al was characterized and analyzed by IR, UV, and XRD. In the tanning process, the results indicate the following: (1) The shrinkage temperature of HPC-Al tanning leather is 79.5°C. (2) The shrinkage temperature is greater than 95°C after chrome retanning and about 87°C after zirconium retanning. (3) It has greatly improved the fullness, softness, and physical-mechanical properties of the leather. Meanwhile, the environmental impact assessment after tanning was evaluated. The results show that biochemical oxygen demand, total dissolved solids, and total suspended solids are reduced. This indicates that the use of HPC-Al as a tanning agent, with chrome-free or chrome-less tanning, can be achieved. © 2015 American Chemical Society.


Xiaoxing L.,China Leather and Footwear Industry Research Institute
Journal of the Society of Leather Technologies and Chemists | Year: 2015

Some of the basic properties of tannery sludge were examined by using GC-MS, atomic absorption spectrophotometry and other methods. The effect of enzyme pre-treatment for tannery sludge was studied. The results showed that the alkaline protease 2709 and neutral protease As.1398 can effectively promote the soluble chemical oxygen demand of tannery sludge. Alkaline protease 2709 enzymatic pre-treatment can promote anaerobic digestion of tannery sludge. It can increase the rate of decomposition of organic matter by 23.01%, and increase methane gas production by 144.89%. Used together with ultrasound pre-treatment alkaline protease 2709 and can promote anaerobic digestion and increase the rate of decomposition of organic matter by 65.63% and gas production by 425%.


Liu N.,Tianjin University of Science and Technology | Ding Z.,China Leather and Footwear Industry Research Institute | Cheng B.,Tianjin University of Science and Technology | Pang X.,China Leather and Footwear Industry Research Institute | Cheng Z.,China Leather and Footwear Industry Research Institute
Advanced Materials Research | Year: 2012

In this study, Regenerated chrome tanning agent is prepared from chrome sludge by hydrogen peroxide oxidation. The regenerated chrome tanning agent was characterized by IR which reveals that organic acid and protein polypeptide combined with chrome have been mostly removed. A small part of organic acid and protein polypeptide, not oxidized, increases the masking effect of the product. The application results show that the shrinkage temperature (Ts) of wet blue leather can reach 100°C and the leather has good feeling of handle and fullness which shows it has same properties with commercial chrome tanning agent. © (2012) Trans Tech Publications.


Zhao Y.,China Leather and Footwear Industry Research Institute | Qi X.,China Leather and Footwear Industry Research Institute
Chinese Journal of Chromatography (Se Pu) | Year: 2010

An effective method for the determination of dimethyl fumarate (DMF) in leather and textiles by gas chromatography-tandem mass spectrometry (GC-MS/MS) was developed. Samples of leather or textiles were extracted with ethyl acetate and concentrated, DMF was separated on a VF-5ms column and analyzed by GC-MS/MS after solid phase extraction (SPE) process. The result shows that this method is sensitive, accurate and reliable. The linear relationship was perfect and the interference with background signal was further eliminated after pretreatment, SPE and GC-MS/MS analytical conditions were optimized. The average recoveries of DMF in leather and textiles at three levels ranged from 84% to 93%, the relative standard deviations (n = 6) were lower than 7.2%, the limits of detection in the range from 0.012 to 0.039 mg/kg (S/N = 3), the correlation coefficient was 0. 999 0 over the range 0. 05 - 100 mg/L. It has been applied to routine determination of DMF in leather and textiles with satisfactory results.


Li X.,China leather and footwear industry research institute | Chen J.,China leather and footwear industry research institute | Jia J.,China leather and footwear industry research institute
Applied Mechanics and Materials | Year: 2013

This paper studied a kind of new bactericides material. We synthesized a kind of hyperbranched polymer. It had bactericidal performance. Cyanuric chloride reacted with 1,3,5- trihydroxybenzene. Then got a kind of polyhydric of hyperbranched polymer. This hyperbranched polymer reacted with hydrobromic acid, diethylenetriamine, chloroacetic acid in deferent steps. And finally we got a new kind of hyperbranched polymer bactericides.The relevant key factors to influence those reaction was studied. This paper created a new direction of bactericides material development. © (2013) Trans Tech Publications, Switzerland.

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