Bibliographic Information

New method for characterizing grafting ratio in flame retardant polymers.     Wu, Shaoli; Guo, Dong; Wang, Jianqi.    National Laboratory of Flame Retarded Materials,  Beijing Institute of Technology,  Beijing,  Peop. Rep. China.    Beijing Ligong Daxue Xuebao  (1999),  19(3),  389-392.  CODEN: BLXUEV  ISSN: 1001-0645.  Journal  written in Chinese.    CAN 132:279855    AN 1999:733212    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

A new way of characterizing grafting ratio of polymeric surface was investigated, and the relationship of retardancy performance and grafting ratio was studied.  Electron beam preirradn. was used to graft methacrylic acid monomer on the surface of ABS polymer under the various conditions.  Mass method and area method were used to indicate the grafting ratio, oxygen index (Loi) of the grafted polymer was measured to study grafting/flame retardancy relationship.  The relation between mass grafting ratio and Loi was less linear.  However, the relation between grafting ratio based on the area method and Loi was linear partly.

Bibliographic Information

Investigation of thermal degradation, flame retardance and smoke suppression of rigid PVC by using the cone calorimeter.     Li, Bin; Wang, Jianqi; Ding, Yangbing.    National Flame Retarded Materials Lab.,  Beijing Inst. of Technology,  Beijing,  Peop. Rep. China.    Gaofenzi Cailiao Kexue Yu Gongcheng  (1999),  15(5),  124-127.  CODEN: GCKGEI  ISSN: 1000-7555.  Journal  written in Chinese.    CAN 132:3763    AN 1999:687055    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

The effects of copper oxide on the thermal degrdn., flame retardance, and smoke suppression of poly(vinyl chloride) (PVC) were investigated through various parameters such as wt. loss rate (MLR), heat release rate (HRR), effective heat of combustion (EHC), smoke prodn. rate (SPR) and time of ignition (TTI), etc., which were measured at an irradiance of 25 kW/m2 from Cone calorimeter.  The presence of CuO could: (1) promote the reaction of HCl-elimination earlier and more quickly and decrease the rate of segment pyrolysis; (2) enhance the amt. of char formed; (3) decrease HRR, SPR and total smoke prodn. significantly; (4) shorten TTI of PVC; (5) produce volatiles to burn in the gas phase; (6) increase total heat release because copper oxide caused char afterglow.

Bibliographic Information

Approaches to and characterization of the flame retardancy of polymers by plasma treatment and grafting of acrylic monomers onto EVA copolymers.     Shi, Lishun; Wang, Jianqi.    School of Chemical Engineering and Material Science,  Beijing Inst. of Technology,  Beijing,  Peop. Rep. China.    Gaofenzi Cailiao Kexue Yu Gongcheng  (1999),  15(5),  91-94.  CODEN: GCKGEI  ISSN: 1000-7555.  Journal  written in Chinese.    CAN 132:3755    AN 1999:687027    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

Ethylene-vinyl acetate copolymer was treated with Ar plasma followed by grafting with methacrylic acid, acrylic acid, and acrylamide, resp.  Factors affecting the grafting rate included plasma treatment condition, graft polymn. time, monomer concn., and subsequent sapon. time.  Measurements of time of ignition, limiting oxygen index, and char residues showed that the flame retardance of the copolymer improved after graft polymn. treatment.

Bibliographic Information

An XPS study of the radiation-induced effect on the thermal degradation and charring of butadiene and its copolymers.     Hao, Jianwei; Wu, Shaoli; Wilkie, Charles A.; Wang, Jianqi.    National Laboratory of Flame Retardant Materials, School of Chemical Engineering and Materials Science,  Beijing Institute of Technology,  Beijing,  Peop. Rep. China.    Polymer Degradation and Stability  (1999),  66(1),  81-86.  CODEN: PDSTDW  ISSN: 0141-3910.  Journal  written in English.    CAN 131:311166    AN 1999:594392    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

A pseudo-in-situ XPS approach shows that crosslinking induced by irradn. may lead to char formation even though it shows only a small or no effect on the onset temp. of degrdn.

Bibliographic Information

Studies on interfacial chemistry of polypropylene/aluminum hydroxide composites.     Ren, Diansheng; Wang, Jianqi.    Tianjin Electronic Materials Research Institute,  Tianjin,  Peop. Rep. China.    Surface and Interface Analysis  (1999),  28(1),  170-172.  CODEN: SIANDQ  ISSN: 0142-2421.  Journal  written in English.    CAN 131:323289    AN 1999:589931    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

In order to improve the mech. properties of polypropylene (PP)/Al(OH)3 composites, the surface of Al(OH)3 was treated with a KH-792 silane coupling agent, and acrylic acid (AA) was grafted onto the PP.  The interface between the PP-g-AA (PP grafted by AA) and silane coupling agent, and the interface between the Al(OH)3 and silane coupling agent were investigated by XPS.  The results show that the siloxane group of the KH-792 coupling agent can bond chem. with the Al(OH)3 surface, and the amine group at the other site of the coupling agent can bond chem. with the acrylic acid of PP-g-AA.  The mech. properties of PP/Al(OH)3 composites were significantly improved in high loadings.

Bibliographic Information

Fluorination of PET surface and its structure characterization by x-ray photoelectron spectra (XPS) method.     Zhang, Liang; Zheng, Ning; Wang, Jianqi; Fan, Xiaoping.    State Key Laboratory of Mesoscopic Physics, Department of Physics,  Peking University,  Beijing,  Peop. Rep. China.    Gongneng Cailiao  (1999),  30(1),  94-96.  CODEN: GOCAEA  ISSN: 1001-9731.  Journal  written in Chinese.    CAN 130:273613    AN 1999:225001    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

The surface modified PET were prepd. by treating PET film with CF4/CH4 plasmas, and the surface structure, properties and the dynamic behaviors immersed into water of the modified PET were studied by XPS technique.  The results showed that the structures of the modified layers on PET surface depended on the molar ratio of CF4/CH4 feed.  The homogeneous, crosslinking polymd. films were obsd. after treated by CH4/CF4 plasmas, and the fluoride groups appeared on the surface of PET when treated by pure CF4 plasma.  The immersing expts. of the modified PET showed that the layer modified by CF4/CH4 plasmas had stronger hydrophobicity than that of CF4 plasmas alone.

Bibliographic Information

An XPS investigation of thermal degradation and charring in combustion of PVC and PVC/Cu2O/MoO3-the synergy between MoO3 and Cu2O in PVC.     Wang, Jianqi; Li, Bin.    National Laboratory of Flame Retardant Materials, School of Chemical Engineering and Materials Science,  Beijing Institute of Technology,  Beijing,  Peop. Rep. China.    Polymer Degradation and Stability  (1999),  63(2),  279-285.  CODEN: PDSTDW  ISSN: 0141-3910.  Journal  written in English.    CAN 130:282767    AN 1999:161755    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

In addn. to the NBS smoke box and Goodrich smoke-char tester, the present paper shows that the cone calorimeter, due to its multifunctional capability, is one of the effective facilities for the characterization of the smoke-reducing synergism between MoO3 and Cu2O for rigid PVC.  In combination with XPS techniques further information about the charring requisite to the better understanding of charring and smoke emission has been obtained.  The current XPS data were of vital importance in the assessment of the extent of crosslinking of PVC and systems of PVC/transition metals on heating.  It was found that besides char residue percentage, the rate of crosslinking (ROC) derived from C1s spectra at the temp. of LTGRL is a parameter qualified to be a measure for the rate of charring in polymeric matrixes.  The data acquired from XPS/CONE have been harnessed to seek the smoke-reducing synergy between MoO3 and Cu2O for rigid PVC.

Bibliographic Information

Present status of flame-retardant polyamides.     Li, Ying; Wang, Jianqi.    National Laboratory of Flame Retardant Materials,  School of Chemical Engineering and Materials Science Beijing Institute of Technology,  Beijin,  Peop. Rep. China.    Gaofenzi Cailiao Kexue Yu Gongcheng  (1999),  15(1),  18-22,28.  CODEN: GCKGEI  ISSN: 1000-7555.  Journal; General Review  written in Chinese.    CAN 130:282681    AN 1999:149608    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

A review with 14 refs. on flame retardants for polyamides, their flame-retardant performance and action mechanism.

Bibliographic Information

Surface modification of PTFE by ethanol plasma.     Xiaodong, Chen; Hu, Yuanjie; Sun, Ruihuan; Wang, Jianqi.    China Rehabilitation Research Center,  Beijing,  Peop. Rep. China.    Fushe Yanjiu Yu Fushe Gongyi Xuebao  (1998),  16(4),  209-212.  CODEN: FYYXEA  ISSN: 1000-3436.  Journal  written in Chinese.    CAN 130:183131    AN 1998:810609    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

Surface modification of PTFE by ethanol plasma was studied by XPS and contact angle measurement.  The surface hydrophilicity of PTFE was well improved due to the formation of carbon- and oxygen-contg. coating layer after plasma modification.  A good surface dynamics characteristic was obsd. and the improved surface hydrophilicity could be maintained for a long period (over 50 days).

Bibliographic Information

Surface modification of PET by fluorocarbon plasma and the relationship between the sampling depth of XPS and contact angle.     Zhang, Liang; Wang, Jianqi.    Mesoscopic Physics Engineering and Materials Science,  Beijing Institute of Technology,  Beijing,  Peop. Rep. China.    Gaofenzi Xuebao  (1998),   (5),  599-602.  CODEN: GAXUE9  ISSN: 1000-3304.  Journal  written in Chinese.    CAN 130:25688    AN 1998:757270    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

The PET surfaces were modified by fluorocarbon plasma.  Angle-dependent XPS and contact angle techniques were employed to det. the change of the surface structures and properties of the modified PET.  The modified surfaces are more hydrophobic, and CF4/CH4 plasma exhibits more stronger hydrophobic effect than CF4 plasma alone.  The structures and properties of the modified PET surface depend on the molar ratio of the CH4/CF4 feed.  The plots of contact angle vs. molar ratio of the CH4/CF4 feed is the same as that of F/C ratio measured by angle-dependent XPS at 10 degree of taking-off angle.  By comparison, the relationship of the sampling depth of XPS and contact angle can be obtained.

Bibliographic Information

Influence of physical parameters of RF plasma discharge on PET surface modification.     Zhang, Liang; Wang, Jianqi; Zhang, Xinsheng.    State Key Laboratory of Mesoscopic Physics, Department of Physics,  Peking University,  Beijing,  Peop. Rep. China.    Zhenkong Kexue Yu Jishu  (1998),  18(5),  373-376.  CODEN: CKKSDV  ISSN: 0253-9748.  Journal  written in Chinese.    CAN 130:154273    AN 1998:751448    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

PET surface was modified by radio frequency plasma such as oxygen, CF4, and CH4-CF4 plasma.  The influence of various plasma discharge parameters, including discharge time, discharge power, electrode sepn., and complex parameters (energy absorbed by the monomer per unit wt. Gj/kg) on the PET surface modification was studied.  CH4-CF4 plasma resulted in the formation and growth of polymd. layers on PET surfaces, oxygen plasma and pure CF4 plasma etched PET surface.  The increase of the plasma discharge powder and discharge time strongly enhanced the polymn. and/or surface etching.  The increase of electrode sepn. and complex parameter reduced the polymn. and/or surface etching.

Bibliographic Information

Utilization of CONE calorimeter for the appraisal of the flammability and flame retardancy of polymeric materials.     Li, Bin; Wang, Jianqi.    Natl. Flame Retardard Mater. Lab. Sch. Chem. Eng.,  Mater. Sci. Beijing Inst. Technol.,  Beijing,  Peop. Rep. China.    Gaofenzi Cailiao Kexue Yu Gongcheng  (1998),  14(5),  15-19.  CODEN: GCKGEI  ISSN: 1000-7555.  Journal  written in Chinese.    CAN 129:316854    AN 1998:666250    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

A new generation CONE Calorimeter for evaluating flammability and flame retardancy of polymeric materials based on the oxygen consumption principle was introduced.  A no. of other functions were included, such as heat release rate (HRR), effective heat of combustion (EHC), ignitability, smoke/soot and toxic gases, etc.  The studies of mechanism and evaluation of polymer flame retardancy and emission of smoke, etc. by CONE were discussed.

Bibliographic Information

Magnetic characteristics and their paleoclimatic significance of Fengzhou loess in Qinling Mountains, China.     Lei, Xiangyi; Yue, Leping; Wang, Jianqi; Zhang, Li.    Department of Geology,  Northwest University,  Xian,  Peop. Rep. China.    Chinese Science Bulletin  (1998),  43(18),  1571-1575.  CODEN: CSBUEF  ISSN: 1001-6538.  Journal  written in English.    CAN 129:318916    AN 1998:646026    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

The Fengzhou loess section is very typical in the Qinling Mountains.  The section, about 82 m thick and underlain by the Neogene red clay, consists of 33 layers of loess and 33 layers of paleosol.  The section covers Brunhes normal polarity zone and Matuyama reversed polarity zone, and the B/M boundary is located in the middle of L8.  Matuyama reversed polarity zone records Jaramillo, Olduvai and Reunion normal polarity subchrons.  The boundary between Matuyama reversed polarity zone and Gauss normal polarity zone (M/Ga) appears in the lithol. boundary between loess and the Neogene red clay.  Loess accumulation in Fengzhou started before 2.48 Ma.  The magnetic susceptibility curve indicates 33 cold-dry and humid-warm cycles of paleoclimatic variation in the Qinling Mountains during the last 2.48 Ma.  The above climatic fluctuation may be well compared with that of the oxygen isotopic records from deep-sea deposits.

Bibliographic Information

Effect of magnetic field on the surface modification of PET modified by CF4 and CF4/CH4 plasmas. (I).     Zhang, Liang; Wang, Yu; Wang, Jianqi; Hu, Jianfang.    Mesoscopic Phys. Lab., Phys. Dep.,  Peking Univ.,  Beijing,  Peop. Rep. China.    Jilin Daxue Ziran Kexue Xuebao  (1998),   (3),  64-67.  CODEN: CLTTDI  ISSN: 0529-0279.  Journal  written in Chinese.    CAN 129:290764    AN 1998:596967    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract

PET [poly(ethylene terephthalate)] surfaces were modified by CF4 and CH4/CF4 plasmas in the presence of an external magnetic field.  The angle-dependent XPS technique was employed to study the changes of the surface properties of the modified PET.  Homogeneous polymd. films by CH4/CF4 mixt. plasma can be obtained; however, the pure CF4 plasma can not.  Because of the enhancement effects of the magnetic field, the transformation from polymn. to etching occurred, and the turning point shifted to the left.  The characteristics, relative to the different reaction mechanism of the different zone, of the different zone of CH4/CF4 molar ratio were enhanced.

Bibliographic Information

Comparative study of the effect of Cu2O and MoO3 on flame retardance and smoke emission of PVC by cone and TGA.     Li, Bin; Wang, Jianqi.    Dep. Chem.,  Northeast Forestry Univ.,  Harbin,  Peop. Rep. China.    Chinese Science Bulletin  (1998),  43(13),  1090-1094.  CODEN: CSBUEF  ISSN: 1001-6538.  Journal  written in English.    CAN 129:217326    AN 1998:472240    CAPLUS   (Copyright 2004 ACS on SciFinder (R)) 

Abstract 

Cuprous and molybdic oxides exhibit effectiveness in smoke suppression for PVC.  However, few are the data reported concerning flame retardance and smoke emission of PVC taken from cone calorimetry relative to the conventional thermal anal. technique.  Abundant data from cone calorimetry have been acquired.  Data anal. was achieved through the study of MLR, HRR, SEA tested at irradiance of 25 kWM-2.  The understandable flame retardance of PVC/Cu2O and PVC/MoO3 relative to pure PVC has been rationalized by their lowered heat release rates and enhanced char residues.  The difference in smoke redn. between these two oxides consists in the time scale.  As clearly seen under air atm., both oxides exert themselves to the afterglow which has been recognized as a dangerous source, in particular in the full-scale fire situation.

上一页  [1] [2] [3] [4] [5] [6] [7] [8]  下一页