Pub Date : 2010-05-04DOI: 10.2174/1874343901004010015
M. L. Lorenzo
The thermal properties of cis-1,4-polybutadiene (cis-PBD) were investigated in dependence of content of cis units and of linearity of the main chain. cis-PBD grades containing a fraction of cis-segments ranging from 93 to 98 %, and with linear or branched chains, were analyzed. Upon isothermal crystallization from the melt at -26 °C for 1 h, followed by cooling to below the glass transition temperature, cis-PBD develops a three-phase structure, where the mobile amorphous phase is equal to 0.41, independently of chain structure, crystallinity ranges from 0.23 to 0.28, and the rigid amorphous fraction varies from 0.31 to 0.35. Up to three main endotherms can be evidenced by calorimetry at slow heating rate, depending on chain regularity. The multiple melting behavior was discussed on the basis of the three-phase structure, as well as of crystallization kinetics.
{"title":"Thermal Properties and Three-Phase Structure of cis-1,4-Polybutadiene~!2009-11-20~!2009-12-15~!2010-04-20~!","authors":"M. L. Lorenzo","doi":"10.2174/1874343901004010015","DOIUrl":"https://doi.org/10.2174/1874343901004010015","url":null,"abstract":"The thermal properties of cis-1,4-polybutadiene (cis-PBD) were investigated in dependence of content of cis units and of linearity of the main chain. cis-PBD grades containing a fraction of cis-segments ranging from 93 to 98 %, and with linear or branched chains, were analyzed. Upon isothermal crystallization from the melt at -26 °C for 1 h, followed by cooling to below the glass transition temperature, cis-PBD develops a three-phase structure, where the mobile amorphous phase is equal to 0.41, independently of chain structure, crystallinity ranges from 0.23 to 0.28, and the rigid amorphous fraction varies from 0.31 to 0.35. Up to three main endotherms can be evidenced by calorimetry at slow heating rate, depending on chain regularity. The multiple melting behavior was discussed on the basis of the three-phase structure, as well as of crystallization kinetics.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"331 1","pages":"15-21"},"PeriodicalIF":0.0,"publicationDate":"2010-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73863126","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2010-01-27DOI: 10.2174/1874343901004010001
J. Qian, Cun-Yue Guo
This mini-review article addresses the development in synthesizing polyolefin/clay nanocomposites by olefin polymerization under catalysis of clay intercalated precatalysts in recent years. The review comprises three parts which focus on mainly the synthetic route, structural characterization, and properties of polyolefin/clay nanocomposites, respec- tively. Moreover, outlook for future research and development trends is outlined.
{"title":"Polyolefin-Clay Nanocomposites from Olefin Polymerization between Clay Layers","authors":"J. Qian, Cun-Yue Guo","doi":"10.2174/1874343901004010001","DOIUrl":"https://doi.org/10.2174/1874343901004010001","url":null,"abstract":"This mini-review article addresses the development in synthesizing polyolefin/clay nanocomposites by olefin polymerization under catalysis of clay intercalated precatalysts in recent years. The review comprises three parts which focus on mainly the synthetic route, structural characterization, and properties of polyolefin/clay nanocomposites, respec- tively. Moreover, outlook for future research and development trends is outlined.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"107 1","pages":"1-14"},"PeriodicalIF":0.0,"publicationDate":"2010-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76238710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-10-23DOI: 10.2174/1874343900903010041
J. Maláč
Mooney viscosity and Mooney relaxation of unaged and oven aged SMR L natural rubber samples were stud- ied. The viscosity was characterized by ML (1+4) 100°C and the rate of stress relaxation by the exponent a in a power law M = k (t) a . With the increasing time of oven aging at 140°C the decrease of both viscosity and stress relaxation rate expo- nent were observed. Aging of raw natural rubber can therefore be studied by Mooney viscosity and Mooney relaxation tests and obtained results are sensitive enough to be used for characterization of raw natural rubber stability.
研究了未老化和烘箱老化SMR - L天然橡胶试样的穆尼粘度和穆尼弛豫。粘度表征为ML(1+4) 100°C，应力松弛率表征为幂律M = k (t) a的指数a。随着140℃高温时效时间的延长，黏度和应力松弛率均呈下降趋势。因此，可以通过穆尼粘度和穆尼松弛试验来研究天然生胶的老化，所得结果足够灵敏，可用于表征天然生胶的稳定性。
{"title":"Viscosity, Relaxation and Stability of Natural Rubber","authors":"J. Maláč","doi":"10.2174/1874343900903010041","DOIUrl":"https://doi.org/10.2174/1874343900903010041","url":null,"abstract":"Mooney viscosity and Mooney relaxation of unaged and oven aged SMR L natural rubber samples were stud- ied. The viscosity was characterized by ML (1+4) 100°C and the rate of stress relaxation by the exponent a in a power law M = k (t) a . With the increasing time of oven aging at 140°C the decrease of both viscosity and stress relaxation rate expo- nent were observed. Aging of raw natural rubber can therefore be studied by Mooney viscosity and Mooney relaxation tests and obtained results are sensitive enough to be used for characterization of raw natural rubber stability.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"81 1","pages":"41-44"},"PeriodicalIF":0.0,"publicationDate":"2009-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80886959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-09-11DOI: 10.2174/1874343900903010027
L. Nita, A. Chiriac, S. Cimmino, C. Silvestre, D. Duraccio, C. Vasile
The thermal behavior of polystyrene (PS) and of styrene copolymers with 2, 3 epoxypropyl methacrylate (GMA) synthesized in the presence of the magnetic field has been studied. The thermal behavior was investigated by thermogravimetry (TGA) and differential scanning calorimetry (DSC) techniques. The synthesized polymeric latexes were also characterized from the view point of the particle size distribution (70-200 nm) as well as of their stability by de- termining the zeta potential values. The decrease of zeta potential absolute value with the increase of GMA content or growth of the temperature it was observed. At the same time, the increase of zeta potential absolute value corresponds to latexes prepared in the MF presence. The presence of the magnetic field during syntheses increases the swelling capaci- ties, glass transition temperature and thermal stability of both homopolymers as well as of the synthesized copolymers. The behavior was attributed to a potential ordered structure induced by the magnetic field during syntheses upon macro- molecular chains.
{"title":"Polymerization in Magnetic Field. XX. Thermal Behavior of the Copolymersof Styrene with 2, 3 Epoxypropyl Methacrylate Synthesized in theMagnetic Field Presence","authors":"L. Nita, A. Chiriac, S. Cimmino, C. Silvestre, D. Duraccio, C. Vasile","doi":"10.2174/1874343900903010027","DOIUrl":"https://doi.org/10.2174/1874343900903010027","url":null,"abstract":"The thermal behavior of polystyrene (PS) and of styrene copolymers with 2, 3 epoxypropyl methacrylate (GMA) synthesized in the presence of the magnetic field has been studied. The thermal behavior was investigated by thermogravimetry (TGA) and differential scanning calorimetry (DSC) techniques. The synthesized polymeric latexes were also characterized from the view point of the particle size distribution (70-200 nm) as well as of their stability by de- termining the zeta potential values. The decrease of zeta potential absolute value with the increase of GMA content or growth of the temperature it was observed. At the same time, the increase of zeta potential absolute value corresponds to latexes prepared in the MF presence. The presence of the magnetic field during syntheses increases the swelling capaci- ties, glass transition temperature and thermal stability of both homopolymers as well as of the synthesized copolymers. The behavior was attributed to a potential ordered structure induced by the magnetic field during syntheses upon macro- molecular chains.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"18 1","pages":"27-36"},"PeriodicalIF":0.0,"publicationDate":"2009-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73502991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-09-07DOI: 10.2174/1874343900903010037
M. Duhovic, P. Maitrot, S. Fakirov
Exploring the polymorphism phenomenon of polyamide 66 (PA 66) a single polymer composite (SPC) was prepared. The matrix was obtained via compression molding and quenching in ice water expecting to comprise the modi- fication with lower melting temperature (Tm). The reinforcement was commercial textile yarn of PA 66, characterized by a higher Tm. Layers of the yarn were sandwiched between matrix films and compression molded at 250 °C, i.e. 10 °C below Tm of the reinforcement. SEM observations revealed the layered structure of SPC as well as a good adhesion between the composite components due to surface premelting. The tensile testing showed, as compared with the matrix, an increase of the initial modulus by 28% and of the tensile strength by 160% when the reinforcing component of the SPC amounted to only 20 wt%. Optimization of the preparation conditions, including variation of the matrix/reinforcement ratio as well as trialing of other polyamides, is in progress.
{"title":"Polyamide 66 Polymorphic Single Polymer Composites","authors":"M. Duhovic, P. Maitrot, S. Fakirov","doi":"10.2174/1874343900903010037","DOIUrl":"https://doi.org/10.2174/1874343900903010037","url":null,"abstract":"Exploring the polymorphism phenomenon of polyamide 66 (PA 66) a single polymer composite (SPC) was prepared. The matrix was obtained via compression molding and quenching in ice water expecting to comprise the modi- fication with lower melting temperature (Tm). The reinforcement was commercial textile yarn of PA 66, characterized by a higher Tm. Layers of the yarn were sandwiched between matrix films and compression molded at 250 °C, i.e. 10 °C below Tm of the reinforcement. SEM observations revealed the layered structure of SPC as well as a good adhesion between the composite components due to surface premelting. The tensile testing showed, as compared with the matrix, an increase of the initial modulus by 28% and of the tensile strength by 160% when the reinforcing component of the SPC amounted to only 20 wt%. Optimization of the preparation conditions, including variation of the matrix/reinforcement ratio as well as trialing of other polyamides, is in progress.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"33 1","pages":"37-40"},"PeriodicalIF":0.0,"publicationDate":"2009-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87961335","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-04-16DOI: 10.2174/1874343900903010012
Jiayan Wu, Cuihua Liu, Chao Gao
The competitive host-guest encapsulations of palmityl chloride-modified amphiphilic hyperbranched poly(amido-amine) (HPAMAM-PC) and poly(sulfone-amine) (HPSA-PC) to selected pairs of dyes are reported. Water- soluble and chloroform-insoluble dyes, such as methyl orange (MO), methyl blue (MB), rose bengal (RB), fluorescein so- dium (FSS), eosin Y (EY) and phloxine B (PB), can be transferred from aqueous phase into chloroform phase by the HPAMAM-PC and HPSA-PC. UV/Vis spectra were used to determine the loading capabilities (Cloads) of different dyes in the case of single-dye encapsulations (Exp I). Four pairs of dyes: (1) MO and RB, (2) MO and PB, (3) MO and EY, (4) MO and FSS, were chosen to perform comparative experiments to investigate the influence of competitive interactions on the Cloads of dye pairs. As a result, in the cases of one-step double-dye encapsulations (Exp II) and gradual double-dye en- capsulations (Exp III), we found three kinds of competitive relationships: (1) The Cload of MO decreased significantly in the presence of either RB or PB, compared with the Cload in the single-dye encapsulation, while the existence of MO did not affect the encapsulations to RB and PB greatly, (2) the Cloads of both dyes decreased if they were encapsulated simul- taneously by HPAMAM-PC or HPSA-PC (MO & EY), (3) FSS can hardly be encapsulated by the hyperbranched poly- mers with the existence of MO in the aqueous solution. 1 H NMR, FTIR and thermogravimetric analysis (TGA) were used to confirm the resulting competitive encapsulations. Relatively selective constant to MO (Rdye/MO) was defined to measure the competitive ability of each dye to MO quantitatively. The competitive abilities of RB, PB were larger than that of MO, while EY almost equal to MO and FSS lower than MO. The size of the dye molecules, electrostatic acid-base interactions between the dye molecules and the polymers, the interaction between different dyes were considered to be the main causes of the results.
{"title":"Competitive Supramolecular Encapsulation of Amphiphilic HyperbranchedPolymers Made from A2 and BB’2 Type Monomers. 1. Polyadditionof 1-(2-aminoethyl)piperazine to Divinyl Sulfone","authors":"Jiayan Wu, Cuihua Liu, Chao Gao","doi":"10.2174/1874343900903010012","DOIUrl":"https://doi.org/10.2174/1874343900903010012","url":null,"abstract":"The competitive host-guest encapsulations of palmityl chloride-modified amphiphilic hyperbranched poly(amido-amine) (HPAMAM-PC) and poly(sulfone-amine) (HPSA-PC) to selected pairs of dyes are reported. Water- soluble and chloroform-insoluble dyes, such as methyl orange (MO), methyl blue (MB), rose bengal (RB), fluorescein so- dium (FSS), eosin Y (EY) and phloxine B (PB), can be transferred from aqueous phase into chloroform phase by the HPAMAM-PC and HPSA-PC. UV/Vis spectra were used to determine the loading capabilities (Cloads) of different dyes in the case of single-dye encapsulations (Exp I). Four pairs of dyes: (1) MO and RB, (2) MO and PB, (3) MO and EY, (4) MO and FSS, were chosen to perform comparative experiments to investigate the influence of competitive interactions on the Cloads of dye pairs. As a result, in the cases of one-step double-dye encapsulations (Exp II) and gradual double-dye en- capsulations (Exp III), we found three kinds of competitive relationships: (1) The Cload of MO decreased significantly in the presence of either RB or PB, compared with the Cload in the single-dye encapsulation, while the existence of MO did not affect the encapsulations to RB and PB greatly, (2) the Cloads of both dyes decreased if they were encapsulated simul- taneously by HPAMAM-PC or HPSA-PC (MO & EY), (3) FSS can hardly be encapsulated by the hyperbranched poly- mers with the existence of MO in the aqueous solution. 1 H NMR, FTIR and thermogravimetric analysis (TGA) were used to confirm the resulting competitive encapsulations. Relatively selective constant to MO (Rdye/MO) was defined to measure the competitive ability of each dye to MO quantitatively. The competitive abilities of RB, PB were larger than that of MO, while EY almost equal to MO and FSS lower than MO. The size of the dye molecules, electrostatic acid-base interactions between the dye molecules and the polymers, the interaction between different dyes were considered to be the main causes of the results.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"192 1","pages":"12-26"},"PeriodicalIF":0.0,"publicationDate":"2009-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72772347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-03-06DOI: 10.2174/1874343900903010006
B. Shi, Cun-Yue Guo, Y. Ke, Mingge Zhang, You-liang Hu
PE/MMT nanocomposites containing different amount of MMT were measured for isothermal crystallization. The combination of Ozawa equation and Avrami equation was found applicable in explaining the crystallization behavior of the nanocomposites. In certain range of MMT loadings, MMT particles played the role of nucleating agents that pro- moted the crystallization rate of the polymer matrix, thus making the adjustment of the crystallinity of PE nanocomposites flexible and convenient.
{"title":"Nonisothermal Crystallization Behavior of In-Situ Formed Polyethylene/Montmorillonite (PE/MMT) Nanocomposites Through Ethylene Copolym-erization","authors":"B. Shi, Cun-Yue Guo, Y. Ke, Mingge Zhang, You-liang Hu","doi":"10.2174/1874343900903010006","DOIUrl":"https://doi.org/10.2174/1874343900903010006","url":null,"abstract":"PE/MMT nanocomposites containing different amount of MMT were measured for isothermal crystallization. The combination of Ozawa equation and Avrami equation was found applicable in explaining the crystallization behavior of the nanocomposites. In certain range of MMT loadings, MMT particles played the role of nucleating agents that pro- moted the crystallization rate of the polymer matrix, thus making the adjustment of the crystallinity of PE nanocomposites flexible and convenient.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"6 1 1","pages":"6-11"},"PeriodicalIF":0.0,"publicationDate":"2009-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83609041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-03-06DOI: 10.2174/1874343900903010001
P. Srihanam, W. Simchuer
Two-dimensional silk scaffolds were directly spun on the glass plates by Bombyx mori (called locally Nang- Lai) silkworms and used as subject for proteolytic degradation study with protease XXIII. The silk scaffolds were incu- bated with enzyme solution at 37 °C up to 10 weeks. Those of the scaffold properties: surface morphology, secondary structure, mass loss, degradation ratios and particle sizes were investigated. Silk fibroin scaffolds slightly changed of their structure after exposure to the protease. They were also loose of mass greater than 20% at the end of enzyme incubation periods. Much degradation of the scaffolds was quickly during the 4 weeks and scattering of the particle sizes between 1 to 15 μm were found. The results suggested that protease XXIII is an enzyme which could be degraded of the silk fibroin. Therefore, it will be used this enzyme as model study or for preparing silk material for further applications.
{"title":"Proteolytic Degradation of Silk Fibroin Scaffold by Protease XXIII","authors":"P. Srihanam, W. Simchuer","doi":"10.2174/1874343900903010001","DOIUrl":"https://doi.org/10.2174/1874343900903010001","url":null,"abstract":"Two-dimensional silk scaffolds were directly spun on the glass plates by Bombyx mori (called locally Nang- Lai) silkworms and used as subject for proteolytic degradation study with protease XXIII. The silk scaffolds were incu- bated with enzyme solution at 37 °C up to 10 weeks. Those of the scaffold properties: surface morphology, secondary structure, mass loss, degradation ratios and particle sizes were investigated. Silk fibroin scaffolds slightly changed of their structure after exposure to the protease. They were also loose of mass greater than 20% at the end of enzyme incubation periods. Much degradation of the scaffolds was quickly during the 4 weeks and scattering of the particle sizes between 1 to 15 μm were found. The results suggested that protease XXIII is an enzyme which could be degraded of the silk fibroin. Therefore, it will be used this enzyme as model study or for preparing silk material for further applications.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"46 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2009-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86716081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-01-02DOI: 10.2174/1874343900802010080
F. Li, P. Jiang, Boyue Wu, Rui-rui Sun, Jun Chen, Dongping Liu, L. Zhong, Yanfen Wang
TEM pictures that were taken at different polymerization times during the formation process of the in- tramolecularly cross-linked macromolecule (ICM) indicate that ICM growth undergoes three stages. At the first stage, monomers (i.e. prepolymers) react with each other to form small coils, called "dot molecules" (DM), which are shown as small black dots in TEM pictures. At the second phase, the reaction of functional groups on the surface of DMs produces globular intramolecularly cross-linked macromolecules which are called pre-ICMs. At the third stages, the globular pre- ICMs react with each other to form ICMs. As soon as DMs formed, they aggregate into molecular cluster. DMs are re- stricted within the molecular cluster. This state of aggregation is beneficial to reaction between DMs, since a higher fre- quency of collision can occur in the molecular cluster. In fact, the molecular cluster is the key polymerization site in the controllable cross-linking polymerization system.
{"title":"The Growth Process of the Soluble Cross-Linked Macromolecule of PU","authors":"F. Li, P. Jiang, Boyue Wu, Rui-rui Sun, Jun Chen, Dongping Liu, L. Zhong, Yanfen Wang","doi":"10.2174/1874343900802010080","DOIUrl":"https://doi.org/10.2174/1874343900802010080","url":null,"abstract":"TEM pictures that were taken at different polymerization times during the formation process of the in- tramolecularly cross-linked macromolecule (ICM) indicate that ICM growth undergoes three stages. At the first stage, monomers (i.e. prepolymers) react with each other to form small coils, called \"dot molecules\" (DM), which are shown as small black dots in TEM pictures. At the second phase, the reaction of functional groups on the surface of DMs produces globular intramolecularly cross-linked macromolecules which are called pre-ICMs. At the third stages, the globular pre- ICMs react with each other to form ICMs. As soon as DMs formed, they aggregate into molecular cluster. DMs are re- stricted within the molecular cluster. This state of aggregation is beneficial to reaction between DMs, since a higher fre- quency of collision can occur in the molecular cluster. In fact, the molecular cluster is the key polymerization site in the controllable cross-linking polymerization system.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"12 1","pages":"80-88"},"PeriodicalIF":0.0,"publicationDate":"2009-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84615141","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2009-01-02DOI: 10.2174/1874343900802010074
Manish Taunk, A. Kapil, S. Chand
We report the synthesis of polypyrrole composite films by chemical oxidation polymerization of pyrrole dif- fused inside poly(vinylidene fluoride) matrix and temperature dependant dc conductivity study of these composite films. Ammonium persulfate is used as an oxidizing agent and HCl as the dopant in aqueous medium. This technique produces highly conductive, flexible and free standing polymer composite films in semi-interpenetrating architecture. It is observed that conductivity of the composite films can be controlled by varying the dopant concentration. The variation of conduc- tivity with temperature indicates the semiconducting nature of these composite films. The temperature dependence of conductivity is explained in the light of two different models from which activation energy (Ea) and other hopping pa- rameters are determined. Experimental data fits well with variable range hopping model and three dimensional charge transport mechanism is shown to occur in these films.
{"title":"Synthesis and Electrical Characterization of Self-Supported Conducting Polypyrrole-Poly(vinylidene fluoride) Composite Films","authors":"Manish Taunk, A. Kapil, S. Chand","doi":"10.2174/1874343900802010074","DOIUrl":"https://doi.org/10.2174/1874343900802010074","url":null,"abstract":"We report the synthesis of polypyrrole composite films by chemical oxidation polymerization of pyrrole dif- fused inside poly(vinylidene fluoride) matrix and temperature dependant dc conductivity study of these composite films. Ammonium persulfate is used as an oxidizing agent and HCl as the dopant in aqueous medium. This technique produces highly conductive, flexible and free standing polymer composite films in semi-interpenetrating architecture. It is observed that conductivity of the composite films can be controlled by varying the dopant concentration. The variation of conduc- tivity with temperature indicates the semiconducting nature of these composite films. The temperature dependence of conductivity is explained in the light of two different models from which activation energy (Ea) and other hopping pa- rameters are determined. Experimental data fits well with variable range hopping model and three dimensional charge transport mechanism is shown to occur in these films.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"32 1","pages":"74-79"},"PeriodicalIF":0.0,"publicationDate":"2009-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87894483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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