Pub Date : 2008-11-28DOI: 10.2174/1874343900802010058
M. C. Miras, D. Acevedo, N. Monge, E. Frontera, C. Rivarola, C. Barbero
The use of organic chemistry reactions to introduce additional functional groups on polyanilines is described. Among the reactions discussed are: electrophilic aromatic substitution, nucleophilic addition to the aromatic rings, nu- cleophilic substitution on the amine groups and reactions on pendant groups. The use of combinatorial chemistry tech- niques, by coupling of combinatorially synthesised diazonium salts with polyaniline, to produce a functionalized polyani- lines library is also reviewed. The modification of polyaniline introduces or alters different properties of the materials: solubility, self-doping and redox coupled ion exchange. The tailoring of those properties to technical applications is there- fore examined.
{"title":"Organic Chemistry of Polyanilines: Tailoring Properties to Technological Applications","authors":"M. C. Miras, D. Acevedo, N. Monge, E. Frontera, C. Rivarola, C. Barbero","doi":"10.2174/1874343900802010058","DOIUrl":"https://doi.org/10.2174/1874343900802010058","url":null,"abstract":"The use of organic chemistry reactions to introduce additional functional groups on polyanilines is described. Among the reactions discussed are: electrophilic aromatic substitution, nucleophilic addition to the aromatic rings, nu- cleophilic substitution on the amine groups and reactions on pendant groups. The use of combinatorial chemistry tech- niques, by coupling of combinatorially synthesised diazonium salts with polyaniline, to produce a functionalized polyani- lines library is also reviewed. The modification of polyaniline introduces or alters different properties of the materials: solubility, self-doping and redox coupled ion exchange. The tailoring of those properties to technical applications is there- fore examined.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"41 1","pages":"58-73"},"PeriodicalIF":0.0,"publicationDate":"2008-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78389739","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 : 2008-11-14DOI: 10.2174/1874343900802010054
Araf Saïd Dalil, M. I. Ferrahi, M. Belbachir
The polymerization of oxetan with acetic anhydride catalyzed by Maghnite-H + (Mag-H) in dichloromethan (CH2Cl2) as solvant at 25°C was investigated. The effects of the amounts of Mag-H and acetic anhydride on the polymerization of oxetan were studied. The polymerization yield increased as the proportions of catalyst and acetic an- hydride were increased. The reactions were monitored by gel permeation chromatography and 1 H-NMR spectroscopy.
{"title":"Cationic Polymerization of Oxetan by an Acid Exchanged Montmorillonite Clay in the Presence of Acetic Anhydride","authors":"Araf Saïd Dalil, M. I. Ferrahi, M. Belbachir","doi":"10.2174/1874343900802010054","DOIUrl":"https://doi.org/10.2174/1874343900802010054","url":null,"abstract":"The polymerization of oxetan with acetic anhydride catalyzed by Maghnite-H + (Mag-H) in dichloromethan (CH2Cl2) as solvant at 25°C was investigated. The effects of the amounts of Mag-H and acetic anhydride on the polymerization of oxetan were studied. The polymerization yield increased as the proportions of catalyst and acetic an- hydride were increased. The reactions were monitored by gel permeation chromatography and 1 H-NMR spectroscopy.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"80 1","pages":"54-57"},"PeriodicalIF":0.0,"publicationDate":"2008-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83944639","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 : 2008-11-12DOI: 10.2174/1874343900802010043
Trishul Artham, M. Sudhakar, M. Doble, V. Umadevi, R. Viduthalai, K. Kumar, P. S. Murthy, R. Venkatesan
The effect of biofouling on physical, chemical and mechanical changes of Bisphenol A polycarbonate im- mersed at a depth of three meters at two different locations (Port and FSI, Chennai, India) in the Bay of Bengal Sea over a period of six months was the subject of this study. Biofouling in terms of total suspended solids, organic matter and total viable count was higher at Port than at FSI, probably because of higher dissolved oxygen at the former than at the latter site. An increase in glass transition temperature (from 133°C to 147 and 144°C at Port and FSI respectively) was observed in the samples indicating loss of amorphous region and conformational change in the polymer. A two fold decrease in ten- sile strength, a 33% decrease in contact angle and, a reduction in the tertiary methyl and carbonate carbonyl indices were observed. These findings indicate that polycarbonate undergoes a combination of biodeterioration and biodegradation un- der these conditions.
{"title":"Effect of Biofouling on Stability of Polycarbonate in Tropical Seawater","authors":"Trishul Artham, M. Sudhakar, M. Doble, V. Umadevi, R. Viduthalai, K. Kumar, P. S. Murthy, R. Venkatesan","doi":"10.2174/1874343900802010043","DOIUrl":"https://doi.org/10.2174/1874343900802010043","url":null,"abstract":"The effect of biofouling on physical, chemical and mechanical changes of Bisphenol A polycarbonate im- mersed at a depth of three meters at two different locations (Port and FSI, Chennai, India) in the Bay of Bengal Sea over a period of six months was the subject of this study. Biofouling in terms of total suspended solids, organic matter and total viable count was higher at Port than at FSI, probably because of higher dissolved oxygen at the former than at the latter site. An increase in glass transition temperature (from 133°C to 147 and 144°C at Port and FSI respectively) was observed in the samples indicating loss of amorphous region and conformational change in the polymer. A two fold decrease in ten- sile strength, a 33% decrease in contact angle and, a reduction in the tertiary methyl and carbonate carbonyl indices were observed. These findings indicate that polycarbonate undergoes a combination of biodeterioration and biodegradation un- der these conditions.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"2 1","pages":"43-53"},"PeriodicalIF":0.0,"publicationDate":"2008-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82529561","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 : 2008-11-07DOI: 10.2174/1874343900802010038
Gamze Bulut, Asgar Kayan
Tin and titanium pentenoate have been prepared from tin(IV) butoxide and titanium (IV) isopropoxide in alcohol and 3-pentenoic acid. Reactions of Sn(OBu n )4 and Ti(OPr i )4 with 3-pentenoic acid in 1:1 molar ratio were studied in butanol and propanol solution at room temperature by sol-gel process. The complexations were investigated by 13 C, 1 H- NMR and FT-IR spectroscopy. 13 C{ 1 H}, 1 H-NMR and FT-IR spectra showed that 3-pentenoic acid completely reacted with Sn(OBu n )4 and Ti(OPr i )4. These new products were hydrolyzed by water in ratio of 1:4 (M(OR)4 /H2O, M: Sn, Ti, R: butyl and isopropyl). The stability of hydrolyzed products was investigated by 13 C, 1 H NMR and FT-IR. After hydrolysis, it was seen that no 3-pentenoic acid was released from (Ti(OPr i )3(PA))n and but was released from (Sn(OBu n )3(PA))n un- der the studied conditions.
{"title":"Spectroscopic Investigation on the Reactions of Tin and Titanium Alkoxides with 3-Pentenoic Acid","authors":"Gamze Bulut, Asgar Kayan","doi":"10.2174/1874343900802010038","DOIUrl":"https://doi.org/10.2174/1874343900802010038","url":null,"abstract":"Tin and titanium pentenoate have been prepared from tin(IV) butoxide and titanium (IV) isopropoxide in alcohol and 3-pentenoic acid. Reactions of Sn(OBu n )4 and Ti(OPr i )4 with 3-pentenoic acid in 1:1 molar ratio were studied in butanol and propanol solution at room temperature by sol-gel process. The complexations were investigated by 13 C, 1 H- NMR and FT-IR spectroscopy. 13 C{ 1 H}, 1 H-NMR and FT-IR spectra showed that 3-pentenoic acid completely reacted with Sn(OBu n )4 and Ti(OPr i )4. These new products were hydrolyzed by water in ratio of 1:4 (M(OR)4 /H2O, M: Sn, Ti, R: butyl and isopropyl). The stability of hydrolyzed products was investigated by 13 C, 1 H NMR and FT-IR. After hydrolysis, it was seen that no 3-pentenoic acid was released from (Ti(OPr i )3(PA))n and but was released from (Sn(OBu n )3(PA))n un- der the studied conditions.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"2015 1","pages":"38-42"},"PeriodicalIF":0.0,"publicationDate":"2008-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73459488","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 : 2008-10-23DOI: 10.2174/1874343900802010032
Joel Vargas, Serguei Fomine, L. Fomina, M. Tlenkopatchev
Ring-opening metathesis polymerization (ROMP) of norbornene (NB) and its derivatives N-adamantyl-exo- endo-norbornene-5,6-dicarboximide (AdNDI) and N-cyclohexyl-exo-endo-norbornene-5,6-dicarboximide (CyNDI) in the presence of cis-1,4-dichloro-2-butene (2a) and cis-1,2-dichloro-ethylene (2b) as chain transfer agents (CTAs) using a (1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazolilydene) (PCy3)Cl2Ru=CHPh (I) has been studied. � Halogenated ole- fin 2b shows no activity as a CTA whenhalogenated olefin 2a is readily cross-metathesized with NB and norbornene dicarboximides. The chain transfer reaction pathways during the ROMP of NB to 2b using a (1,3-diphenyl-4,5- dihydroimidazol-2-ylidene) (PCy3)Cl2Ru=CHPh (1) have been studied at B3LYP/LACVP* level of theory. The calcula- tions show that 2b is a poor substrate for the metathesis reaction due to the steric effect produced by chlorine atoms di- rectly linked to the double bond. The calculated Gibbs free activation energy of a chain transfer reaction from ring-opened NB to 2b was 25.1 kcal/mol.
{"title":"Halogenated Olefins as Chain Transfer Agents in the Synthesis of Telechelic Polynorbornenes Using Ruthenium Alkylidene Catalysts. Computational and Experimental Studies","authors":"Joel Vargas, Serguei Fomine, L. Fomina, M. Tlenkopatchev","doi":"10.2174/1874343900802010032","DOIUrl":"https://doi.org/10.2174/1874343900802010032","url":null,"abstract":"Ring-opening metathesis polymerization (ROMP) of norbornene (NB) and its derivatives N-adamantyl-exo- endo-norbornene-5,6-dicarboximide (AdNDI) and N-cyclohexyl-exo-endo-norbornene-5,6-dicarboximide (CyNDI) in the presence of cis-1,4-dichloro-2-butene (2a) and cis-1,2-dichloro-ethylene (2b) as chain transfer agents (CTAs) using a (1,3-bis(2,4,6-trimethylphenyl)-4,5-dihydroimidazolilydene) (PCy3)Cl2Ru=CHPh (I) has been studied. � Halogenated ole- fin 2b shows no activity as a CTA whenhalogenated olefin 2a is readily cross-metathesized with NB and norbornene dicarboximides. The chain transfer reaction pathways during the ROMP of NB to 2b using a (1,3-diphenyl-4,5- dihydroimidazol-2-ylidene) (PCy3)Cl2Ru=CHPh (1) have been studied at B3LYP/LACVP* level of theory. The calcula- tions show that 2b is a poor substrate for the metathesis reaction due to the steric effect produced by chlorine atoms di- rectly linked to the double bond. The calculated Gibbs free activation energy of a chain transfer reaction from ring-opened NB to 2b was 25.1 kcal/mol.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"33 1","pages":"32-37"},"PeriodicalIF":0.0,"publicationDate":"2008-10-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86603685","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 : 2008-06-27DOI: 10.2174/1874343900802010026
L. Nita, A. Chiriac, S. Cimmino, C. Silvestre, D. Duraccio, C. Vasile
The paper evidences changes of thermal properties of poly(methyl methacrylate) as well as methyl methacry- late copolymers with glycidyl methacrylate (GMA) polymers synthesized classic and comparatively in a magnetic field. Samples of poly(methyl methacrylate) and methyl methacrylate copolymers with different amounts of GMA synthesized by radical emulsion polymerization with or without the presence of a continuous electro- magnetic field, they were thus compared. The thermal behavior was studied by Differential Scanning Calorimetry (DSC) and Thermogravimetry (TGA). The paper evidences the higher Tg as well as the higher thermal stability of the macromolecular chains structures synthe- sized in the presence of the electromagnetic field. analysis (TGA), were identified using a mass spectrometer attached to the TGA apparatus. They concluded that the presence of the second monomer (GMA) favors combination reactions rather than disproportionation as termination step. Thus, the copolymers degradation occurs only at high tem- peratures at which the polymers that have no terminal un- saturation degrade. This involves random scission followed by depropagation.
{"title":"Polymerization in Magnetic Field. XIX. Thermal Behavior of the Copolymers of Methyl Methacrylate with Glycidyl Methacrylate Synthesized in the Magnetic Field Presence","authors":"L. Nita, A. Chiriac, S. Cimmino, C. Silvestre, D. Duraccio, C. Vasile","doi":"10.2174/1874343900802010026","DOIUrl":"https://doi.org/10.2174/1874343900802010026","url":null,"abstract":"The paper evidences changes of thermal properties of poly(methyl methacrylate) as well as methyl methacry- late copolymers with glycidyl methacrylate (GMA) polymers synthesized classic and comparatively in a magnetic field. Samples of poly(methyl methacrylate) and methyl methacrylate copolymers with different amounts of GMA synthesized by radical emulsion polymerization with or without the presence of a continuous electro- magnetic field, they were thus compared. The thermal behavior was studied by Differential Scanning Calorimetry (DSC) and Thermogravimetry (TGA). The paper evidences the higher Tg as well as the higher thermal stability of the macromolecular chains structures synthe- sized in the presence of the electromagnetic field. analysis (TGA), were identified using a mass spectrometer attached to the TGA apparatus. They concluded that the presence of the second monomer (GMA) favors combination reactions rather than disproportionation as termination step. Thus, the copolymers degradation occurs only at high tem- peratures at which the polymers that have no terminal un- saturation degrade. This involves random scission followed by depropagation.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"1 1","pages":"26-31"},"PeriodicalIF":0.0,"publicationDate":"2008-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82368213","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 : 2008-06-27DOI: 10.2174/1874343900802010019
S. Vega-Díaz, F. Medellín-Rodríguez, S. Sánchez-Valdes, B. Handy, J. M. Mata-Padilla, O. Dávalos-Montoya
The synthesis and morphological characterization of Nylon 6 hybrids using the most common montmorillonite types, sodium and calcium, are reported. Two local nanoclays and a commercial, cation exchanged, reference were used in order to obtain the hybrid products. The local sodium and calcium nanoclays were first homoionized and then ion ex- changed with surfactants, being the main purpose to obtain similar reaction precursors as the commercial clay. Both local clay precursors and commercial clay showed similar crystallographic structure and layer-to-layer spacing after all phys- icochemical treatments. The best reaction conditions were first determined and then a simple infra-red based technique was implemented with the purpose to obtain the molecular weight of the hybrid products. It was determined that, sodium, calcium, and commercial nanoclays render relatively similar molecular weights of nanoclay hybrids using identical syn- thesis conditions. Thermal analyses indicated the formation of two and three melting endotherms in all cases depending on the isothermal crystallization temperature. X-ray diffraction patterns displayed crystal plane truncation which is usually observed in nanoclay hybrids. Plane truncation depended on the nanoclays nature, although the highest truncation was ob- served with commercial and sodium nanoclays. X-rays dispersion results allowed to infer the partial formation of non- hybrid polymer depending on the type of clay, sodium nanoclay showing the lesser proportion, and as a consequence the highest hybridization. Transmission electron microscopy results corroborated the relative degree of exfoliation and nano- clay dispersion of the hybrid products.
{"title":"Synthesis and Morphological Characterization of Sodium and Calcium Clay Nanostructured Poly(ε-Caprolactam) [Nylon 6] Hybrids","authors":"S. Vega-Díaz, F. Medellín-Rodríguez, S. Sánchez-Valdes, B. Handy, J. M. Mata-Padilla, O. Dávalos-Montoya","doi":"10.2174/1874343900802010019","DOIUrl":"https://doi.org/10.2174/1874343900802010019","url":null,"abstract":"The synthesis and morphological characterization of Nylon 6 hybrids using the most common montmorillonite types, sodium and calcium, are reported. Two local nanoclays and a commercial, cation exchanged, reference were used in order to obtain the hybrid products. The local sodium and calcium nanoclays were first homoionized and then ion ex- changed with surfactants, being the main purpose to obtain similar reaction precursors as the commercial clay. Both local clay precursors and commercial clay showed similar crystallographic structure and layer-to-layer spacing after all phys- icochemical treatments. The best reaction conditions were first determined and then a simple infra-red based technique was implemented with the purpose to obtain the molecular weight of the hybrid products. It was determined that, sodium, calcium, and commercial nanoclays render relatively similar molecular weights of nanoclay hybrids using identical syn- thesis conditions. Thermal analyses indicated the formation of two and three melting endotherms in all cases depending on the isothermal crystallization temperature. X-ray diffraction patterns displayed crystal plane truncation which is usually observed in nanoclay hybrids. Plane truncation depended on the nanoclays nature, although the highest truncation was ob- served with commercial and sodium nanoclays. X-rays dispersion results allowed to infer the partial formation of non- hybrid polymer depending on the type of clay, sodium nanoclay showing the lesser proportion, and as a consequence the highest hybridization. Transmission electron microscopy results corroborated the relative degree of exfoliation and nano- clay dispersion of the hybrid products.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"91 1","pages":"19-25"},"PeriodicalIF":0.0,"publicationDate":"2008-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83095957","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 : 2008-06-13DOI: 10.2174/1874343900802010006
C. C. Ruiz, J. Hierrezuelo, J. M. Peula-García, J. Aguiar
{"title":"Interaction Between n-octyl-β-D-thioglucopyranoside and Bovine Serum Albumin~!2008-04-22~!2008-05-06~!2008-06-12~!","authors":"C. C. Ruiz, J. Hierrezuelo, J. M. Peula-García, J. Aguiar","doi":"10.2174/1874343900802010006","DOIUrl":"https://doi.org/10.2174/1874343900802010006","url":null,"abstract":"","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"1 1","pages":"6-18"},"PeriodicalIF":0.0,"publicationDate":"2008-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84954158","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 : 2008-03-04DOI: 10.2174/1874343900802010001
M. Fares
Two revisited mathematical kinetic relationships were derived, evaluated and applied on linear polymers such as polystyrene and copolymers such as (NIPAAm-alt-HEMA) and (MAAm-alt-HEMA) copolymers respectively. The va- lidity of these equations was successfully verified. The first relationship, equation 12, interrelates exponentially kinetic chain length, average molecular weight and degree of polymerization of linear polymers with different temperatures. Fur- thermore; equation 12 could novelly define the rate of polymerization (Rp) and consequently the overall activation energy ( E) of the polymerization process could be determined. The second derived relationship interrelates the reactivity ratio product (r1r2) of two monomers interacting with each other, with different temperature. Application of equation 16 could determine the behavioral sequence of monomer 1 toward monomer 2 in the copolymerization process. The value of (E12+E21) (E11+E22) could result with the determination of type of copolymers formed. The reactivity ratio values for (NIPAAm-alt-HEMA) and (MAAm-alt-HEMA) copolymers were determined using Kelen-Tudos technique.
{"title":"Revisited Kinetic Chain Length and Reactivity Ratio Approaches for Linear Polymers and Copolymers","authors":"M. Fares","doi":"10.2174/1874343900802010001","DOIUrl":"https://doi.org/10.2174/1874343900802010001","url":null,"abstract":"Two revisited mathematical kinetic relationships were derived, evaluated and applied on linear polymers such as polystyrene and copolymers such as (NIPAAm-alt-HEMA) and (MAAm-alt-HEMA) copolymers respectively. The va- lidity of these equations was successfully verified. The first relationship, equation 12, interrelates exponentially kinetic chain length, average molecular weight and degree of polymerization of linear polymers with different temperatures. Fur- thermore; equation 12 could novelly define the rate of polymerization (Rp) and consequently the overall activation energy ( E) of the polymerization process could be determined. The second derived relationship interrelates the reactivity ratio product (r1r2) of two monomers interacting with each other, with different temperature. Application of equation 16 could determine the behavioral sequence of monomer 1 toward monomer 2 in the copolymerization process. The value of (E12+E21) (E11+E22) could result with the determination of type of copolymers formed. The reactivity ratio values for (NIPAAm-alt-HEMA) and (MAAm-alt-HEMA) copolymers were determined using Kelen-Tudos technique.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"144 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2008-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86204662","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 : 2007-12-07DOI: 10.2174/1874343900701010001
O. Coulembier, Cécile Delcourt, P. Dubois
The ring-opening polymerization (ROP) of L,L-lactide (L-LA) has been studied in bulk using alcohol (either methanol or benzyl alcohol) and 1,3,4-triphenyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene carbene, 1, respectively as initiator and non-organometallic catalyst, over a range of temperature and alcohol-to-1 molar ratios. Although 1 is known to perfectly control the polymerization of L-LA in solution at 90°C, its efficiency in bulk is drastically decreased since its thermal instability limits the possibility to reach high molecular weight poly(L-lactide) (PL-LA). Under optimum conditions, PL-LA chains with average molecular weight up to 10,000 g.mol have been obtained within 15 minutes and interestingly characterized by very narrow polydispersity indices. Compared to PL-LA conventionally prepared with stannous octoate as catalyst, the thermal stability proved remarkably enhanced when the ROP was promoted by 1.
{"title":"Bulk Polymerization of (L,L)-Lactide Using Non-Organometallic Triazolium Carbene: Limited Advantages","authors":"O. Coulembier, Cécile Delcourt, P. Dubois","doi":"10.2174/1874343900701010001","DOIUrl":"https://doi.org/10.2174/1874343900701010001","url":null,"abstract":"The ring-opening polymerization (ROP) of L,L-lactide (L-LA) has been studied in bulk using alcohol (either methanol or benzyl alcohol) and 1,3,4-triphenyl-4,5-dihydro-1H-1,2,4-triazol-5-ylidene carbene, 1, respectively as initiator and non-organometallic catalyst, over a range of temperature and alcohol-to-1 molar ratios. Although 1 is known to perfectly control the polymerization of L-LA in solution at 90°C, its efficiency in bulk is drastically decreased since its thermal instability limits the possibility to reach high molecular weight poly(L-lactide) (PL-LA). Under optimum conditions, PL-LA chains with average molecular weight up to 10,000 g.mol have been obtained within 15 minutes and interestingly characterized by very narrow polydispersity indices. Compared to PL-LA conventionally prepared with stannous octoate as catalyst, the thermal stability proved remarkably enhanced when the ROP was promoted by 1.","PeriodicalId":22718,"journal":{"name":"The Open Macromolecules Journal","volume":"413 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2007-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79975853","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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