Acta Polymerica最新文献

{"title":"Grafted carbon fibers and their physico-chemical properties. Part IV: Grafting of cyano-biphenyl containing liquid-crystalline monomers onto modified carbon fibers","authors":"M. Selimović,&nbsp;A. Bismarck,&nbsp;M. Pfaffernoschke,&nbsp;J. Springer","doi":"10.1002/(SICI)1521-4044(19990401)50:4<156::AID-APOL156>3.0.CO;2-5","DOIUrl":"10.1002/(SICI)1521-4044(19990401)50:4<156::AID-APOL156>3.0.CO;2-5","url":null,"abstract":"<p>A simple, reproducible, already introduced grafting method of methacrylic monomers onto carbon fibers is applied to cyano-biphenyl containing liquid crystalline (lc) monomers. The development of lc phases is faster and more uniform in the presence of carbon fibers. Applying a voltage to the grafted carbon fibers, causes phase transitions of the liquid crystals. By varying spacer length of the grafted lc polymers the physico-chemical properties, e. g. wetting and electrokinetic behavior (zeta-potential) are significantly influenced.</p>","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"50 4","pages":"156-162"},"PeriodicalIF":0.0,"publicationDate":"1999-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89565060","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}

{"title":"Degree of branching in hyperbranched polymers. 3 Copolymerization of ABm-monomers with AB and ABn-monomers","authors":"H. Frey,&nbsp;D. Hölter","doi":"10.1002/(SICI)1521-4044(19990201)50:2/3<67::AID-APOL67>3.0.CO;2-W","DOIUrl":"10.1002/(SICI)1521-4044(19990201)50:2/3<67::AID-APOL67>3.0.CO;2-W","url":null,"abstract":"<p>Extending the considerations of previous work (<i>Acta Polym.</i><b> 1997</b>,<i> 48</i>, 30;<i> Acta Polym.</i><b> 1997</b>,<i> 48</i>, 298) the degree of branching (DB) and the average number of branches per non-terminal monomer unit (ANB) are defined and calculated for random copolycondensation of AB_<i>m</i> with AB monomers as well as AB_<i>m</i> with AB_<i>n</i>-monomers in general. Copolymerization of linear AB-comonomers can be used to deliberately lower the DB and ANB of hyperbranched polymers. The DB<math>\u0000 <msub>\u0000 <mtext> </mtext>\u0000 <mrow>\u0000 <mtext>AB/AB</mtext>\u0000 <msub>\u0000 <mtext> </mtext>\u0000 <mrow>\u0000 <mtext>2</mtext>\u0000 </mrow>\u0000 </msub>\u0000 </mrow>\u0000 </msub></math> for copolycondensation of AB and AB₂ monomers in dependence on the monomer ratio <i> r</i> = [AB]/[AB₂] and conversion <i> p</i>_<i>A</i> is DB<math>\u0000 <msub>\u0000 <mtext> </mtext>\u0000 <mrow>\u0000 <mtext>AB/AB</mtext>\u0000 <msub>\u0000 <mtext> </mtext>\u0000 <mrow>\u0000 <mtext>2</mtext>\u0000 </mrow>\u0000 </msub>\u0000 </mrow>\u0000 </msub></math> = 2 <i>p</i>_<i>A</i> <i> r</i> + 1/(<i> r</i> + 2)². The DB<math>\u0000 <msub>\u0000 <mtext> </mtext>\u0000 <mrow>\u0000 <mtext>AB/AB</mtext>\u0000 <msub>\u0000 <mtext> </mtext>\u0000 <mrow>\u0000 <mtext>2</mtext>\u0000 </mrow>\u0000 </msub>\u0000 </mrow>\u0000 </msub></math> for copolymerization is compared to the DB for AB₂ homopolymerization,showing that a relatively small fraction of AB₂ comonomers suffices to obtain considerable degrees of branching. Also, the DB<math>\u0000 <msub>\u0000 <mtext> </mtext>\u0000 <mrow>\u0000 <mtext>AB/AB</mtext>\u0000 <msub>\u0000 <mtext> </mtext>\u0000 <mrow>\u0000 <mtext>3</mtext>\u0000 </mrow>\u0000 </msub>\u0000 </mrow>\u0000 </msub></math> and ANB<math>\u0000 <msub>\u0000 <mtext> </mtext>\u0000 <mrow>\u0000 <mtext>AB/AB</mtext>\u0000 <msub>\u0000 <mtext> </mtext>\u0000 <mrow>\u0000 <mtext>3</mtext>\u0000 </mrow>\u0000 </msub>\u0000 </mrow>\u0000 </msub></math> for copolycondensation of AB and AB₃-monomers are calculated. Finally, a general expression for the DB<math>\u0000 <msub>\u0000 <mtext> </mtext>\u0000 <mrow>","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"50 2-3","pages":"67-76"},"PeriodicalIF":0.0,"publicationDate":"1999-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75479858","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}

{"title":"Highly regioregular poly(3-alkylthiophenes): a new synthetic route and characterization of the resulting polymers","authors":"A. Bolognesi,&nbsp;W. Porzio,&nbsp;G. Bajo,&nbsp;G. Zannoni,&nbsp;L. Fannig","doi":"10.1002/(SICI)1521-4044(19990401)50:4<151::AID-APOL151>3.0.CO;2-P","DOIUrl":"10.1002/(SICI)1521-4044(19990401)50:4<151::AID-APOL151>3.0.CO;2-P","url":null,"abstract":"<p>We have recently synthesized a series of poly(3-alkylthiophenes) with a new simple procedure which has allowed to prepare 96–100% regioregular polymers. This work describes this synthetic pathway and reports the characterization of a poly(3-alkylthiophene) series obtained through this method.</p>","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"50 4","pages":"151-155"},"PeriodicalIF":0.0,"publicationDate":"1999-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88838154","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}

{"title":"Synthesis and characterization of new adamantane-type cardo polyamides","authors":"Der-Jang Liaw,&nbsp;Been-Yang Liaw,&nbsp;Chao-Yi Chung","doi":"10.1002/(SICI)1521-4044(19990401)50:4<135::AID-APOL135>3.0.CO;2-H","DOIUrl":"10.1002/(SICI)1521-4044(19990401)50:4<135::AID-APOL135>3.0.CO;2-H","url":null,"abstract":"<p>In this work, a new adamantane-type cardo dicarboxylic acid containing ether group, 2,2-bis[4-(carboxyphenoxy)phenyl]-adamantane (<b>BCAPA</b>), was prepared from 2,2-bis(4-hydroxyphenyl)adamantane and <i>p</i>-fluorobenzonitrile via the aromatic nucleophilic substitution reaction followed by hydrolysis. A series of new polyamides were prepared by the direct polycondensation of <b>BCAPA</b> and various diamines utilizing Yamazaki reaction conditions. The polymers were produced with moderate to high inherent viscosities of 0.65–1.06 dl g^–1. The polymers, except polymers <b>PA4</b>, <b>PA7</b> and <b>PA8</b>, exhibited weight-average molecular weight and number-average molecular weight in the range of 57 400–106 000 and 32 500–58 200, respectively. Nearly all the polymers were readily soluble in polar solvents such as <i>N</i>-methyl-2-pyrrolidinone, <i>N,N</i>-dimethylacetamide, and <i>N,N</i>-dimethylformamide, as well as less polar solvents such as dimethyl sulfoxide, pyridine and <i>γ</i>-butyrolactone, and also in tetrahydrofuran. All of the polymers were amorphous and the polyamide films had a tensile strength and tensile modulus above 86 MPa and 2.0 GPa. These polyamides had glass transition temperatures between 254–292°C and 10% weight loss temperatures in the range of 450–507 and 481–516°C in nitrogen and air atmosphere, respectively.</p>","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"50 4","pages":"135-140"},"PeriodicalIF":0.0,"publicationDate":"1999-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88756158","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}

{"title":"Two different, on the same silica supported metallocene catalysts, activated by various trialkylaluminums – a kinetic and morphological study as well as an experimental investigation for building stereoblock polymers","authors":"C. Przybyla,&nbsp;G. Fink","doi":"10.1002/(SICI)1521-4044(19990201)50:2/3<77::AID-APOL77>3.0.CO;2-U","DOIUrl":"10.1002/(SICI)1521-4044(19990201)50:2/3<77::AID-APOL77>3.0.CO;2-U","url":null,"abstract":"<p>The main focus of this study is the development of new polypropylene macromolecules. The simultaneous supporting of two metallocenes that manufacture polyolefins of different tacticity on the same silica should yield stereoblock polymers of polypropylene, if a chain transfer between the active species takes place. As chain transfer agents two aluminumalkyls (cocatalyst and scavenger) of distinct steric demands were chosen. Two catalyst systems were studied. The first was based on a PQ-silica/MAO on which the two metallocene catalysts rac-Me₂Si[Ind]₂ZrCl₂ (isotactic working species) and<i> i</i>-Pr[FluCp]-ZrCl₂ (syndiotactic working species) were fixed. For the second the components rac-Me₂Si[IndR₂]₂ZrCl₂ and<i> i</i>-Pr[FluCp]-ZrCl₂ were fixed to a Grace Silica/MAO-support. The influence of the type of silica, of MAO-content, of the kind of scavenger and of the supporting procedure on the microstructure, the kinetics and the morphology of the product were investigated.</p>","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"50 2-3","pages":"77-83"},"PeriodicalIF":0.0,"publicationDate":"1999-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85256893","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}

{"title":"Tailored rigid-flexible block copolymers. 5. Synthesis and amphiphilic behavior of diblocks of poly(p-benzamide) and poly(ethylene glycol)","authors":"A. Gabellini,&nbsp;M. Novi,&nbsp;A. Ciferri,&nbsp;C. Dell'Erba","doi":"10.1002/(SICI)1521-4044(19990401)50:4<127::AID-APOL127>3.0.CO;2-D","DOIUrl":"10.1002/(SICI)1521-4044(19990401)50:4<127::AID-APOL127>3.0.CO;2-D","url":null,"abstract":"<p>Tailored diblock copolymers of rigid poly(<i>p</i>-benzamide) (PBA) and flexible poly(ethylene glycol) (PEG) were prepared using two different polymerization schemes: (i) the one-pot two-step scheme of the Yamazaki reaction including benzoyl-terminated PBA and a PEG methyl ether modified by<i> p</i>-aminobenzoylation; (ii) the polymerization of<i> p</i>-aminobenzoic acid in the presence of the above NH₂-terminated PEG. The former method yields a copolymer coexisting with a large amount of PBA homopolymer. The latter method yields a copolymer with a reduced and controlled amount of unblocked PBA. The fraction of flexible segments in the copolymers varied between ca. 0.60 and ca. 0.40. In solutions of<i> N,N</i>-dimethylacetamide/LiCl, the solubility of the flexible homopolymer is larger at low LiCl content when the solubility of rigid PBA is, instead, negligeably small. However, large quantities of the latter are solubilized at low LiCl content, provided the copolymer is also present. The order of increasing solubility of the two components is reversed at high LiCl content. Micellar-type organizations of the amphiphilic copolymer with the rigid homopolymer are postulated. A lyotropic mesophase appears at a copolymer volume fraction <i>v</i>_pⁱ ca. 0.06 and it is fully formed at <i>v</i>_p^a ca. 0.08. The evolution of the structurization from diluted solutions to the mesophase and to the solid state is briefly considered.</p>","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"50 4","pages":"127-134"},"PeriodicalIF":0.0,"publicationDate":"1999-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85493073","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}

{"title":"Relaxation in the glass transition regime interpreted in terms of the aggregate model","authors":"M. Köpf,&nbsp;H.G. Kilian","doi":"10.1002/(SICI)1521-4044(19990401)50:4<109::AID-APOL109>3.0.CO;2-D","DOIUrl":"10.1002/(SICI)1521-4044(19990401)50:4<109::AID-APOL109>3.0.CO;2-D","url":null,"abstract":"<p>The retardation time spectra in the glass transition range are discussed on hand of multidimensional deuteron NMR experiments, measurements of the dielectric loss and the <i> T</i>₁-relaxation of proton spins in liquids at different temperatures and different frequencies. The data can be described by applying the model of reversible aggregation. Every liquid is here characterized by a broad aggregate size distribution. Relaxation is interpreted as collective response of intra-aggregate Debye processes running off while the aggregate ensemble fluctuates. The relaxation time increases with the volume of the aggregate so that every relaxation time distribution is strictly related to the aggregate size distribution. The shape of relaxation mode distributions is similar, the width depends on how the molecular mechanisms couple to the stationary dynamics. The coupling changes on heating so that the width of the relaxation mode distribution decreases. A full description of the α-process needs to account for aggregate ensemble fluctuations, a bimodal relaxation mode spectrum and a heterogeneous kinetics.</p>","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"50 4","pages":"109-121"},"PeriodicalIF":0.0,"publicationDate":"1999-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75047089","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}

{"title":"Synthesis of OH-functionalized poly(p-xylylene)s by reductive coupling polymerization of aromatic dialdehydes with catalytic amounts of divalent samarium compounds","authors":"N.E. Brandukova-Szmikowski,&nbsp;A. Greiner","doi":"10.1002/(SICI)1521-4044(19990401)50:4<141::AID-APOL141>3.0.CO;2-T","DOIUrl":"https://doi.org/10.1002/(SICI)1521-4044(19990401)50:4<141::AID-APOL141>3.0.CO;2-T","url":null,"abstract":"<p>The focus of this study is on reductive couplings of aromatic monoaldehydes and dialdehydes utilizing catalytic amounts of Sm(<span>II</span>) compounds and different co-reductants such as Mg turnings and Mg/Hg alloy in the presence of trimethylsilylchloride (TMSiCl). High educt and no side products have been observed using 10 mol% of SmI₂ and excess of Mg turnings activated by C₂H₄Br₂ in the presence of TMSiCl. Low yields of hydrobenzoin were observed when SmCp₂ replaced SmI₂. The reductive coupling polymerization of aromatic dialdehydes can be conducted under catalytic conditions with 12 mol% of SmI₂ and excess of Mg or Mg/Hg in the presence of TMSiCl in THF. OH-functionalized PPXs were obtained with moderate yields polymer and <i>M</i>_n of up to 16 000 g/mol.</p>","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"50 4","pages":"141-144"},"PeriodicalIF":0.0,"publicationDate":"1999-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"137869398","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}

{"title":"Synthesis of a self-doped polyaniline by nucleophilic addition","authors":"H. Salavagione,&nbsp;G.M. Morales,&nbsp;M.C. Miras,&nbsp;C. Barbero","doi":"10.1002/(SICI)1521-4044(19990101)50:1<40::AID-APOL40>3.0.CO;2-8","DOIUrl":"10.1002/(SICI)1521-4044(19990101)50:1<40::AID-APOL40>3.0.CO;2-8","url":null,"abstract":"","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"50 1","pages":"40-44"},"PeriodicalIF":0.0,"publicationDate":"1999-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91112570","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}

{"title":"Synthesis of OH-functionalized poly(p-xylylene)s by reductive coupling polymerization of aromatic dialdehydes with stoichiometric amounts of divalent samarium compounds","authors":"N. E. Brandukova-Szmikowski,&nbsp;S. Agarwal,&nbsp;A. Greiner","doi":"10.1002/(SICI)1521-4044(19990101)50:1<35::AID-APOL35>3.0.CO;2-H","DOIUrl":"10.1002/(SICI)1521-4044(19990101)50:1<35::AID-APOL35>3.0.CO;2-H","url":null,"abstract":"<p>Reductive coupling of aromatic carbonyl compounds in the presence of stoichiometric amounts of Sm(II) compounds such as SmI₂, SmI₂/TMSiCl, SmBr₂, Sm/TMSiBr, SmCp₂ resulted in hydrobenzoin derivatives. OH-functionalized poly(<i>p</i>-xylylene)s (OH-PPX) were obtained by reductive coupling of aromatic dialdehydes. The usage of solubilizing groups as well as the use of trimethylsilylchloride (TMSiCl) and trimethylsilylbromide (TMSiBr) enhanced the polymerizability of monomers under study. In spite of moderate yields high molecular weight polymers were obtained.</p>","PeriodicalId":7162,"journal":{"name":"Acta Polymerica","volume":"50 1","pages":"35-39"},"PeriodicalIF":0.0,"publicationDate":"1999-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77998575","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}