共查询到20条相似文献,搜索用时 15 毫秒
1.
Matthew Laskoski Dawn D. Dominguez Teddy M. Keller 《Journal of polymer science. Part A, Polymer chemistry》2005,43(18):4136-4143
A multiple aromatic ether linked phthalonitrile was synthesized and characterized. The oligomeric phthalonitrile monomer was prepared from the reaction of an excess amount of bisphenol A with 4,4′‐difluorobenzophenone in the presence of K2CO3 as the base in an N,N‐dimethylformamide/toluene solvent mixture, followed by end capping with 4‐nitrophthalonitrile in a two‐step, one‐pot reaction. The monomer properties were compared to those of the known resin 2,2‐bis[4‐(3,4‐dicyanophenoxy)phenyl]propane after being cured in the presence of bis[4‐(4‐aminophenoxy)phenyl]sulfone. Rheometric measurements and thermogravimetric analysis showed that the oligomeric phthalonitrile resin maintained good structural integrity upon heating to elevated temperatures and exhibited excellent thermal properties along with long‐term oxidative stability. The ether‐linked phthalonitrile resin absorbed less than 2.5% water by weight after exposure to an aqueous environment for extended periods. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4136–4143, 2005 相似文献
2.
Synthesis of bisphenol A‐free oligomeric phthalonitrile resins with sulfone and sulfone‐ketone containing backbones
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Matthew Laskoski Jadah S. Clarke Arianna Neal Holly L. Ricks‐Laskoski W. Judson Hervey Teddy M. Keller 《Journal of polymer science. Part A, Polymer chemistry》2016,54(11):1639-1646
Two new oligomeric sulfone and sulfone‐ketone containing phthalonitrile (PN) resins with excellent processability have been developed. The PN monomers were prepared from the reaction of an excess amount of bisphenol S with 4‐(chlorophenyl)sulfone or 4,4‐dichlorobenzophenone in the presence of a base in a solvent mixture (dimethylsulfoxide/toluene), followed by end‐capping with 4‐nitro‐PN in a two‐step, one‐pot reaction. These PN resins exhibited good viscosities and cure times for molding into various shapes. After being thermally cured to yield crosslinked polymers, these polymers demonstrated superb mechanical properties, thermo‐oxidative stability, and maintained good dielectric properties. Published 2016. 1 J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1639–1646 相似文献
3.
Matthew Laskoski Arianna Neal Mollie B. Schear Teddy M. Keller Holly L. Ricks‐Laskoski Andrew P. Saab 《Journal of polymer science. Part A, Polymer chemistry》2015,53(18):2186-2191
A versatile synthetic method has been developed for oligomeric aliphatic–aromatic ether containing phthalonitrile (PN) resins and applied to the preparation of three unique resin systems. The oligomeric PN monomers were prepared from the reaction of an excess amount of bisphenol A with a dihalo‐aliphatic containing compound in the presence of K2CO3 in dimethylsulfoxide, followed by end‐capping with 4‐nitrophthalonitrile in a two‐step, one‐pot reaction. These PN resin systems exhibited excellent viscosities for molding various shaped articles after thermal curing to yield crosslinked polymers. These polymers offered more mechanical flexibility, when compared with an all aromatic backbone, while still maintaining good thermal stability, dielectric properties, and low water absorption. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 2186–2191 相似文献
4.
Eda Gungor Cigdem Bilir Hakan Durmaz Gurkan Hizal Umit Tunca 《Journal of polymer science. Part A, Polymer chemistry》2009,47(22):5947-5953
Azidopropyl‐heptaisobutyl‐substituted polyhedral oligomeric silsesquioxane (POSS‐N3) was reacted with 1,1,1‐tris[4‐(2‐propynyloxy)phenyl]‐ethane ( 1 ) and poly(ethylene glycol) (PEG)‐b‐poly(methyl methacrylate) (PMMA) copolymer with alkyne at its center (PEG‐PMMA‐alkyne) affording the first time synthesis of 3‐arm star POSS and PEG‐PMMA‐POSS 3‐miktoarm star terpolymer, respectively, in the presence of CuBr/N,N,N′,N″,N″‐pentamethyldiethylenetriamine as catalyst and N,N‐dimethylformamide/tetrahydrofuran as solvent at room temperature. The precursors and the target star polymers were characterized comprehensively by 1H NMR, GPC, and DSC. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 5947–5953, 2009 相似文献
5.
Eda Gungor Cigdem Bilir Gurkan Hizal Umit Tunca 《Journal of polymer science. Part A, Polymer chemistry》2010,48(21):4835-4841
Azide end‐functionalized polyhedral oligomeric silsesquioxane (POSS‐N3) was incorporated into the periphery of well‐defined alkyne‐polystyrene50‐poly(divinyl benzene) (alkyne‐PS50‐polyDVB) and alkyne‐poly(tert‐butyl acrylate)43‐poly(divinyl benzene) (alkyne‐PtBA43‐polyDVB) multiarm star polymers via highly efficient azide‐alkyne click reaction, resulting in POSS‐PS50‐polyDVB and POSS‐PtBA43‐polyDVB multiarm star block copolymers respectively, in the solution of tetrahydrofuran/N,N‐dimethyl formamide, CuBr/N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA) at room temperature for 24 h. Linear precursors and star polymers obtained in this study were characterized 1H NMR, gel permeation chromatography (GPC), and triple detection GPC (TD‐GPC). Absolute molecular weight, hydrodynamic radius, and intrinsic viscosity ([η]) values for all star polymers were determined by TD‐GPC. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
6.
Parvin Zare Maria Mahrova Emilia Tojo Anja Stojanovic Wolfgang H. Binder 《Journal of polymer science. Part A, Polymer chemistry》2013,51(1):190-202
A facile synthetic route for the preparation of dicationic ethylene glycol based‐ionic liquids (ILs) via the azide/alkyne “click” reaction is presented. The copper(I) catalyzed, microwave‐assisted azide/alkyne “click” reaction between diazido‐ethylene glycols and the corresponding alkyne containing IL‐head group enables a simple preparation of different sets of poly(ethylene glycol)‐based ILs. Beside tetra‐ and hexa(ethylene glycol)‐based ILs, also oligomeric (Mn = 400 g/mol) and polymeric ILs (Mn up to 1550 g/mol) could be prepared in good yield and with full conversion of the ionic head group. The prepared ILs were extensively characterized via NMR spectroscopy and ESI‐time‐of‐flight (TOF) mass spectroscopy, revealing the formation of multiply charged ions in the negative mode. Thermal stability proved to be exceptionally high (up to 300 °C) together with low glass‐transition temperatures. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
7.
Phthalonitrile endcapped oligomers containing aromatic ether and imide linkages have been synthesized and characterized. The phthalonitrile terminated oligomers were prepared in two step (one spot) method by the reaction of an excess amount of pyromellitc dianhydride (PMDA) with aromatic diamines, in a N,N-dimethylacetamide (DMAc)/toluene solvent mixture to form anhydride terminated oligomeric intermediate that was terminated by the reaction with 4-(aminophenoxy) phthaloitrile. The average molecular weights of the prepared oligomers were determined by GPC analysis. The oligomeric phthalonitrile monomers have been converted to network polymers using 4,4'-diaminodiphenyl sulfone (DDS) (5.0 wt %) curing additive at elevated temperatures. Differential scanning calorimetric (DSC) analysis was used to follow the polymerization as the oligomeric phthalonitrile/diamine mixtures and prepolymers. An isothermal rheometric analysis was conducted to determine the complex viscosity of the prepolymers during polymerization reaction. Viscosity increases as a function of time due to crosslinking, which depends upon the concentration and reactivity of the curing agent. The TGA analysis of cured resins showed superior thermal and thermo-oxidative stability. The temperature of 10% weight loss from TGA are in the range of 498-511 °C in N2 and 448–461 °C in air atmosphere. Char yield at 800 °C is 41.7–50.2% in air and 70.6–83.1% in N2. 相似文献
8.
Chen Gao Ying Wang Pengfei Gou Xia Cai Xiaodong Li Weipu Zhu Zhiquan Shen 《Journal of polymer science. Part A, Polymer chemistry》2013,51(13):2824-2833
Well‐defined amphiphilic A8B4 miktoarm star copolymers with eight poly(ethylene glycol) chains and four poly(ε‐caprolactone) arms (R‐8PEG‐4PCL) were prepared using “click” reaction strategy and controlled ring‐opening polymerization (CROP). First, multi‐functional precursor (R‐8N3‐4OH) with eight azides and four hydroxyls was synthesized based on the derivatization of resorcinarene. Then eight‐PEG‐arm star polymer (R‐8PEG‐4OH) was prepared through “click” reaction of R‐8N3‐4OH with pre‐synthesized alkyne‐terminated monomethyl PEG (mPEG‐A) in the presence of CuBr/N,N,N′,N″,N″′‐ pentamethyldiethylenetriamine (PMDETA) in DMF. Finally, R‐8PEG‐4OH was used as tetrafunctional macroinitiator to prepare resorcinarene‐centered A8B4 miktoarm star copolymers via CROP of ε‐caprolactone utilizing Sn(Oct)2 as catalyst at 100 °C. These miktoarm star copolymers could self‐assemble into spherical micelles in aqueous solution with resorcinarene moieties on the hydrophobic/hydrophilic interface, and the particle sizes could be controlled by the ratio of PCL to PEG. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2824–2833. 相似文献
9.
Matthew Laskoski Dawn D. Dominguez Teddy M. Keller 《Journal of polymer science. Part A, Polymer chemistry》2006,44(15):4559-4565
New multiple aromatic ether containing oligomeric cyanate ester resins have been synthesized using a modified Ullmann reaction. The oligomeric monomers were prepared by reacting resorcinol and 1,3‐ or 1,4‐dibromobenzene in the presence of potassium carbonate and a catalytic amount of a copper(I) complex in a N,N‐dimethylformamide/toluene mixture. The hydroxyl terminated intermediates were end‐capped with the cyanate moiety by reaction with cyanogen bromide in the presence of triethylamine in dry acetone. The oligomeric cyanate ester monomers are liquid at room temperature, which enhance their processability to polymeric networks. The thermo‐oxidative properties were determined for the new cyanate ester polymers as well as their storage modulus. The length of the aromatic ether spacer between the terminal cyanate ester groups was varied to investigate the effect of changing the spacer length on the properties of the material. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4559–4565, 2006 相似文献
10.
Masakatsu Kasuya Tatsuo Taniguchi Ryuhei Motokawa Michinari Kohri Keiki Kishikawa Takayuki Nakahira 《Journal of polymer science. Part A, Polymer chemistry》2013,51(19):4042-4051
We developed a novel fluorescence labeling technique for quantification of surface densities of atom transfer radical polymerization (ATRP) initiators on polymer particles. The cationic P(St‐CPEM‐C4DMAEMA) and anionic P(St‐CPEM) polymer latex particles carrying ATRP‐initiating chlorine groups were prepared by emulsifier‐free emulsion polymerization of styrene (St), 2‐(2‐chloropropionyloxy)ethyl methacrylate (CPEM), and N‐n‐butyl‐N,N‐dimethyl‐N‐(2‐methacryloyloxy)ethylammonium bromide (C4DMAEMA). ATRP initiators on the surface of polymer particles were converted into azide groups by sodium azide, followed by fluorescent labeling with 5‐(N,N‐dimethylamino)‐N′‐(prop‐2‐yn‐1‐yl)naphthalene‐1‐sulfonamide (Dansyl‐alkyne) by copper‐catalyzed azide‐alkyne cycloaddition (CuAAC). The reaction time required for both azidation of ATRP‐initiating groups and successive fluorescence labeling of azide groups with Dansyl‐alkyne by CuAAC were investigated in detail by FTIR and fluorescence spectral measurement, respectively. The ATRP initiator densities on the cationic P(St‐CPEM‐C4DMAEMA) and anionic P(St‐CPEM) particle surfaces were estimated to be 0.21 and 0.15 molecules nm?2, respectively, which gave close agreement with values previously determined by a conductometric titration method. The fluorescence labeling through click chemistry proposed herein is a versatile technique to quantify the surface ATRP initiator density both on anionic and cationic polymer particles. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4042–4051 相似文献
11.
Hakan Durmaz Aydan Dag Elif Erdogan A. Levent Demirel Gurkan Hizal Umit Tunca 《Journal of polymer science. Part A, Polymer chemistry》2010,48(1):99-108
The synthesis of multiarm star block (and mixed‐block) copolymers are efficiently prepared by using Cu(I) catalyzed azide‐alkyne click reaction and the arm‐first approach. α‐Silyl protected alkyne polystyrene (α‐silyl‐alkyne‐PS) was prepared by ATRP of styrene (St) and used as macroinitiator in a crosslinking reaction with divinyl benzene to successfully give multiarm star homopolymer with alkyne periphery. Linear azide end‐functionalized poly(ethylene glycol) (PEG‐N3) and poly (tert‐butyl acrylate) (PtBA‐N3) were simply clicked with the multiarm star polymer described earlier to form star block or mixed‐block copolymers in N,N‐dimethyl formamide at room temperature for 24 h. Obtained multiarm star block and mixed‐block copolymers were identified by using 1H NMR, GPC, triple detection‐GPC, atomic force microscopy, and dynamic light scattering measurements. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 99–108, 2010 相似文献
12.
Cheng Liu Jinyan Wang Encheng LinLishuai Zong Xigao Jian 《Polymer Degradation and Stability》2012,97(3):460-468
Three novel series of soluble and curable phthalonitrile-terminated oligomeric poly(ether imide)s containing phthalazinone moiety were synthesized from an excess amount of three dianhydrides and phthalazinone-based diamine, followed by reacting with 4-(3-aminophenoxy)phthalonitrile (APPh) in a two-step, one-pot reaction, respectively. The phthalonitrile oligomers containing phthalazinone moiety were cured in the presence of 4,4′-diaminodiphenylsulfone (DDS). The oligomers and the crosslinked polymers were characterized by DSC, FT-IR and elemental analysis. These phthalonitrile oligomers containing phthalazinone groups were found to be soluble in some aprotic solvents, such as chloroform, pyridine, m-cresol and N-methyl-2-pyrrolidone (NMP). The crosslinked polymers were insoluble in all solvents. The thermal properties of the oligomers and the crosslinked polymers were evaluated using DSC and TGA analysis. The phthalonitrile oligomers showed high glass transition temperatures (Tgs) in the range of 214-256 °C and high decomposition temperatures with 10% weight loss (Td10%) ranging from 523 to 553 °C. The crosslinked polymers showed excellent thermal stability with the 10% weight loss temperatures ranging from 543 to 595 °C, but did not exhibit a glass transition temperature upon heating to 350 °C. 相似文献
13.
Ufuk Saim Gunay Hakan Durmaz Eda Gungor Aydan Dag Gurkan Hizal Umit Tunca 《Journal of polymer science. Part A, Polymer chemistry》2012,50(4):729-735
Well‐defined linear furan‐protected maleimide‐terminated poly(ethylene glycol) (PEG‐MI), tetramethylpiperidine‐1‐oxyl‐terminated poly(ε‐caprolactone) (PCL‐TEMPO), and azide‐terminated polystyrene (PS‐N3) or ‐poly(N‐butyl oxanorbornene imide) (PONB‐N3) were ligated to an orthogonally functionalized core ( 1 ) in a two‐step reaction mode through triple click reactions. In a first step, Diels–Alder click reaction of PEG‐MI with 1 was performed in toluene at 110 °C for 24 h to afford α‐alkyne‐α‐bromide‐terminated PEG (PEG‐alkyne/Br). As a second step, this precursor was subsequently ligated with the PCL‐TEMPO and PS‐N3 or PONB‐N3 in N,N‐dimethylformamide at room temperature for 12 h catalyzed by Cu(0)/Cu(I) through copper‐catalyzed azide‐alkyne cycloaddition and nitroxide radical coupling click reactions, yield resulting ABC miktoarm star polymers in a one‐pot mode. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
14.
Xiaohua He Chunyan Gao Wuqiong Sun Wei Huang Shaoliang Lin Deyue Yan 《Journal of polymer science. Part A, Polymer chemistry》2013,51(5):1040-1050
Well‐defined azobenzene‐containing side‐chain liquid crystalline diblock copolymers composed of poly[6‐(4‐methoxy‐azobenzene‐4′‐oxy) hexyl methacrylate] (PMMAZO) and poly(γ‐benzyl‐L ‐glutamate) (PBLG) were synthesized by click reaction from alkyne‐ and azide‐functionalized homopolymers. The alkyne‐terminated PMMAZO homopolymers were synthesized by copper‐mediated atom transfer radical polymerization with a bromine‐containing alkyne bifunctional initiator, and the azido‐terminated PBLG homopolymers were synthesized by ring‐opening polymerization of γ‐benzyl‐L ‐glutamate‐N‐carboxyanhydride in DMF at room temperature using an amine‐containing azide initiator. The thermotropic phase behavior of PMMAZO‐b‐PBLG diblock copolymers in bulk were investigated using differential scanning calorimetry and polarized light microscopy. The PMMAZO‐b‐PBLG diblock copolymers exhibited a smectic phase and a nematic phase when the weight fraction of PMMAZO block was more than 50%. Photoisomerization behavior of PMMAZO‐b‐PBLG diblock copolymers and the corresponding PMMAZO homopolymers in solid film and in solution were investigated using UV–vis. In solution, trans–cis isomerization of diblock copolymers was slower than that of the corresponding PMMAZO homopolymers. These results may provide guidelines for the design of effective photoresponsive anisotropic materials. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013 相似文献
15.
Ufuk Saim Gunay Bengu Ozsoy Hakan Durmaz Gurkan Hizal Umit Tunca 《Journal of polymer science. Part A, Polymer chemistry》2013,51(21):4667-4674
We report here a simple and universal synthetic pathway covering triple click reactions, Diels–Alder, copper‐catalyzed azide–alkyne cycloaddition (CuAAC), and nitroxide radical coupling (NRC), to prepare well‐defined graft copolymers with V‐shaped side chains. The Diels–Alder click reaction between the furan protected‐maleimide‐terminated poly(ethylene glycol) (PEG) and a trifunctional core ( 1 ) carrying an anthracene, alkyne, and bromide was carried out to yield the corresponding α‐alkyne‐ and α‐bromide‐terminated PEG (PEG‐alkyne/Br) in toluene at 110 °C. Subsequently, the polystyrene or polyoxanorbornene with pendant azide functionality as a main backbone is reacted with the PEG‐alkyne/Br and 2,2,6,6‐tetramethyl‐1‐piperidinyloxy (TEMPO)‐terminated poly(ε‐caprolactone) using the CuAAC and NRC reactions in a one‐pot fashion in N,N′‐dimethylformamide at room temperature to result in the target V‐shaped graft copolymers. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4667–4674 相似文献
16.
Yi Chen Yuanqin Xiong Chang Peng Wenyong Liu Yue Peng Weijian Xu 《Journal of Polymer Science.Polymer Physics》2013,51(20):1494-1504
Polyhedral oligomeric silsesquioxane hybrid temperature and pH double‐responsive hydrogels with organic–inorganic co‐crosslinked networks are synthesized by in situ, free‐radical polymerization of N‐isopropylacrylamide and dimethylaminoethyl methacrylate in the presence of both organic crosslinker N,N′‐methylenebis(acrylamide) (BIS) and inorganic crosslinker octavinyl polyhedral oligomeric silsesquioxane (OvPOSS) in tetrahydrofuran media. The resulting hydrogels (OR‐OvP gels) display obvious temperature and pH double responsiveness, OvPOSS particles dispersed in polymer make a dominant effect on the properties of gels. With the increase of OvPOSS, the aggregation of particles on nano‐ or microscale happens and causes a considerable change on the properties of gels, such as the lower critical solution temperature and better compression strength. Specially, the interconnected microporous structure of gels ascribed to the microphase separation results in faster deswelling rate, which makes the gel become attractive. Besides, the crosslink by BIS intensifies the heterogeneity of gels significantly, which could also be used to adjust the properties of gels. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2013 , 51, 1494–1504 相似文献
17.
Pengcheng Li Jie Dai Yi Xu Qichao Ran Yi Gu 《Journal of polymer science. Part A, Polymer chemistry》2019,57(14):1587-1592
A difunctional benzoxazine (coPh‐apa) with a conjugated alkyne group is synthesized by the oxidative coupling reaction from a monocycle‐benzoxazine (Ph‐apa) containing an alkyne group. A model compound, 1,4‐diphenylbutadiyne (coPa), is used to study the curing reaction process of coPh‐apa by DSC, Fourier transform infrared spectroscopy, and 13C NMR, and the results suggest that the conjugated alkyne groups are involved in the crosslinking reaction via the trimerization reaction of the conjugated alkynyl groups and the Diels–Alder reaction. Furthermore, thermal properties of the polybenzoxazine are studied by dynamic thermomechanical analysis and thermogravimetric analysis. A glass‐transition temperature (Tgs) of as high as 412 °C and a char yield of 75.6% at 800 °C under nitrogen are obtained with the aid of the conjugated alkyne groups. Its excellent heat resistance dominates most thermosetting resins and will serve for heat shields. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 1587–1592 相似文献
18.
Eda Gungor Hakan Durmaz Gurkan Hizal Umit Tunca 《Journal of polymer science. Part A, Polymer chemistry》2008,46(13):4459-4468
H‐shaped quintopolymer containing different five blocks: poly(ε‐caprolactone) (PCL), polystyrene (PS), poly(ethylene glycol) (PEG), and poly(methyl methacrylate) (PMMA) as side chains and poly(tert‐butyl acrylate) (PtBA) as a main chain was simply prepared from a click reaction between azide end‐functionalized PCL‐PS‐PtBA 3‐miktoarm star terpolymer and PEG–PMMA‐block copolymer with alkyne at the junction point, using Cu(I)/N,N,N′,N″,N″‐pentamethyldiethylenetriamine (PMDETA) as a catalyst in DMF at room temperature for 20 h. The H‐shaped quintopolymer was obtained with a number–average molecular weight (Mn) around 32,000 and low polydispersity index (Mw/Mn) 1.20 as determined by GPC analysis in THF using PS standards. The click reaction efficiency was calculated to have 60% from 1H NMR spectroscopy. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4459–4468, 2008 相似文献
19.
《Journal of Polymer Science.Polymer Physics》2018,56(5):362-374
The influence of crosslinking process on the resulting structural properties of phthalonitrile matrices is studied through theoretical and experimental investigations. Multiscale procedure for generating fully atomistic phthalonitrile networks with simulation of radical polymerization reactions and specific reactions of triazine formation at the mesoscale level is presented and applied to the case of phthalonitrile resin based on low‐melting monomer bis(3‐(3,4‐dicyanophenoxy)phenyl)phenyl phosphate. The structural properties of the generated networks of various conversions and with various amount of triazine are analyzed using the dissipative particle dynamics and atomistic molecular dynamics. Triazine‐containing networks are much sparser in comparison with triazine‐free ones in terms of simple cycle size. The values of density, coefficients of linear thermal expansion and glass transition temperatures (Tgs) agree with obtained experimental data, and are very similar for different crosslinking mechanisms. The dependence of Tg on conversion correlates well with the sol–gel transition in network structure. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018 , 56, 362–374 相似文献
20.
Matthias Schulz Susanne Tanner Haitham Barqawi Wolfgang H. Binder 《Journal of polymer science. Part A, Polymer chemistry》2010,48(3):671-680
The end‐to‐end cyclization of telechelic polyisobutylenes (PIB's) toward cyclic polyisobutylenes is reported, using either ring‐closing metathesis (RCM) or the azide/alkyne‐“click”‐reaction. The first approach uses bisallyl‐telchelic PIB's (Mn = 1650, 3680, 9770 g mol?1) and Grubbs 1st‐, 2nd‐, and 3rd‐generation catalyst leading to cyclic PIB's in 60–80% yield, with narrow polydispersities (Mw/Mn = 1.25). Azide/alkyne‐“click”‐reactions of bisalkyne‐telechelic PIB's (Mn = 3840 and 9820 g mol?1) with excess of 1,11‐diazido‐undecane leads to the formation of mixtures of linear/cyclic PIB's under formation of oligomeric cycles. Subsequent reaction of the residual azide‐moieties in the linear PIB's with excess of alkyne‐telechelic PEO enables the chromatographic removal of the resulting linear PEO‐PIB‐block copolymers by column chromatography. Thus pure cyclic PIB's can be obtained using this double‐“click”‐method, devoid of linear contaminants. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 671–680, 2010 相似文献