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1.
D. Wöhrle 《Polymer Bulletin》1980,3(4):227-232
Summary Covalently polymer bound Co(salen) 6a-c was synthesized starting from two macroporous resins 2a,b and a linear polystyrene 2c. Reaction of 2a-c with 5-chloromethylsalicylaldehyde to 3a-c, then with 1,2-diaminoethane to 4a-c and then with salicylaldehyde led to the metal free ligands 5a-c which could be metallized to 6a-c. 相似文献
2.
Summary Living polymerization of isobutylene (IB) and subsequent controlled synthesis of ABA block copolymers, such as poly(styrene-b-isobutylene-b-styrene) (PSt-PIB-PSt) and poly(p-methylstyrene-b-isobutylene-b-p-methylstyrene) (PpMeSt-PIB-PpMeSt), have been carried out by a simple and inexpensive conventional laboratory technique. The homo- and block copolymers obtained by using this technique have exhibited excellent molecular weight control and low polydispersity indexes. The living nature of IB polymerization has been demonstrated by the incremental monomer addition (IMA) method with the dicumyl methyl ether (DiCumOMe)/TiCl4 initiating system in the presence of 2,5-di-tert-butylpyridine (DtBP) proton trap. PSt-PIB-PSt and PpMeSt-PIB-PpMeSt block copolymers have been synthesized by sequential monomer addition: first living difunctional polyisobutylene (PIB) midsegment was prepared by difunctional initiator, then the second monomer was added to the charge. High blocking efficiencies and desired block copolymer structures have been obtained. 相似文献
3.
Masato Suzuki Ken Mizuno Tai-ichi Sakaya Katsuhide Otani Shiro Kobayashi Takeo Saegusa 《Polymer Bulletin》1989,22(5-6):435-440
Summary Deoxophostone family(2-phenyl-1,2-oxaphospholane1a, 2-phenyl-1,2-oxaphosphorlane1b, and 2-phenyl-1,2-thiaphospholane1c) copolymerized with acrylic acid without catalyst to produce the corresponding copolymers. The polymerization proceeded via a cyclic acyloxyphosphorane to produce poly-(phosphine oxide — ester)3a(or3b) from1a(or1b) and poly(phosphine oxide — thiolester)3c from1c, respectively, with acrylic acid. It is of interest that the copolymer from1c with acrylic acid was not poly(phosphine sulfide — ester)4 but3c. The reactions of1a or1b with pyruvic acid or 1,3-propane sultone were also investigated.The present authors dedicate this paper to the late Mr. Ken Mizuno. 相似文献
4.
Summary Di- and triblock copolymers of polyisobutylene PIB and poly(ethylene glycol) PEG have been prepared and characterized. The syntheses involved the capping with tolylene 2,4-diisocyanate TDI various molecular weight -phenyl--(p-phenol) polyisobutylenes C6H5-PIB-C6H4OH and ,-di-(p-phenol)polyisobutylenes HOC6H4-PIB-C6H4OH, or commercially available mono- and di-hydroxyl-terminated PEGs. In this manner a series of PIB-b-PEG diblock copolymers, and PEG-b-PIB-b-PEG and PIB-b-PEG-b-PIB triblock copolymers have been obtained. The complete removal of the prepolymers from these amphiphilic sequential copolymers by conventional solvent extraction techniques could not be achieved because of the very high emulsifying action of the latters. In contrast, satisfactory separation was obtained by column chromatography using mixed (polar/nonpolar) eluents. The blocking efficiencies and composition of the block copolymers have been determined.Part XL V of the Series on New Telechelic Polymers and Sequential Copolymers by Polyfunctional Initiator-Transfer Agents (Inifers). 相似文献
5.
Summary This paper reports new cationic ring-opening polymerization of a spirophosphorane, 5-phenyl-1, 4, 6, 9-tetraoxa-5-phosphaspiro (4, 4) nonane, 1. The polymerization of 1. was induced by cationic initiators such as methyl trifluoromethanesulfonate (MeOTf), BF3·OEt2, and Et3O+-BF4
– to give polymer 2 consisting of two different units, 2a and 2b. During the reaction cyclic phosphonate 3 and 1,4-dioxane were simultaneously produced. The formation of unit 2b is considered to be due mainly to the cationic ring-opening polymerization of 3. 相似文献
6.
Summary Various divinyl-Schiff's base ligands 3 were synthesized from 2-hydroxy-5-vinylbenzaldehyde (2) and diamines. Copolymerization of 3 with styrene directly leads to covalently polymer bound ligands 4. Introduction of Co(II) resulted in the formation of the chelates 6. Covalently polymer bound chelates show high activity for the reversible binding of dioxygen under formation of mononuclear superoxo complexes. The chelates exhibit good activities for the oxidation of 2,6-di-tert-butylphenol (9).Part 5: Ref. 1). 相似文献
7.
Summary Starting with Z-2, 3-diamino-2-butenedinitrile as diamine component the synthesis of the low molecular N,N,O,O-chelate 3.Co and its ligand 3 is optimized. An easy synthesis of the chelate 8.Co covalently bound on macroreticular resins is presented. The chelates 8.Co are the most active heterogenous catalysts for the valence isomerization of quadricyclane to norbornadiene today. 相似文献
8.
Summary The cationic polymerization of various α- and β-substituted vinyl ethers, initiated by 1-iodo-1-(2-methylpropyloxy)ethane
1 and tetrabuty lammonium perchlorate (TBAP) was investigated. The polymerization of 2,3-dihydrofuran (DHF, 3a) in CH2Cl2 at -40°C proceeds via opening of the ethylenic double bond and yields polymers with narrow molar mass distributions and high
glass transitions. The number average of molar mass increased linearly with conversion. Under these conditions, a controlled
polymerization of two propenyl ethers (1-ethoxypropene 2a and 2-methoxypropene 2b) and two other cyclic unsaturated ethers (3,4-dihydro-2H-pyran 3b and 5-methyl-2,3-dihydrofuran 3c) could not be achieved. Either transfer reactions or the decomposition of 1 prevented the formation of high molar mass polymers of these vinyl ethers. 相似文献
9.
Summary The solid state synthesis of a monosubstituted phthalocyanine 6 is described. 4-(4-Hydroxyphenoxy)-1,2-benzenedicarbonitrile is polymer bound to a chloromethylated macroreticular polystyrene, yielding polymer 3. Reaction of 3 with 4-phenoxy-1,2-benzenedicarbonitrile in the presence of zinc salt results in the formation of covalently bound polymeric phthalocyanine 5. 6 is obtained by cleavage with HBr/acetic acid.Part 1: Ref. 1 相似文献
10.
Novel poly(acenaphtylene-b-isobutylene-b-acenaphtylene) (PAc-PIB-PAc) triblock copolymers exhibiting thermoplastic elastomer (TPE) properties have been prepared. The synthesis involved the addition of acenaphtylene (Ac) to living polyisobutylene dications (PIB) obtained by living isobutylene (IB) polymerization induced by the dicumyl methyl ether (DiCumOMe)/TiCl4 initiating system at-80°C. The triblocks contain very short polyacenaphtylene (PAc) blocks (Mn9,000) and consequently yield very soft, low modulus TPEs. Efforts to develop conditions for the living carbocationic polymerization (LCPzn) of Ac have failed.For Part VIII of this subseries see J. P. Kennedy, S. Midha, B. Keszler: Macromolecules (in press) 相似文献
11.
Summary Linear and three-arm star tosyl-telechelic polyisobutylenes (i.e., PIB's carrying two and three p-toluene-sulfonic acid ester end groups, respectively) have been synthesized and characterized by a variety of techniques. Subsequently these prepolymers were used as macroinitiators for the ring opening polymerization of 2-methyl-2-oxazoline leading to linear poly(N-acetylethyleneimine-b-isobutylene-b-N-acetylethyleneimine) and three-arm star poly(N-acetylethyleneimine-b-isobutylene). High yields (78–98%) and blocking efficiencies (70–80%) have been obtained. The absence of free polyisobutylene in the product indicates highly efficient initiation of 2-methyl-2-oxazoline polymerization by the tosyl-telechelic polyisobutylene. The less than 100% blocking efficiencies are probably due to chain transfer to 2-methyl-2-oxazoline. Hydrolysis of these block copolymers yielded poly(ethyleneimine-b-isobutylenes).Present address: Department of Macromolecular Science, Case Western Reserve University, Cleveland, Ohio 44106.Present address: Central Research Institute for Chemistry, Hungarian Academy of Sciences, Budapest, Hungary. 相似文献
12.
Summary The synthesis and characterization of main chain liquid crystalline polyesters arising from 2,5-bispentyloxy substituted terephthalic aicd (3) and aromotic diols are described. 3 was prepared from diethyl 2,5-dihydroxyterephthalate and 1-bromopentane. The polyesters were prepared from 4,4-dihydroxybiphenyl (5), hydroquinone (6), 2,5-dimethyl hydroquinone (8) and the substituted terephthaloyl dichloride (4) in 1,1,2,2-terachloroethane. Their structures were characterized by 1H-NMR, GPC and elemental analyses; their thermal behavior was studied by DSC measurements, microscopy under polarized light, and thermogravimetric analyses. The melting points are in the range of 130–280°C. All of them except of those with a high amount of 2,5-dimethyl hydroquinone (8) form a nematic phase above their melting point. 相似文献
13.
Nabin Ch. Maity Sayed H.R. Abdi Rukhsana I. Kureshy Noor-ul H. Khan E. Suresh Ganga P. Dangi Hari C. Bajaj 《Journal of Catalysis》2011,277(1):123-127
Two new chiral Mn(III) macrocyclic salen complexes 1a and 1b were prepared for the enantioselective epoxidation of non-functionalized alkenes. A 5 mol% loading of these catalysts in the presence of pyridine N-oxide as an axial base and sodium hypochlorite or urea hydrogen peroxide adduct as oxidant worked well to give respective epoxides in high yields and ee (up to >95% in selected cases). The catalyst 1b with urea hydrogen peroxide adduct as an oxidant was recovered by precipitation with hexane and was reused up to four times with retention of enantioselectivity. 相似文献
14.
Summary Diblock copolymers of isobytylene (IB) — methyl vinyl ether (MeVE) have been prepared by sequential monomer addition by employing 2-chloro-2, 4, 4-trimethylpentane (TMPCl)/TiCl4 initiating system in the presence of nBu4NCl or dimethyl-acetamide (DMA) in CH2Cl2/hexanes at –80°C. In line with our earlier observations (1), living carbocationic polymerizations (LCPZn) were obtained in the presence of nBu4NCl (i.e., the molecular weight of the poly(vinyl methyl ether) segment increased upon TiCl4 addition), however, extensive chain transfer occurred in the presence of DMA. According to column chromatography analysis, the product prepared in the presence of nBu4NCl is essentially pure PIB-b-PMeVE diblock (96w%) contaminated with a very small amount (4w%) of PIB. In contrast, the product obtained with DMA contains only 21w% PIB-b-PMeVe together with 72w% PIB and 5w% PMeVe homopolymers. This large difference in blocking efficiencies suggests that the structures of the growing species are different in the presence of the common anion salt,nBu4NCl, and the electron donor, DMA.For paper LIII in this series see Polym. Bull., vol. 29/1 相似文献
15.
Lonnie L. Bryant Jr. James F. Kinstle Takeo Saegusa Shiro Kobayashi 《Polymer Bulletin》1986,15(3):227-231
Summary 5-Oxazolone (1a) and 4-methyl-5-oxazolone (1b) were found to serve as a nucleophilic monomer (MN) toward electrophilic monomers (ME) like acrylamide (AM) and 2-hydroxyethyl acrylate (HEA). Copolymerizations between these MN and ME monomers took place without added initiator at room temperature and at110 °C to give solid polymers having alternating structures of 3 and 4. The molecular weight of these alternating copolymers is not high. The copolymerization mechanism is explained in terms of zwitterionic intermediates involving a proton-transfer step. 相似文献
16.
Summary A new approach has been developed to transform the cationic polymerization of tetrahydrofuran (THF) into anionic block copolymerization of methyl methacrylate (MMA). Several telechelic polytetrahydrofurans with secondary amine end-groups (PTHF-NHR, where R = benzyl, n-butyl or phenyl) have been synthesized. The PTHF-NHR, where R is a phenyl group, can be almost completely metallated by sodium naphthalene to form the polymeric anion which will initiate quantitative polymerization of MMA to form a block copolymer, poly(MMA-b-THF-b-MMA), exhibiting thermoplastic elastomer properties of tensile strength 157kg/cm2 and elongation 700%. 相似文献
17.
The total synthesis of diblock copolymers comprising poly(p-chlorostyrene) (PpClSt) and polytetrahydrofuran (PTHF) segments have been accomplished. The syntheses involved the living polymerization of p-chlorostyrene (pClSt) by the 2-chloro-2,4,4-trimethylpentane/TiCl4 initiating system followed by the blocking of tetrahydrofuran (THF) from thesec-benzylic chlorine end-group of PpClSt in the presence of AgPF6 in THF at room temperature and quenching with methanol: A series of PpCISt-b-PTHF diblocks have been prepared. Themolecular weight of the PTHF segments increased with reactiontime. The blocking efficiency (Beff) calculated by1H NMRspectroscopy was nearly 100%.Paper XXXV in the series of Living carbocationic polymerization 相似文献
18.
Summary Macrocyclic diamides 2, 3 and 4 of 4,4,5,5-tetramethyl-3,6-dioxaoctanedioic acid were prepared. These compounds incorporated in poly (vinyl chloride) membranes show a remarkable selectivity for lithium ions. 相似文献
19.
Summary The extended conformation with non-staggeredtt conformation of the skeletal bonds, has been crystallized from the bulk by exposure of isotactic polystyrene (iPS) films to solvent vapor at room temperature. Due to the predominant intramolecular interaction between the adjacent phenyls, solvent molecules are required to provide the stability required for crystallization. A unit cell witha = 21 A,b = 16.4 A andc = 30.6 A, with 4 chains and 8–16 solvent molecules has been proposed. It is shown that the extended conformation exists with significant perpetuation in the amorphous zones of semicrystalline films containing the threefold helical structure. It is suggested that the lower melting temperature of the extended form is due to the requirement of the presence of the solvent molecule and not due to intramolecular instability. 相似文献
20.
Summary Poly[2,5-bis(dimethylsilyl)furan] (V), a copolymer with alternating furan and disilyl units, has been prepared by the Wurtz coupling of 2,5-bis(dimethylchlorosilyl)furan (II) with sodium metal dispersion in toluene. Lower molecular weight poly[2,5-bis(dimethylsilyl)furan] (IV) has been prepared by a similar condensation reaction with 2,5-bis(dimethylfluorosilyl)furan (III). IV and V have been characterized by 1H, 13C and 29Si NMR, IR, and UV spectroscopy as well as by GPC, TGA and elemental analysis. Photolysis of V in a benzene/methanol solution results in degradation of the polymer. 相似文献