摘要:

AbstractThin films were prepared on substrates, cleavage surface of KCl single crystal, and metallic copper, by reaction of 1,2,4,5‐tetracyanobenzene with the substrate at various temperatures. The films were characterized by elemental analysis, IR, and UV/VIS spectroscopies. The films were observed by scanning electron microscopy. The films produced on copper at temperatures between 300 and 400°C consisted of copper octacyanophthalocyanine and its polymer with ladder structure. The ratio of polymer to monomer increased with elevating the reaction temperature. The films were composed of ribbon‐like crystals. The film produced on copper above 450°C was composed of an amorphous and continuous layer of polymeric copper phthalocyanine. The film produced on KCl at temperatures between 250 and 350°C consisted of potassium octacyanophthalocyanine and its polymer with ladder structure. The film produced on KCl above 450°C was polymeric potassium phthalocyanine. Those films contained more metal content than that required stoichiom

ISSN:0887-624X    

DOI:10.1002/pola.1989.080271201

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractAromatic polyamides (aramids) having pendantt‐butyl group were synthesized by the direct polycondensation of 5‐t‐butylisophthalic acid with various aromatic diamines inN‐methyl‐2‐pyrrolidone (NMP) using triphenyl phosphite and pyridine as condensing agents. The aramids having inherent viscosities of 0.6–2.4 dL/g were obtained in quantitative yields. These polymers were readily soluble in various solvents such as NMP,N,N‐dimethylacetamide, dimethyl sulfoxide, and pyridine, and gave transparent, tough and flexible films by casting from the NMP solutions. The aramids had glass transition temperatures between 250 and 330°C, and started to lose weight around 350°C, with 10% weight loss being recorded at a

ISSN:0887-624X    

DOI:10.1002/pola.1989.080271202

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe derivation of a radical desorption coefficient in emulsion polymerization is presented, which takes into account the possible reactions of the desorbed radical in the aqueous phase as well as the competition between desorption and termination in polymer particles containing more than one radical. This model overcomes some important limitations of the previous models and is able to explain previously reported experimental results that the other models were unable to explain.

ISSN:0887-624X    

DOI:10.1002/pola.1989.080271203

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractWater‐soluble comb‐shaped polymers were prepared through grafting of poly(ethylene glycol) monomethyl ethers (MPEG) onto acrylic and methacrylic ester copolymers by transesterification reactions. The grafting was alkali‐catalyzed, and performed in refluxing toluene solution or in melt at 155°C. The grafting efficiency was found to be on the order of 1 graft/10 monomer units. Epoxy groups in glycidyl methacrylate copolymers were also utilized for grafting. The crude graft copolymers were purified through chromatography and characterized by NMR and IR spectroscopy. Polymers prepared from MPEG 2000 were crystalline with melting points 10–15°C lower than the MPEG used. All polymers were shown to be surface active with CMC on the order of 1.5 g/L, and surface tensions of 38–45 dyn/cm. When used as emulsifiers the graft copolymers containing bulky lipophilic ester groups (2‐ethylhexylt‐butyl) gave oil‐in‐water (o/w) and water‐in‐oil (w/o) emulsions from xylene/water with higher stability than those containing straight chain ester groups (methylnbutyln‐docecyl). The most stable emulsions were obtained by dissolving the poly

ISSN:0887-624X    

DOI:10.1002/pola.1989.080271204

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe major photoproduct from irradiation of triphenylsulfonium salts is a Brönsted acid. This photochemical process has been used in several polymer film applications where the acid is used for crosslinking of films or other acid catalyzed reactions. Despite the widespread application of these materials, very little is known about the efficiency of acid generation in polymer films or the extent of the catalytic chain. This paper describes the use of a merocyanine dye technique to analyze for acid production in polymer films. The amount of acid produced on irradiation can be determined by this method and the extent of the catalytic chain then be determined

ISSN:0887-624X    

DOI:10.1002/pola.1989.080271205

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractMetathesis ring opening polymerization has been used to copolymerize norbornene and 7,8‐bis(trifluoromethyl)tricyclo[4,2,2,02,5]deca‐3,7,9‐triene. Subsequent thermal elimination of the precursor copolymers yielded acetylene–norbornene copolymers. The undoped copolymers were found to have electrical conductivity, spin concentration, and EPR linewidths which vary with composition. The location of thetrans‐CH out‐of‐plane vibration, however, was invariant at 1010cm−1indicating that conjugation length ofn>4 are present even at 40% acetylene content in the copolymer. The copolymers containing 79 mol % of acetylene units attained a doped conductivity of 0.02 S/cm with a dopant concentration of 6 mol % of

ISSN:0887-624X    

DOI:10.1002/pola.1989.080271206

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractThis paper describes the synthesis and characterization of a series of (4‐alkoxyphenyl)phenyliodonium salts which are excellent photo‐ and thermal‐initiators for the cationic polymerization of vinyl and heterocyclic monomers. These compounds are easily prepared by straightforward synthetic techniques and display very good solubility and photoresponse characteristics which make them especially attractive for use in UV curing applications. Those compounds with alkoxy chains of eight carbons and longer are essentially non

ISSN:0887-624X    

DOI:10.1002/pola.1989.080271207

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe microstructure of the polymer formed by the hydrosilation of styrene with poly(hydrogenmethylsiloxane) was studied by1H‐ and13C‐NMR spectra. Two modes of addition in hydrosilation were found to occur randomly without the influence of the adjacent monomer unit by statistical analysis of sequence distribution of29Si‐NMR spe

ISSN:0887-624X    

DOI:10.1002/pola.1989.080271208

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractInitiation of polymerization of methyl methacrylate with redox system montmorillonite (with lattice Fe3+)–thiourea has been achieved. The rates are dependent on both clay mineral and thiourea. Amidosulfenyl radicals are believed to initiate the polymerization on the clay surface. The polymerization produced nonextractable clay–polymer adduct up to an extent of 70 wt %. The pH of the medium (in the acidic range) did not affect the polymerization r

ISSN:0887-624X    

DOI:10.1002/pola.1989.080271209

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe intrinsic and thermal characteristics of poly(styrenephosphonate diethyl ester)s (PSP) are described. The properties of the polymer prepared by two synthetic procedures, phosphorylation of monodispersed polystyrene and polymerization of vinylbenzenephosphonate ester, are compared with chloromethylated polystyrene and with each other. Empirical formulas are presented for the relationships between the degree of polymerization, degree of phosphorylation, molecular weight, and intrinsic viscosity (in methanol and toluene). Thermal analysis reveals a sharp drop inTgwith an increase in degree of phosphorylation;Tgof the fully phosphorylated polystyrene is in the range of 9–30°C. TheTgΔCpvalues show significant decrease with augmentation in the degree of phosphorylation, yielding a value of 14 cal g−1for the fully phosphorylated polymer, compared with ∼ 29 cal g−1for the parent polymer. The PSP is shown to have substantial capacity for dissolving heavy metal salts, such as UO2(NO3)2, causing significant elevation

ISSN:0887-624X    

DOI:10.1002/pola.1989.080271210

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY