摘要:

AbstractWater‐soluble graft copolymers of well‐defined structure having hydrophobic polymethacrylate branches with different ester groups were prepared by the macromonomer method. Methacrylate macromonomers of controlled molecular weights having a methacryloyloxyl end group were synthesized by radical polymerization of the corresponding monomer in the presence of thioglycolic acid followed by the reaction of glycidyl methacrylate with the terminal carboxyl group. These macromonomers were copolymerized with methacrylic acid and methyl methacrylate to prepare tailor‐made graft copolymers composed of a hydrophlic backbone and different kinds of hydrophobic branches, which were characterized by elemental analysis, NMR, and GPC. The viscosities of the aqueous solutions of the sodium salts of these graft copolymers were measured. It was found that the viscosity of the dilute solution of the graft copolymer was remarkably high compared with the corresponding random copolymer irrespective of the ester group in branch segments. Solubilizing behavior of Orange‐OT in aqueous solutions of the graft copolymers and the random copolymer were also investigated to study the nature of the hydrophobic domain of the graft cop

ISSN:0887-624X    

DOI:10.1002/pola.1989.080270401

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractNovel poly(amide‐sulfonamide)s have been prepared by reacting terephthaloyl, isophthaloyl, and sebacoyl chloride with variously substituted dianilines containing preformed sulfonamide linkages. Inherent viscosities of the prepared polymers ranged from 0.19 to 0.58 dL/g. Despite low apparent viscosities, the polymers had film forming properties. Clear, tough, flexible films were obtained from the prepared polymers, in particular the poly(terephthalamide‐sulfonamide)s. Glass transition temperatures, determined by differential scanning calorimetry, ranged from 84 to 247°C. Thermogravimetric analyses of the polymers showed that they have moderate thermal stability with weight losses ranging from 12 to 35% at 3

ISSN:0887-624X    

DOI:10.1002/pola.1989.080270402

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractSecond‐order kinetics were found applicable to the isothermal enthalpy release after quenching from a high temperature. The kinetic behavior was unaffected by different amounts of initial excess enthalpy. The activation enthalpy obtained from the temperature dependence of the second order rate constant was 200 kcal/mol or 837 kJ/mol which could be compared with 736 kJ/mol for volume recovery in a similar temperature range relative toT

ISSN:0887-624X    

DOI:10.1002/pola.1989.080270403

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractPreparation of four diols containing nucleic acid bases derived from 3‐(thymin‐1‐yl)propanoic acid (3‐TPA) and 3‐(uracil‐1‐yl)propanoic acid (3‐UPA), and the corresponding model polymers of polynucleotides with linear polyester backbone and nucleic acid base derivative as pendant side chains are described.N‐(1′,3′‐Dihydroxy‐2′‐methyl‐2′‐propyl)‐3‐(thymin‐1‐yl)propionamide (VIa, 3‐HMPTPA),N‐(1′3′‐dihydroxy‐2′‐methyl‐2′‐propyl)‐3‐(uracyl‐1‐yl)propionamide (VIb, 3‐HMPUPA) and their isomers,N(β,β‐dihydroxyethyl)‐3‐(thymin‐1‐yl)propionamide (VIIa, 3‐HETPA), andN‐(β,β‐dihydroxyethyl)‐3‐(uracil‐1‐yl)propionamide (VIIb, 3‐HEUPA) were synthesized through the selectiveN‐acylation of 2‐methyl‐2‐amino‐1,3‐propanediol and diethanolamine with 3‐TPA and 3‐UPA, respectively, by the active ester‐N‐hydroxyl‐1,4‐epoxy‐5‐cyclohexene‐2,3‐dicarboximide (HOEC) method. The resulting diols were polycondensed with active diamide of benzotriazole (HBT) such as 1,1′‐(isophthaloyl)bis‐benzotriazole (IPBBT), g

ISSN:0887-624X    

DOI:10.1002/pola.1989.080270404

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractCopolymers of 2,2,2‐trifluoroethyl methacrylate (TFEMA) andN‐p‐methoxyphenyl citraconimide (MCM) have been synthesized. TheTgvaries with composition reaching 150°C with 34% MCM. The copolymer has good radiation sensitivity according to bothGvalues for chain scission and E‐beam measurements. Though they have lower contrast than PMMA, they have much higher resistance to plasma etching. The resistance increases markedly with MCM content to values comparable to that for polyimides. Therefore, TFEMA–MCM copolymers of high MCM content can be useful as high temperature plasma etchable positive E‐

ISSN:0887-624X    

DOI:10.1002/pola.1989.080270405

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractIn a continuation of our effort on polyimides containing carbonyl and ether connecting groups between aromatic rings, several new polyimides were prepared and characterized. A few of these polymers were semi‐crystalline. Glass transition temperatures ranged from 164 to 258°C and crystalline melt temperatures were observed between 350 and 424°C. The semi‐crystalline polyimide from the reaction of 3,3′,4,4′‐benzophenonetetracarboxylic dianhydride and 1,3‐bis(4‐aminophenoxy‐4′‐benzoyl)benzene provided transparent orange films with excellent tensile properties, exceptional resistance to solvents and strong base, and high thermooxidative stability. In addition, this polyimide provided excellent adhesive strength for joining titanium

ISSN:0887-624X    

DOI:10.1002/pola.1989.080270406

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractFour 2,5‐biphenylene based difunctional condensation monomers, such as 2,5‐diphenyldicar‐boxylic acid or phenylterephthalic acid (PTA), 2,5‐bis(carbonylimino‐4‐benzoic acid)biphenyl (2,5‐BCIBABP), 2,5‐diaminobiphenyl hydrochloride (2,5‐DABP.HCl) and 2,5‐bis(iminocarbonyl‐4‐benzoic acid)biphenyl (2,5‐BICBABP), have been synthesized and characterized. These monomers were polymerized in combination with terephthalic acid (TA) andp‐phenylenediamine (PPD) via the phosphorylation reaction to prepare a series of phenyl‐substituted random copolyamides having all amide groups attached to para‐positions of the benzene rings. All the copolyamides have been characterized by solubility, solution viscosity, and by differential scanning calorimetry (DSC). Some of these copolyamides have unusual solubility in organic solvents such asN,N‐dimethylacetamide (DMAc) andN‐methyl‐2‐pyrrolidinone (NMP) containing dissolved lithium chloride. A few copolyamides were tested for lyotropic behavior and found to form anisotropic solutions at critical concentrations in organic solvents. A randomly distributed unsymmetrical phenyl substituent on the benzene ring of para‐oriented wholly aromatic polyamides dramatically changes the solubility and melting point. The phenyl substituent on a terephthalic acid unit is more efficient in decreasing melting point and increasing solubility in organic solvents of aromatic polyamides than the one on ap‐phenylenediamine unit. However, the former also introduces a more fl

ISSN:0887-624X    

DOI:10.1002/pola.1989.080270407

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractSi‐containing mono‐ and disubstituted polyacetylenes([CMeC(SiMe3)]n, [CHČH(nC5H11)SiMe3]n, etc.) underwent degradation in air; many of them exhibited relatively high yields of main‐chain scission (Gs>1). TheGsvalues for the polymers having a longn‐alkyl group were usually large (ca. 2). In contrast, no polymer degradation occurred in vacuum, indicating that oxygen is necessary for the radiolysis. The polymers irradiated in air contained CO and SiO groups, and dissolved in polar solvents, which are nonsolvents of the starting polymers. From the radiation sensitivity and thermal degradability of these polymers, it is concluded that disubstituted polymers with high Si contents ([CMeC(SiMe3)]n, [CMeC(SiMe2CH2SiMe3)]n, etc.) are not only radiation

ISSN:0887-624X    

DOI:10.1002/pola.1989.080270408

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe plasma polymerization of allylamine in an inductively coupled rf plasma reactor is analyzed by Fourier transform infrared spectroscopy. Comparison of the infrared spectra of the as‐received monomer and the plasma polymerized film reveals a conversion of the primary amine in the monomer (CH2NH2) to an imine (CHNH) and a nitrile (CN). Plasma polymerization of ethylenediamine yields the same results, suggesting that this polymerization scheme may be typical of primary amines. Increasing the plasma power seems to increase the proportion of nitrile groups in relation to the imine groups. The infrared spectra of the vapor phase polymerized monomer was similar to that of the substrate‐grafted allylamine film implying a similar structure. Aging of this vapor phase polymer at 120°C for 1 h in vacuum and at 295°C for 15 min in an oxygen free environment reveals nitrile group reaction similar to that observed in polyacrylonitrile. Thermogravimetric analyses of the vapor phase polymers in a nitrogen atmosphere at 20°C/min demonstrated the thermal stability, with the polymer produced at a plasma power level of 50 W retaining 20% of its weight at 1000°C. This was better than the stability shown by the polymer produced at 150 W and is attributed to the ease of nitrile group polymerizat

ISSN:0887-624X    

DOI:10.1002/pola.1989.080270409

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY

摘要:

AbstractNovel polypyrazolinones with inherent viscosities ranging from 0.12 to 0.44 dL/g were prepared by the Michael‐type nucleophilic addition‐cyclization of various dihydrazines with 3,3′‐(1,3‐ or 1,4‐phenylene)bis(ethyl propynoate) (1,3‐ or 1,4‐PEP) and 3,3′‐(1,4‐phenylene)bis(phenyl propynoate) (1,4‐PPhP) inN‐methylpyrrolidone (NMP) solution at 25–110°C. The polymers exhibited moderate thermal stability with initial weight loss in air about 200°C and in nitrogen about 300°C (TGA). No apparentTg′s were observed by DSC analysis. The synthesis and characterization of th

ISSN:0887-624X    

DOI:10.1002/pola.1989.080270410

出版商:John Wiley&Sons, Inc.    

年代:1989

数据来源: WILEY