摘要:

A critical concentrationC*is identified at which interaction or overlapping of the domains of polymer molecules in solution first occurs. Thirty-three experimental values ofC*from eight different systems, drawn from 10 literature sources and using seven different detection procedures, were correlated with an average absolute deviation of 22.1%. The correlation is particularly useful because, in contrast to other procedures, it requires no physical measurements and involves a new application of molal volume estimates from standard tabulations. Extension of the study to wider ranges of polymer and solvent types is advocated.

ISSN:0360-2559    

DOI:10.1080/03602559608000608

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Homogeneous photoinduced graft copolymerization of 4-vinyl pyridine (4-VP) onto ethyl cellulose (EC) in the presence of three photosensitizers such as 1-acetonaphthone (1-An), 2-acetonaph-thone (2-An), and biacetal (Bi) in benzene solution was extensively investigated. Ultraviolet (UV) irradiation in the range 310 to 460 nm was used. The U V spectra of the mentioned photosensitizers showed n-π*transitions. Grafting parameters such as grafting percentage (GP) and grafting efficiency (GE) were determined as functions of the irradiation time and the concentrations of monomer, substrate, and initiator. The IR spectrum of the EC-g-4-VP copolymer shows the appearance of new peaks between 1600 and 1690 cm-1indicating the presence of poly-4-vinyl pyridine (p-4-VP) grafted chains. The rate of copolymerization of 4-VP onto EC in the presence of 1-An, 2-An, and Bi was determined as 0.98% min-1, 0.88% min-1and 0.042% min-1, respectively.

ISSN:0360-2559    

DOI:10.1080/03602559608000609

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

Wood-plastic composite was prepared under Co-60 gamma irradiation with kadom (Anthrocephalus) (d= 0.36 g/cm3), a soft wood of Bangladesh, and methylmethacrylate (MMA) combined with methanol in the presence of a number of organic and inorganic acids. The impregnation was made at normal conditions. Polymer loading was determined and the change of tensile and bending strengths as a result of acid was evaluated. Most of the acids decrease both tensile and bending strengths, but adipic and oxalic acids do increase both the strengths.

ISSN:0360-2559    

DOI:10.1080/03602559608000610

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

摘要:

It is a time-consuming task to develop models or empirical equations which would accurately predict fluid properties of polymers as a function of chemical constitution and other experimental variables. Consequently, extensive experimental data have been published in the literature. When such experimental data are available, considerable time can be saved by the use of artificial neural network (ANN) technique based model approaches. Even though these ANNs have been in existence for a long time, their use in predicting fluid properties is still rather limited. In this paper, an attempt has been made to predict the fluid properties of different siloxanes as a function of their molecular configurations with the aid of ANN.

ISSN:0360-2559    

DOI:10.1080/03602559608000611

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor

ISSN:0360-2559    

DOI:10.1080/03602559608000612

出版商:Taylor & Francis Group    

年代:1996

数据来源: Taylor