Comparison of phase structures and surface free energy values for the coatings synthesised from linear polyurethanes and from waterborne polyurethane cationomers

WAXS, DSC and AFM methods were employed to compare phase structures of the coatings obtained from waterborne polyurethane cationomers which had been synthesised in the reaction of some diisocyanates (MDI, IPDI, TDI and HDI) with polyoxyethylene glycols (M = 600 and 2,000) and butane1,4-diol or N-methyl- or N-butyldiethanolamine and 2,2,3,3-tetrafluoro-1,4-butanediol. The structures were also analysed of the coatings derived from linear polyurethanes which had been synthesised on the basis of similar raw materials. Better rigidity was found for generally amorphous cationomer coats. Changes were discussed in the surface free energy (SFE) values and in their components, as calculated independently with the use of the van Oss–Good and Owens–Wendt methods. Polyurethane coats turned out more hydrophobic as compared to cationomer ones. In both coat types, fluorine incorporated into cationomers contributed to lower SFE values: from 50 down to about 30 mJ/m2

Use of Library Resources by Staff and Students of Secondary Schools in Umuahia North Local Government Area of Abia State

Use of library resources by staff and students of secondary schools in Umuahia North Local Government Area was investigated and analyzed, in order to determine the collections of these libraries the use made of them as well as determine whether or not these resources satisfy the information needs of both staff and students. The survey research method was adopted using simple random sampling techniques to select actual respondents from the population. The design is a case study and the major instrument for data collection was the questionnaires complemented by documentary sources and direct observations. Results indicate among other things that staff and students make use of these libraries but the library resources do not satisfy he information needs of respondents results also indicate that lack of current and up-to-date materials is the most prominent factor militating against library use. It is recommended that adequate funds should be provided to procedure current materials

Palaeocological study of microbiota from the Ameki Formation (Eocene) : Southeastern Nigeria

Arua I. Palaeocological study of microbiota from the Ameki Formation (Eocene) : Southeastern Nigeria. In: Géologie Méditerranéenne. Tome 11, numéro 1-2, 1984. C.A.M. IXe colloque africain de micropaléontologie. Paris, Museum d'Histoire Naturelle, du 3 au 6 octobre 1983. p. 132

Palaeocological study of microbiota from the Ameki Formation (Eocene) : Southeastern Nigeria

Arua I. Palaeocological study of microbiota from the Ameki Formation (Eocene) : Southeastern Nigeria. In: Géologie Méditerranéenne. Tome 11, numéro 1-2, 1984. C.A.M. IXe colloque africain de micropaléontologie. Paris, Museum d'Histoire Naturelle, du 3 au 6 octobre 1983. p. 132