In this research, the effect of the drawing process on the physical and thermal properties of commercially available polypropylene fiber containing selective peroxide was studied. Attempts have also been made to compare this drawn fiber sample with conventional polypropylene fibers produced from reactor and with controlled rheology grades. The results showed that the drawn PP/Peroxide fiber has higher birefringence, tenacity, and initial modulus compared with that of the drawn polypropylene fiber. Moreover, the fraction of load carrying chains in various drawn polypropylene fibers was evaluated on the basis of simplified models.

É apresentado um procedimento simples e geral para a condensação aldólica cruzada dupla de cetonas cíclicas com vários aldeídos aromáticos catalisada por dietilamina em condições aquosas. Foram obtidos 3,5-bisarilmetilidenos de cetonas homocíclicas e heterocíclicas em um procedimento one-pot em excelentes rendimentos. Além disto, a metodologia é aplicada eficientemente à síntese de chalconas a partir das metil cetonas correspondentes. Na maioria dos casos estudados, os produtos precipitam das misturas de reação e o meio é reciclado em várias reações subseqüentes sem perda significativa de atividade.

A facile and general procedure is presented for diethylamine-catalyzed double crossed aldol condensation of cyclic ketones with various aromatic aldehydes under aqueous conditions. Excellent yields of 3,5-bisarylmethylidenes of homocyclic and heterocyclic ketones are achieved in a one-pot procedure. Furthermore, the methodology is efficiently applied to the synthesis of chalcones from their corresponding methyl ketones. In the majority of the cases studied, products precipitate from the reaction mixtures and the medium is recycled in subsequent several reactions without significant loss of activity.