Layered adipate-modified

Prepare 26 g. of molecular sodium in a 1500 ml. round-bottomed flask (Section II,50,d, Method 1). Cover the sodium with 625 ml. of sodium-dried A.R. benzene fit the flask with an efficient reflux condenser protected from the air by means of a calcium chloride (or cotton wool) guard tube. Add 151 5 g. of diethyl adipate (Sections 111,99 and 111,100) in one lot, followed by 1 6 ml. of absolute ethyl alcohol. Warm the flask on a water bath until, after a few minutes, a vigorous reaction sets in and a cake of the sodio compound commences to separate. Keep the flask well shaken by hand during the whole of the initial reaction. After the spontaneous reaction has subsided, reflux the mixture on a water bath overnight, and then cool in ice. Decompose the product with ice and dilute hydrochloric acid (1 1) add the acid until Congo red paper is turned blue. Separate the benzene layer, and extract the aqueous layer with 100 ml. of benzene. Wash the combined extracts with 100 ml. of 5 per cent, sodium carbonate solution and 160 ml. of water dry over a KWe anhydrous magnesium sulphate. Remove the benzene under atmospheric pressure (Fig. II, 13, 4, but with modified Claisen flask), and fractionate the residue under reduced pressure. Collect the 2-carbethoxy-epelopentanone at 108-111°/15 mm. (96 g.). Upon redistillation, the product boils at 102°/H mm. 

Copolymers of PBS and butylene adipate, PBSA, have been largely used to prepare bionanocomposites [338-343]. Ray and Bousmina [338] prepared PBSA/layered silicate nanocomposites by melt extrusion of PBSA and commercially available OMMT. They showed that increasing the level of interactions (miscibihty) between the organic modifier and PBSA matrix, increased the tendency of the sihcate layers to delaminate and distribute nicely within the PBSA matrix. Thermal analysis revealed that the extent of crystallinity of PBSA matrix was directly related to the extent of exfoliation of silicate layers in the nanocomposites and DMA and tensile property measurements showed concurrent improvement in mechanical properties when compared to the neat PBSA and the extent of improvement is directly related to the extent of delamination of silicate layers in the PBSA matrix. DMA also revealed remarkable increase in flexural storage modulus when compared with that of neat PBSA. Tensile properties were also improved with nanoclay addition [339], therefore in agreement with other studies reported in the literature for similar systems [344-347]. 

Shahlari M, Lee S. Mechanical and morphological properties of poly(butylene adipate-co-terephthalate) and poly(lactic acid) blended with organically modified silicate layers. Polym Eng Sci 2012 52(7) 1420-8. 

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