Copolymers, containing poly butylene studies

Having established the rates and types of motion that occur in the poly (butylene terephthalate) homopolymer (5), it is of interest to extend these studies to the investigation of the types of motions that occur in segmented copolymers that contain poly (butylene terephthalate) as the hard segment. The structure of such a polymer is shown below, where m and n refer to the "hard" and "soft" segments, respectively. (This structure also illustrates the sites of the deuterium labels.)... 

Breiner et al. (36) studied the so-called knitting pattern found for the triblock copolymer polystyrene-h/ock-poly(ethylene-5 tot-butylene)-h/c c -poly(methyl methacrylate) see Figure 13.17. [The poly(ethylene-5 tflt-buty-lene)-component was formed by hydrogenating the original polybutadiene block, which contained some 1,2-placements as well as the more usual 1,4-placements.] In this morphology, poly(methyl methacrylate) forms peristaltic lamellae in which opposite maxima and minima are spanned by ellipsoidalshaped cylindrical poly(ethylene-co-butylene). Of course, such complexity arises from the combined need of the chains to be able to wander from domain... 

Materials. Nanocomposites from metallocene polypropylene (HM562S, Lyondell-Basell) and nanoclay (hydrophilic montmorillonite, MMT) are studied. The MMT is obtained from Laviosa Chimica Mineraria, Italy (3.8 wt.-% aq. dispersion of montmorillonite). A compatibilizer is added to two of the materials in order to intercalate the MMT. The compatibilizer is an amphiphilic block copolymer (ABC) made by atom-transfer radical polymerization (ATRP) [3, 4]. It consists of a hydrophobic block of hydrogenated polybutadiene, i.e. poly(ethylene-co-1,2-butylene) monoalcohol (trade name Kraton L-1203 from Kuraray Co., Japan) with molecular weight 7000 and PDI = 1.05, and a hydrophilic block of quaternized dimethylaminoethyl methacrylate. Modified nanoclays with 4.7 and 8.0wt.-% of the ABC have been prepared. Table2.1 describes the composition of the studied materials. Sample PP is the pure polypropylene. Sample PP+MMT is a blend of polypropylene and the freeze-dried hydrophilic MMT. The samples PP+lcMMT and PP+hcMMT are composites that contain MMT with low compatibilizer amounts and high compatibilizer amounts, respectively. In order to prepare the nanocomposites, modified IcMMT and hcMMT have first been freeze-dried and, second, blended" with the PP. 

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