Polybutadiene block hydrogenated

Balsamo V, Lorenzo AT, Muller AJ, Corona-Galvan S, Fraga Trillo LM, Ruiz Santa Quiteria V. Structure properties and applications of ABA and ABC triblock copolymers with hydrogenated polybutadiene blocks. In Lazzari M, Liu G, Lecommandoux S, editors. Block Copolymers in Nanoscience. Weinheim, Germany Wiley-VCH 2006. p 367-389. 

For our experimental studies on polymer crystallization we used low molecular weight (Mw) poly(ethylene oxide) (PEO), either as a homopolymer or attached to an amorphous polystyrene or hydrogenated polybutadiene block. These block copolymers are abbreviated by PS-PEO and PB, -PEO, respectively. PEO is a weU-investigated polymer [5,19,36,37]. Molecular details of all investigated polymers are given in Table 1. 

Figure 11.3 Cover page of US Patent 3,431,323, with plots of apparent glass point and ball rebound with respect to % C2 side chain (parts a and b) and tensile strength with respect to % C2 side chain at 75 °C (part c) and 100 °C (part d). The % C2 side chain is equivalent to the 1-butene content in the hydrogenated polybutadiene block.

Hydrogenated SBS triblock polymers have become increasingly important (Kraton G by Shell). With the original polybutadiene block comprised of 65% 1,4-and 35% 1,2-structures the elastomeric central block is equivalent to that of a high-ethylene ethylene-butene rubber. 

B = B 4, 1,4-polybutadiene block Bj 2, 1,2-polybutadiene block B y, medium vinyl (35-60%) polybutadiene block) I, 1,4-polyisoprene block. Selective hydrogenation this block not hydrogenated. 

In this study, the effects of the variations in block sequence and composition (and thus relative block length) on the material properties of two series of triblock copolymers has been investigated. One of the blocks, the hydrogenated polybutadiene (HB), is semicrystalline, and the other block, the hydrogenated polyisoprene (HI) is rubbery at room temperature. Thus in one series, the HBIB block copolymers, the end blocks are semi-... 

Figure 4. Gel permeation chromatograms of a polystyrene/ polybutadiene block copolymer (SBD-4) Before hydrogenation and fractionation (lower) and after (upper).

Studies of polymers dissolved in various oils indicate general agreement, with the volume fraction exponent reported to be 2 to 2.3 (5,6). In a recent study, W.W. Graessley and co-workers (7) reported exponents of 2.22 and 2.26 for polybutadiene and hydrogenated polybutadiene in various diluents. G. Kraus and K.W. Rollmann (8) reported on the only study of resins as the polymer diluent. Using a styrene-isoprene-styrene block copolymer, they found exponents of 2.28 for the glycerin ester of stabilized rosin and 2.62 for a C -stream resin. Plateau modulus was identified as G in the rubbery plateau where tan 6 was a minimum in a temperature scan of the systems. 

Common SS include polyethers, polyesters and polyalkyl glycols with glass transition temperatures in the range of -70°to -30°C. Commonly used macrodiols in the PUs synthesis are polyalkyl-diols, such as polyisobutylene diol [70], polybutadiene (PBU) [20, 71], or oligo-butadiene diols [72] as well as hydrogenated polybutadiene diol [20] polyether diols polytetrahydrofuran (PTHF or PTMO) [50-52], polyethylene glycol (PEG) or (PEO) [73], polypropyleneoxide (PPO) [73] or mixed blocks of them PEO-PPO-PEO [74] and PPO-THF [54] polyester diols poly(ethylene adipate) (PEA) [4,20], poly(butylene adipate) (PBA) [20, 73], and latterly polycaprolactone diol (PCL or PCD) [75], polyalkylcarbonate polyol [20] or mixed blocks of them, for example poly(carbonate-co-ester)diol [76], poly(hexamethylene-carbonate)diol [77], as well as poly(hexamethylene-carbonate-co-caprolactone)diol [78] and a mixed block copolymer of polyether and polyester blocks PCL-b-PTHF-b-PCL [79]. Examples schemes of macrodiols are shown in Eig. 1.9. 

PP has been recycled from industrial scraps. The melt flow index was about 5.5. Kraton FG 190IX is a triblock copolymer consisting of polystyrene end-blocks and a partly hydrogenated polybutadiene mid-blocks grafted with maleic anhydride, and manufactured by Shell Chemicals. 

Kraton G is a SEES thermoplastic elastomer with a middle block of hydrogenated polybutadiene and molecular weight of about 64,000. Vistalon is an EPDM rubber with a molecrdar weight of about 278,000. Paraloid is a methylmethacrylate-butadiene-st3rrene, MBS, elastomer with a core-shell structure. 

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... 

Figures Scheme for the change of the morphological behavior of a polystyrene-block-polybutadiene-block-poly(methyl methacrylate) S-B-M induced by hydrogenation of B to poly(ethylene-co-butylene) EB from a lamellar morphology with B spheres or B cylinders between S and M lamellae in an S-B-M triblock terpolymer to a hexagonal morphology, where EB rings surround S cylinders in an M matrix after hydrogenation.

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