Butadienes solid-state

Styrene-butadiene rubber (SBR) is the most widely used synthetic rubber. It can be produced by the copolymerization of butadiene (= 75%) and styrene (=25%) using free radical initiators. A random copolymer is obtained. The micro structure of the polymer is 60-68% trans, 14-19% cis, and 17-21% 1,2-. Wet methods are normally used to characterize polybutadiene polymers and copolymers. Solid state NMR provides a more convenient way to determine the polymer micro structure. ... 

Chloranil, photocycloaddition with butadiene, 474 Chlorophylls, 552 Chu, N. Y. C 439 Ciamician, G., 1, 2,459 Cinnamic acid, solid state photodimerization, 476... 

The reaction can be carried out via the preliminary isolation of 15 or it can be performed in situ with the corresponding Mg-butadiene derivative. In the solid state, the bonding mode of the butadiene ligands in both complexes 43 and 44 can be described as tt2, t 4. A variety of bonding modes of butadiene to zirconium ranging from tt2, t)4 to a2, tt, t 4 can be found in complexes having subunits other than... 

The dynamic mechanical behavior indicates that the glass transition of the rubbery block is basically independent of the butadiene content. Moreover, the melting temperature of the semicrystalline HB block does not show any dependence on composition or architecture of the block copolymer. The above findings combined with the observation of the linear additivity of density and heat of fusion of the block copolymers as a function of composition support the fact that there is a good phase separation of the HI and HB amorphous phases in the solid state of these block copolymers. Future investigations will focus attention on characterizing the melt state of these systems to note if homogeneity exists above Tm. 

Later, Tieke reported the UV- and y-irradiation polymerization of butadiene derivatives crystallized in perovskite-type layer structures [21,22]. He reported the solid-state polymerization of butadienes containing aminomethyl groups as pendant substituents that form layered perovskite halide salts to yield erythro-diisotactic 1,4-trans polymers. Interestingly, Tieke and his coworker determined the crystal structure of the polymerized compounds of some derivatives by X-ray diffraction [23,24]. From comparative X-ray studies of monomeric and polymeric crystals, a contraction of the lattice constant parallel to the polymer chain direction by approximately 8% is evident. Both the carboxylic acid and aminomethyl substituent groups are in an isotactic arrangement, resulting in diisotactic polymer chains. He also referred to the y-radiation polymerization of molecular crystals of the sorbic acid derivatives with a long alkyl chain as the N-substituent [25]. More recently, Schlitter and Beck reported the solid-state polymerization of lithium sorbate [26]. However, the details of topochemical polymerization of 1,3-diene monomers were not revealed until very recently. 

Very recently, MacGillivray et al. succeeded in the supramolecular construction of molecular ladders in the solid state using a linear template approach [48]. They designed the cocrystals 1,3-benzenediol (resorcinol) or a derivative with an all-trans-bis(4-pyridyl)butadiene or hexatriene, in which two resorcinol molecules preorganize two polyene molecules through two hydrogen bond interactions, for [2-1-2] photoaddition (Scheme 5). In this design, two polyenes would... 

Lauher and Fowler et al. have proposed an elegant strategy for the control of topochemical polymerization based on the host-guest cocrystal concept. They used the ureylene and oxalamide functionality to form layered supramolecu-lar structures for the topochemically controlled polymerization of diacetylenes and 1,3-butadienes in the solid state [62,63]. 

While both solution and solid-state NMR has been routinely applied to polymers for many years, there have been a few recent applications of HRMAS to polymer systems, analyzing polymerization mechanisms and characterizing the resulting polymers in the swollen state. The vulcanization of butadiene rubber by cyclic disulfides was shown to follow two different mechanisms with two different classes of sulfur compounds - cross-linking progressed... 

R. Hulst, R. M. Seyger, J. P. M. van Duynhoven, L. van der Does, J. W. M. Noordermeer and A. Bantjes, Vulcanization of butadiene rubber by means of cyclic disulfides. 2. A 2D solid state HRMAS NMR study on cross-link structures in BR vulcanizates, Macromolecules,... 

Condensation of manganese and butadiene followed by addition of CO at -196°C gives a very low yield of Mn(C4H6)2CO (40). However, iron reacts quite efficiently and affords a red-brown complex that decomposes at about -5°C in the solid state ... 

Solid-state 13C NMR has been used to identify elastomers in binary blends of chloroprene (CR) and NR, CR and CSM, NR and CSM, and SBR and acrylonitrile-butadiene rubber (NBR). The type of NBR can be determined by identifying the sequences of acrylonitrile and butadiene. The tertiary blend of NR/SBR/BR was also studied [49]. High-temperature 13C solid-state NMR identified ethylene-propylene diene terpolymer (EPDM) and fluoro and nitrile rubbers [50]. 

Vulcanised SBR/EPDM diblends were quantitatively characterised by solid-state 13C NMR spectroscopy. The SBR/EPDM blend ratio can be determined as well as the czs-1,4, transit and vinyl-1,2 butadienes and styrene ratios in the SBR and the ethylene and propylene contents in the EPDM. No evidence for homo- and co-vulcanisation has been obtained in these systems. No evidences are found for the change in cisitrans ratio in the SBR upon the vulcanisation [52],... 

ID IQ 2D 2D-NMR 2h2o 2Q 3Q 9BEN A1 ABS AC ACM ACN AFM Al-CSM ALMA-i5 Al-m-EPDM AN AO APT ASTM ATR ATR-IR B/S BABA Two-dimensional Single-quantum One-dimensional Deuteron solid-state NMR Deuterated water Double-quantum Triple-quantum 9 borobicyclo [3, 3, 1] nonane Amide 1 Acrylonitrile-butadiene-styrene terpolymer Accelerator Acrylate rubber Acrylonitrile Atomic Force Microscopy Aluminium salt of chlorosulfonate polyethylene Allyl-rf5 methacrylate Aluminium salt of maleated EPDM Acrylonitrile 1-Allyl oxyoctane Attached Proton Test American Standards for Testing and Materials Attenuated total reflectance spectroscopy Attenuated total reflectance-IR spectroscopy Butadiene/styrene Back-to-back... 

By way of an early example, the effect of calcium carbonate, ATH, and MH fillers on smoke production from styrene butadiene (SBR) foams has been reported.47 It was evident that all the fillers reduced soot formation relative to unfilled foam with the hydrated fillers being more effective than the calcium carbonate, which was considered to act merely as matrix diluent. ATH and MH were found to give enhanced char formation with the promotion of solid-state cross-linking as opposed to pyrolytic degradation. An afterglow effect, occurring after the extinction of the flame, was noted with MH and attributed to the slow combustion of carbon residues. 

Estimate the free enthalpy of polymerisation of 1,3-butadiene to polybutadiene (1 4) when the monomer is in the liquid state and the polymer is in the amorphous solid state. 

In contrast to its ready reaction with acetylenes, Cp2Mo2-(CO)i+ does not react with simple olefins or dienes, e.g., C2Ht+, butadiene, C2H3CN, norbornadiene, etc. With TONE (C2(CN)iJ, 1 is oxidized and [CpMo(C0)il]+ [TONE]7 may be isolated (6). Allene does react, however, to form a complex, ll, in which each of the orthogonal C=C n-bonds donates two electrons to each molybdenum. This fluxional molecule has C2 symmetry in the solid state and has a Mo-Mo bond length of 3.117(1)A (32). 

The complexes W( " -diene) (CO)6-2 (n = 2, diene = 1,3-butadiene, (83) n = 3, diene = 2,3-dimethylbutadiene, 84) have been prepared, and their solid-state molecular structures have been determined. Interestingly, the two diene ligands in (83) are twisted relative to one another, imparting C2 symmetry to the complex. Homoleptic (84) lias been the subject of a detailed theoretical investigation in an attempt to explain its rare trigonal-prismatic coordination... 

Attansai et al have reported the first general protocol for the preparation of polymer-bound 1,2-diaza-1,3-butadienes (93) and demonstrated their utility in the solid state synthesis of 4-triphenylphosphoranylidene-4,5-dihydropyrazol-5-ones (94) (Scheme 17). ... 

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