Preparation, sample, poly

Other lignins can be reacted with this chemistry. Table 7 shows synthesis data for the preparation of poly(lignin-g-(1-amido-ethylene)) from several different lignins. Sample 1 is a kraft pine lignin grafted in a reaction coinitiated with sodium chloride. 

Materials and Solution Preparation. The poly( 1-amidoethylene) used in all experiments was a molecular weight standard supplied by Polysciences, Inc., as material 8249, batch 93-5. The polymer was dried for 3 hr. under a vacuum of < 10 Pa at a temperature of 25°C. The polymer was dispersed on a vortex of 0.01 M Na2S04 solution and stirred for 1 day. The solution was then centrifuged to remove undissolved polymer particles and the preweighed centrifuge tube was dried and reweighed. The polymer concentration of the master sample was calculated from the weight of polymer retained in the solution. The concentration of the master sample was 2,115 ppm or 0.2115 g/dL. 

Preparation of Poly(p-formyloxystyrene) (IV) A sample formyloxystyrene and 0.0652 g AIBN were combined in a bottomed flask equipped with an air cooled condenser and N2 bubbler, and heated at 80 C overnight. The resulting polymeric mass was dissolved in THF and precipitated in petroleum ether. Repeated washing, followed by drying of the polymer overnight in a vacuum oven at room temperature yielded 4.85 g (79%) of poly(/>-formyloxystyrene) (M = 1.09 x 104, Mz = 1.65 x 104, polydispersity =1.51 (gpc)). 

Poly(B-vinylborazine) is an air-sensitive white solid. Lightly cross-linked, freshly prepared samples are soluble and thermally stable in most dry aprotic solvents, such as benzene and ethers. If stored as a solid at room temperature, the polymer may become insoluble in several hours, but in benzene or glyme solution it is stable and can be used as a stock solution. The polymer decomposes rapidly in contact with water and alcohols. 

Harrison [4] prepared poly(isobutylene-g-succinic anhydride) by reacting a 1 1 mole ratio of polyisobutene/maleic anhydride using di-t-butylperoxide as catalyst where the ratio of di-t-butylperoxide/polyisobutene was 0.05 1, respectively. In this procedure polyisobutylene had a Mn of roughly 2300 daltons while the product had a SAP number of 26.2 mg for the KOH/g sample. Poly (isobutylene-g-succinic anhydride) has also been prepared in the simultaneous chlorination/maleation process described by Barini [5]. 

Polymers and copolymers were laboratory-prepared samples. Samples W4 and W7 of the diblock copolymer AB poly(styrene-fo-tetramethylene oxide) (PS—PT) were synthesized by producing a polystyrene prepolymer whose terminal group was transformed to a macroinitiator for the polymerization of THF. Samples B13 and B16 of the diblock copolymer AB poly[styrene-h-(dimethyl siloxane)] (PS-PDMS) were prepared by sequential anionic polymerization. Samples of statistical copolymers of styrene and n-butyl methacrylate (PSBMA) were produced by radical copolymerization. Details of synthetic and characterization methods have been reported elsewhere (15, 17-19). 

Fig. 4. Thermal desorption spectra for 11-MUA form Au(lll)/mica and poly crystalline gold foil, respectively, shown for freshly prepared samples (a) as well as for samples which were kept under ambient conditions for one month (b).

Polymer materials possess varying physical and structural properties dependent upon the route of synthesis and polymerization, as was discussed in Section 4.1. Properties also depend upon their actual physical form or state. The as prepared samples obtained by chemical polymerization are in the state of powder. Polymer films are prepared by dissolving the powder in an appropriate organic solvent and then letting the solution dry by slow evaporation. Common solvents with poly(alkylthiophene)s are chloroform, tetrachlormethane, toluene, tetrahydrofuran, decaline, anisole, thiophene and some others, whereas acetone. 

Instrumentation. In studies reported so far [84], polymer nanocomposites as used in lithium batteries prepared from poly(ethylene oxide) and lithium hectorite have been investigated. Using a sample holder that could be heated, structural changes of the nanocomposites as a function of temperature could be monitored in situ. Ex situ studies of electrodeposited amorphous NiP coatings have been described [85]. 

Hoteling, A.J., Mourey, T.H., and Owens, K.G. (2005) Importance of solubility in the sample preparation of poly(ethylene terephthalate) for MALDI-TOF MS. Anal. Chem., 77, 750-755. 

Phase Continuity in Sequentiai iPNs. The question has been repeatedly raised Do IPN morphologies really exhibit dual phase continuity Evidence for dual phase continuity in sequential IPNs was examined by Widmaier and Sperling (40,41). A series of sequential IPNs were prepared from poly(ra-butyl acrylate) and polystyrene. Two cross-linkers were used, divinyl benzene (DVB), which forms ordinary covalent cross-links, and aciyUc anhydride (AA), which forms labile crosslinks. The AA cross-links were cut by soaking the samples in a 10% aqueous ammonium hydroxide solution for about 12 hours. 

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