Molecular weight reduced

Phenolic resin substantially increases open time and peel strength of the formulation (80). For example, higher methylol and methylene ether contents of the resin improves peel strength and elevated temperature resistance. Adhesive properties are also influenced by the molecular weight distribution of the phenoHc low molecular weight reduces adhesion (82). 

Plasticizers can be classified according to their chemical nature. The most important classes of plasticizers used in rubber adhesives are phthalates, polymeric plasticizers, and esters. The group phthalate plasticizers constitutes the biggest and most widely used plasticizers. The linear alkyl phthalates impart improved low-temperature performance and have reduced volatility. Most of the polymeric plasticizers are saturated polyesters obtained by reaction of a diol with a dicarboxylic acid. The most common diols are propanediol, 1,3- and 1,4-butanediol, and 1,6-hexanediol. Adipic, phthalic and sebacic acids are common carboxylic acids used in the manufacture of polymeric plasticizers. Some poly-hydroxybutyrates are used in rubber adhesive formulations. Both the molecular weight and the chemical nature determine the performance of the polymeric plasticizers. Increasing the molecular weight reduces the volatility of the plasticizer but reduces the plasticizing efficiency and low-temperature properties. Typical esters used as plasticizers are n-butyl acetate and cellulose acetobutyrate. 

The Cu(II)/Cu(I) redox system added as bromide has recently been used to prepare well-defined polymers (controlled molecular weight, reduced poly-dispersity, terminal functionalities). One of the most successful methods to make well-defined polymers is atom transfer radical polymerisation (ATRP)18 ... 

The dependence of the Kerr constant on molecular weight (reduced chain length x) during the corresponding change in tlw conformation of the molecule from the straight rod to the Gaussian coil is depicted by Eqs. (97) or (100) ... 

In an attempt to account for the eventual production of low molecular-weight reducing sugars from starch by B. macerans amylase action, Cramer and Steinle propose the following scheme. ... 

Thus, Hope and his coworkers concluded for the solid-state extrusion of linear poly-ethylenes that increasing the molecular weight reduced both the maximum degree of deformation and the tensile properties of the product. Hie solid-state extrusion of copolymers, on the other hand, increased the maximum degree of deformation. The degree of stiffness enhancement upon extrusion and the melting points of the products were reduced. 

The iron storage protein ferritin has a MW = 700,000 with a Fe core buried in a thick protein shell across which electrons cannot tunnel, in contrast to low-molecular weight reducing agents (FADH2). After preparation of the core, one reduction step was measured at -0.38 V (SCE) in 0.01 MHCl solution by normal pulse polarography. 

If bimolecular termination is predominant, then the instantaneous average molecular weights reduce to ... 

Poly(vinyl alkyl) ethers were obtained as follows Poly(vinyl ethyl ether) - EDBC from Union Carbide. This material is relatively low in molecular weight (reduced viscosity 0.3 + 0.1 in benzene, 0.1 gm/100 ml at 20 C) and contains 0.5% monotertiary butyl hydroquinone stabilizer. It consists of 98% nonvolatiles. In some cases, PVEE, manufactured by BASF-Wyandotte, was used (A-25 and A-50 with reduced viscosities of 0.07 and 0.66 respectively in... 

The traditional technique for sulphonylation with sulphonyl chlorides uses at least one mole of Friedel-Crafts halide per mole of sulphonyl chloride and it was realised that this would lead to difficulties in isolating polymers free from inorganic contaminants. However, the preparation of monomeric sulphones using catalytic quantities of FeCl had been reported in a war-time German patent [12] and we applied this procedure to reactions (1). Polymers of high molecular weight (reduced viscosity, RV, up to 1.2 for 1% solutions of polymer in dimethyl formamide at 25 C) were obtained... 

Monomer conversion, evolution of molecular weight, reduced viscosity, and rate constants were assessed in Reference [65] in the case of the NMP of BA using A-tertiobutyl-1 -diethylphosphono-2,2-dimethylpropyl nitroxide (SGI). The reactions were carried out using both monocomponent (alkoxyamines with or without free SGI) and bicomponent (AlBN+free SGI) initiators. 

With monoalkyl-aluminum dichloride, on the other hand, no reduction occurs at room temperature and below. The catalyst remains in solution and in the presence of ethylene oligomer is formed. Evidently, the relatively low electrmi density at the Ti(IV) center (high electron affinity, high acidity, or however one wishes to express the situation) favors the molecular weight-reducing -hydrogen abstraction, Eq.(2). Not only the valency of the titanium ion itself, but also the presence of the acceptor ligands Cl at the titanium center and at the aluminum alkyl contribute to the acidity of the catalyst center. 

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