Resinous substances

Ester plasticizers are used mainly in very polar elastomers, such as neoprene and nitrile mbber, to improve low or high temperature performance or impart particular oil or solvent resistance to a compound 5—40 parts are commonly used (see Plasticizers). Resins and tars are added to impart tack, soften the compound, improve flow, and in some cases improve filler wetting out, as is the case with organic resins in mineral-filled SBR. Resinous substances are also used as processing agents for homogenizing elastomer blends. 

Pitch Control. Resinous constituents of wood cause problems in paper machines by sticking to the rollers and causing spots or holes in the paper the worst cases cause paper webs to mpture. Costly stoppages, wastages, and quaUty problems because of these resinous substances can be avoided by using Upases (84). 

Harz-saure, /. resin acid, resinic acid, -aeife, /. resin soap rosin soap, -sikkativ, n. rosin drier, -spiritus, m. rosin spirit, -spur, /. trace of resin or rosin, -stippe, /. (Paper) rosin speck, rosin spot, -stoff, m. resinous substance, -talgseife, /. tallow-rosin soap, yellow household soap, -tanne, /. pitch fir. -teer, m. resinous tar. -wasser, n. resin water, -zahl,/. resin number rosin number, -zement, m. resinous cement, haschen, v.t. tk i. eatch, seize, haschieren, hatch hash, mince. 

In oxidizing, oil becomes thicker and it deposits carbon and gummy, resinous substances. These accumulate in the piston-ring grooves of reciprocating compressors and in the slots of vane-type units, and as a result, they restrict free movement of components and allow air leakage to develop. The deposits also settle in and around the valves of piston-type compressors, and prevent proper sealing. 

Cowan Teeter (1944) reported a new class of resinous substances based on the zinc salts of dimerized unsaturated fatty acids such as linoleic and oleic acid. The latter is referred to as dimer acid. Later, Pellico (1974) described a dental composition based on the reaction between zinc oxide and either dimer or trimer acid. In an attempt to formulate calcium hydroxide cements which would be hydrolytically stable, Wilson et al. (1981) examined cement formation between calciimi hydroxide and dimer acid. They found it necessary to incorporate an accelerator, alimiiniiun acetate hydrate, Al2(OH)2(CHgCOO)4.3H2O, into the cement powder. 

Cowan, J. H. Teeter, H. M. (1944). Salts of residual dimerized fat acids a new class of resinous substance. Industrial and Engineering Chemistry, 36, 148-52. 

The techniques of paraffin removal and paraffin prevention have been reviewed [810]. In particular, inhibitors for paraffin deposits are copolymers of ethylene with vinylacetate [525-527,1597] or polymers from p-nonylphenyl methacrylate and p-dodecylphenyl methacrylate [773]. These materials lower the pour point of the oil. It has been shown that for oils which differ in the content of n-paraffins and asphalt-resinous substances, it is necessary to use blends of copolymers of different compositions and molecular weights to obtain optimal efficiency. Polyacrylamide and wastes from the production of glycerol with a concentration of 400 mg/liter of oil have also been claimed to be effective as paraffin inhibitors [536]. 

E. Ribechini, F. Modugno, M.P. Colombini, Direct exposure (chemical ionization) mass spectrometry for a rapid characterization of raw and archaeological diterpenoid resinous substances, Microchimica Acta, 162, 405 413 (2008). 

A. M. Pollard and C. Heron, The chemistry and use of resinous substances, in Archaeological Chemistry, RSC Paperbacks, Cambridge, 1996. 

The results obtained for these four samples highlighted the usefulness of SPME to get complementary information allowing a better characterisation of resinous substances. It is indeed possible to detect many non degraded mono- and sesquiterpenes in well preserved samples such as samples 1480 and 1485 and to detect some characteristic compounds in degraded samples such as sample 1484. 

SPME/GC/MS is an efficient technique to reveal the presence of resinic substances in archaeological samples. Indeed, volatile terpenes are still present in very old archaeological samples (4000 years old), particularly in the case of compact matrixes, and can be trapped by the SPME fibre. In comparison with methylene chloride extraction, SPME is very specific and allows the direct analysis of the volatile terpenes content in complex mixtures including oils, fats or waxes. For this reason, headspace SPME is the first method to use when analysing an archaeological sample it will either allow the identification of the resin or indicate further sample treatment in order to detect characteristic triterpenes. The method is not really nondestructive because it uses a little of the sample but the same sample can be used for several SPME extractions and then for other chemical treatments. 

The generic name of a series of raw materials made by intimate mixture or chemical combination of natural mbber and other polymeric or resinous substances. 

Combination with oxygen. On the basis of the electronic theory of valency the meaning of the term has been extended to include all reactions in which there occurs an increase in the ratio of the electronegative to the electropositive atoms or groups of a substance. The controlled oxidation of natural rubber produces resinous substances called Rubbones. 

The trade name for a variety of resinous substances produced by the oxidation of mbber. Rubbones, designated A, B and C depending on the degree of oxidation, were once used in certain... 

Extractives of resinous materials by a hydrocarbon type solvent. The extractives are both volatile and non-volatile materials, and the resinous substance used is non-cellular in nature, e.g. Olibanum resinoid. 

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