Residual odor

It is unlikely that two odors when combined will cancel each other and result in no odor, ie, 1 + 1 = 0 there is always some residual odor. However, reduction of an odor by an oxidation process can destroy the odor molecule permanently and leave no residual odor. 

In general, rubber manufacturers balance thiol reactivity and odor. The stmcture of the thiol plays a significant role in its abiUty to be transported within the polymer matrix, particularly in emulsion polymerizations, ie, mixed water—monomer emulsion. The odor of light thiols is generally too strong for most mbber manufacturers, as it is generally hard to remove residual odors from polymers. 

There is no specific color or other reaction by which methyl chloride can be detected or identified. QuaUty testing of methyl chloride for appearance, water content, acidity, nonvolatile residue, residual odor, methanol, and acetone is routinely done by production laboratories. Water content is determined with Kad Fischer reagent using the apparatus by Kieselbach (55). Acidity is determined by titration with alcohoHc sodium hydroxide solution. The nonvolatile residue, consisting of oil or waxy material, is determined by evaporating a sample of the methyl chloride at room temperature. The residue is examined after evaporation for the presence of odor. Methanol and acetone content are determined by gas chromatography. 

There are many chemicals, by lowering suitable as carriers. Their bp is one of the principal criteria in selection. If bp is too low, the compound will evaporate from the dyebath at dyeing temperatures, and will be lost before it is effective in its role as a carrier. It may also steam distill (condense on the cooler parts of the equipment) and cause drips that will spot the fabric. On the other hand, if the bp is too high, the compound cannot be removed from the fabric under normal plant drying conditions and will affect lightfastness of finished goods, leave residual odor, and possibly cause skin irritation to the wearer. 

Most carrier-active compounds ate based on aromatic chemicals with characteristic odor. An exception is the phthalate esters, which are often preferred when ambient odor is objectionable or residual odor on the fabric caimot be tolerated. The toxicity of carrier-active compounds and of their ultimate compositions varies with the chemical or chemicals involved. The environment surrounding the dyeing equipment where carriers are used should always be weU-ventilated, and operators should wear protective clothing (eg, mbber gloves, aprons, and safety glasses or face shields, and possibly an appropriate respirator). Specific handling information can be obtained from the suppHer or manufacturer. 

Odor. Det odor in accordance with ASTM D1296. In this test strips of filter paper are dipped into specimen and reference standards, and odor comparisons are made of characteristic odor when the strips are wet, and residual odor remaining after the strips appear dry. If an odor persists on the sample paper after the point in time when no odor is detectable on the standard paper, the odor is reported as residual ... 

Plants, fruits, vegetables, and grains should be washed thoroughly with soap and water and aerated to remove residual odor. 

The topmost layer of unprotected feedstock (e.g., hay or grain) should be destroyed. The remaining material should be aerated to remove residual odor. 

Gurnell, J. and Little, J. (1992). The influence of trap residual odor on catching woodland rodents. Animal Behaviour43,623-632. 

Odor — shall have characteristic "banana oil odor and shall leave no residual odor when tested accdg to FedTestMethodSrd No 141a, Method 4401, Sept I, 1965 Procedure Note the odor immediately upon opening the container. In addition, dip a strip of heavy filter paper (Whatman No 2 or equal) into container with EtAcet and hang the test strip on a suitable support. Place it in... 

In the manufacturing process of most polymers, there is a need to separate and remove undesirable, residual volatile components such as solvents, monomers, and other low molecular weight components from the polymeric material. These volatiles are removed in one or more postreactor operations in order to recover the solvent and monomer, impart the polymer with the desired physical properties, meet environmental requirements, and eliminate residual odors and taste. In condensation polymerization, of course, the removal of volatiles is essential to drive the polymerization reaction and reach high molecular weights. Moreover, removal of volatiles, moisture and entrapped air is also essential for many types of down-stream compounding and processing equipment. 

Polymeric cationic curable formulations containing an d -biphenylthioxanthenium salt initiator 638 have been reported to reduce the residual odor and benzene levels associated with other -phenyl cationic photoinitiator systems <2006W02006/060281 >. The mechanism of photo-acid generation from related rS -aryl thiopyranium salts... 

Next to volatility and water solubility, two additional parameters of odorants greatly affect their performance in application inherent odor strength and odor volume. They are not included in Table 13.4 because they are nearly always desirable. Odor volume may be more or less relevant in different applications, but it is hardly ever undesirable (except in the residual odor of dishwashing detergents) inherent odor strength may be considered to be the basic measure of an odorant s value in terms of intensity. They were not included in Table 13.4 also because few reliable data have been published regarding either of them. Since they depend on the reproducible measurement of human responses, their determination is laborious and fraught with pitfalls. 

Essentially odor-free carrier imparts no residual odor on the goods, even with low-temperature drying. Efficiently builds and levels disperse or cationic dyes on polyester, acts as a compatlbilizer for cationic and anionic dyes, and minimizes cross-stain in blend dyeing. 

The residual odor of tertiary amines is objectionable in many applications, such as bedding, upholstery, and bottle wadding. This odor may be minimized by using volatile catalysts such as N-methyl morpholine, the structure of which is shown as follows ... 

Environmental criteria have been established for many of these, but the utility and applicability of such criteria for indoor environments is controversial for at least four reasons. Eor example, the goals of the threshold limit values often do not include preventing irritation, a primary concern in indoor environments with requirements for close eye work at video display terminals. For most of the pollutant categories, the problem of interactions, commonly termed the multiple contaminants problem , remains inadequately defined. Even for agents that are thought to affect the same receptor, such as aldehydes, alcohols, and ketones, no prediction models are well established. Finally, the definition of representative compounds for measurement is unclear. That is, pollutants must be measurable, but complex mixtures vary in their composition. It is unclear whether the chronic residual odor annoyance from environmental tobacco smoke correlates better with nicotine, particulates, carbon monoxide, or other pollutants. The measure total volatile organic compounds is meanwhile... 

After the paper making process is complete, latexes that are useful as binders for the application of clays or CaCC>3 to paper for printing paper may be prepared using the dimer of AMS. In a typical formulation, styrene, butadiene, Me methacrylate, and acrylonitrile were emulsion polymerized in the presence of AMS dimer to obtain a copolymer latex.473 Surprisingly, the AMS dimer was used in combination with tert-dodecylmercaptan, so there may have been some residual odor. Unsaturated carboxylic acids, such as acrylic acid, or sulfonic acids, such as 2-ethylsulfonyl acrylate, or unsaturated amides, such as acrylamide, are also useful, providing the polarity necessary in these applications.474... 

A very important property of polymers used in printing inks and overprints, especially for plastic substrates, is their ability to release solvents. Some polymers retain a small percent of solvent, thereby causing poor film characteristics or an objectionable residual odor. The propionates have been found to have excellent solvent-release characteristics and are used in laminating inks for plastic because of this property. Figure 7 compares solvent release of CAP-504-0.2 with that of other polymers used in plastic coatings. 

Other sets of circumstances are presented when several impurities are present, each having dissimilar characteristics. Here it is often necessary to include several methods of separation with each method selectively taking out particular impurities e.g., in the manufacture of a pharmaceutical product, some impurities were removed by distillation, others by crystallization, leaving a residual odor to be removed by carbon. 

Now that we have discussed the processes that can be used to create multilayer structures, coating, coextrusion, and lamination, the question arises, which process should be used, and when Liquid adhesive systems usually run faster than extrusion laminating and coating systems. If one is using a solvent-based system, there is the issue of whether or not any residual odors that might affect the product to be packaged remain. Water-based systems do not have solvent odors, but they are not necessarily odor-free. 

Properties Gardner 2 max. color low residual odor dens. 9.0 Ib/gal vise. 80-120 cps... 

Uses Epoxy-acrylic in inks and coatings for flexible pkg. requiring low residual odor and extractables, paper upgrading, coatings on wood, paperboard, chipboard... 

Strips of rapid qualitative paper are dipped in a standard liquid and in the liquid under the test. Their odor is compared to establish if the odor of sample is more or less acceptable than the standard to the purchaser and the manufacturer. In a similar method, papers dipped in a standard and specimens are allowed to dry at room temperature and tested for residual odor at specified time intervals. 

The residual odor of a drycleaning grade of perchloroethylene is determined by comparing treated and untreated samples of bleached cotton fabric. The treated fabric is soaked for 5 min in perchloroethylene and dried for 4 hours at room temperature. Good quality perchloroethylene should leave no odor. 

ISO 2498-74. Methyl ethyl ketone for industrial use - Examination for residual odor. 

ASTM D 4494-95. Standard test method for detecting residual odor of drycleaning grade perchloroethylene. 

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