Malodorants stability

Polysulfides, often referred to as thiokols, are produced at low volumes as specialty materials geared toward a narrow market. The advantages and disadvantages of polysulfides both reside in the disulfide linkage. Thus they possess low-temperature flexibility and very good resistance to ozone, oil, solvent (hydrocarbons as well as polar solvents such as alcohols, ketones, esters, etc.), and weathering. However, polysulfides have poor thermal stability and creep resistance, have low resilence, and are malodorous. 

Most fabric softeners have a pH of about 3.5, which limits to some extent the materials that can be used in the fragrances. For example, acetals carmot be used because they break down and cause malodor problems in addition, there is the likelihood of discoloration from Schiff bases (imines formed from aldehydes and methyl anthrarulate), certain natural extracts (e.g., oakmosses) and a few specialty chemicals. Testing of Iragrance materials in product bases is done under accelerated aging conditions (e.g., 40°C in plastic bottles) to check for odor stability and discoloration. 

Effect on detergent composition must also be considered. Reciprocally, enzymes may cause problems in the product. The perfume stability may be affected (appearance of a malodor) and some ingredients may be degraded. For instance, siufactants of the polyester type such as lauric acid derivatives are superior to polyethers, but they cannot be used in enzymatic detergents, because they are split into inactive substances [50]. 

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