Organotin compounds as PVC

Simpson and Currell [32] used butanol - glacial acetic acid (97 3) as the mobile phase and sprayed the developed plate with catechol violet solution followed by irradiation of the plate for 10 minutes with UV radiation and a respray with catechol violet solution to detect the separated compounds as blue spots. This procedure can be applied to the detection of organotin compounds in PVC using a preliminary extraction of the additives from 5 g polymer with diethyl ether for eight hours. Ether is removed by evaporation and ethanol added to precipitate polymer which is then filtered off. If more accurate quantitative results are required it is necessary to perform an extraction additional to the diethyl ether extraction by using an azeatrope of carbon tetrachloride - methanol (2 1) for a further four hours. 

The organotins have a wide range of uses, which are largely specific for the different organotins. Thus, mono-and disubstituted organotin compounds are not suitable as biocides, and trisubstituted organotin compounds are not suitable as PVC stabilizers. 

Similarly, while the main products used as stabilizers in PVC are mono- and disubstituted compounds, owing to the chemistry involved in their production, trisubstituted organotin compounds will comprise a small fraction of the total amount. This could be significant in assessing the toxicity of the compounds (see below). 

Organotin compounds are important industrial chemicals. One major use is as stabilizers for poly(vinyl chloride) (PVC) plastics. These additives, one example of which is dioctyltinmaleate, inhibit degradation of the polymer by heat, light, and oxygen. In the absence of these tin compounds, PVC yellows and becomes brittle. 

Applications Since the introduction of commercial GC-MIP-AES systems, organometallic analysis can be performed routinely, e.g. for speciation of organotin compounds used as PVC stabilisers [356], The hyphenated GC-AED technique can be used to improve the efficiency of additive analysis. While on the one hand... 

Organotin compounds are used as stabilisers in plastics, especially PVC, and the organotin TBT is used as a treatment against mould in some floor coverings. 

Organotin compounds are ubiquitous in the environment because of their widespread use as thermal and UV stabilisers for polyvinyl chloride (PVC), in agro-... 

Elements Ge, Sn, and Pb form many interesting varieties of organometallic compounds, some of which are important commercial products. For example, EuPb is an anti-knock agent, and organotin compounds are employed as polyvinylchloride (PVC) stabilizers against degradation by light and heat. Some examples and advances are discussed in the present section. 

Organotin compounds are widely used as stabilisers for PVC. They are usually stabilised with R2SnX2 compounds, where R is the alkyl, and X is oxygen, ester, mercaptide, acetyl and other groups. 

The first organotin compound, Et2Snl2, was reported by Frankland in 1849. Interest in organotin chemistry developed steadily over the next decades, but it was not until the discovery of the industrial uses of organotin species (e.g. as PVC stabilizers and as biocidal species), a century or so later, that this area of chemistry expanded rapidly. 

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