Evaporation or sublimation of volatile organic liquids and solids is suppressed by adding to the organic material from 0.005 to 10% by weight of a compound defined as follows. The additive compound has a molecular configuration comprising at least one "head" and one "tail," the "head" comprising a ring of 4 to 8 atoms which are carbon with or without oxygen, nitrogen or sulphur, each ring having substantially only one "tail" comprising aliphatic radicals containing 6-30 carbon atoms and having at most 2 double bonds and being free to rotate with respect to the "head," and the "head" comprising at least one of the polar groups -OR, <FORM:1023213/C4-C5/1> , <FORM:1023213/C4-C5/2> , -N-N-R, -C-, -NO2, sulphate, sulphonate, phosphate, phosphonate, mercaptan and thioacid, in which R is hydrogen or a saturated or unsaturated C1-C5 hydrocarbon radical. Suitable additives are, for example, (a) sugar derivatives such as alkylurea glucosides, pentadecylurea-N-glucosides, monopyranose esters and ethers, esters and ethers of mono- and di-saccharides, fatty acid esters of sorbitol dehydration products; ascorbyl and hydrogenated ascorbyl esters, methylglycoside fatty acid esters, and 5-amino ribofuranose esters; (b) compounds containing rings having 4-8 atoms including one heterocyclic atom, e.g. substituted lactones, tetrahydrofurans and pyridyl glycol ethers and esters; (c) compounds containing rings having 4-8 atoms including two heterocyclic atoms, e.g. imidazoline guanylamines, oxazolines, imidazolines, thiazolidines, oxazolidines, hydantoins, pyrazolidines, pyrazolines and morpholines; (d) compounds containing rings having 4-8 atoms including 3 or more heterocyclic atoms, e.g. triazoles and (e) copolymers of hydrophobic monomers such as stearyl methacrylate with monomers such as vinyl sorbitan, vinyl glucose and vinyl imidazoline. In all cases the substituents include at least one polar group as defined above and an aliphatic radical containing 6-30 carbons. Among the compounds which may be stabilized against volatization are alkanes, e.g. heptanes, cycloalkanes, e.g. cyclohexane and aromatic hydrocarbons, e.g. benzene, toluene, xylene, styrene and naphthalene and gasolines. The additives may also be used to prevent volatilization of dry-cleaning fluids. For example, (a) a mixture of benzene with 5% of sorbitan monostearate is used to dry-clean garments and also to degrease oil-coated metal, and (b) a mixture of trichlorethylene, carbon tetrachloride, ethylene dichloride, or dichlorethylene with 1% of dodecylurea-N1-glucoside is used as a dry-cleaning solvent. It is also stated that paintbrush cleaners and paint and varnish strippers may be stabilized against volatilization by use of the additives.ALSO:An unsaturated polyester is copolymerized with an ethylenically unsaturated monomer in the presence of 0.005 to 10% by weight of a compound whose molecular configuration comprises at least one head and at least one tail, said head comprising a ring of four to eight atoms, said atoms which form the ring within the head being oxygen, carbon, nitrogen or sulphur, each ring within said head having substantially only one tail portion, said tail consisting of aliphatic hydrocarbon radicals containing from 6 to 30 carbon atoms and having at most two unsaturated bonds, said head and tail being joined so that said tail is free to rotate with respect to said head, said head comprising at least one polar group selected from -OR, <FORM:1023213/C3/1> -N-N-R-, -O-, NO2, sulphate, sulphonate phosphate, phosphonate, mercaptan and thioacid, where R is hydrogen or a saturated or unsaturated hydrocarbon radical containing 1 to 5 carbon atoms. Examples of such compounds are sugar derivatives, various heterocyclic compounds having one, two or three heterocyclic atoms, and various miscellaneous compounds, e.g. copolymers of hydrophobic monomers such as stearyl methacrylate with monomers such as vinyl sorbitan, glucose or imidazoline. Lists of suitable compounds are given. In the examples, a "Vibrin" (Registered Trade Mark) polyester resin containing styrene is mixed with chopped glass fibre and sorbitan monostearate and polymerized using a promoter and benzoyl peroxide.ALSO:Evaporation or sublimation of volatile organic liquids and solids is suppressed by adding to the organic material from 0.005 to 10% by weight of a compound defined as follows. The additive compound has a molecular configuration comprising at least one "head" and one "tail," the "head" comprising a ring of 4 to 8 atoms which are carbon with or without oxygen, nitrogen or sulphur, each ring having substantially only one "tail" comprising aliphatic radicals containing 6-30 carbon atoms and having at most 2 double bonds and being free to rotate with respect to the "head," and the "head" comprising at least one of the polar groups <FORM:1023213/C2/1> -NO2, sulphate, sulphonate, phosphate, phosphonate, mercaptan and thioacid, in which R is hydrogen or a saturated or unsaturated C1-C5 hydrocarbon radical. Suitable additives are, for example, (a) sugar derivatives such as alkylurea glucosides, pentadecylurea-N-glucosides, monopyranose esters and ethers, esters and ethers of mono- and di-saccharides, fatty acid esters of sorbitol dehydration products; ascorbyl and hydrogenated ascorbyl esters, methyl glycoside fatty acid esters, and 5-aminoribofuranose esters; (b) compounds containing rings having 4-8 atoms including one heterocyclic atom, e.g. substituted lactones, tetrahydrofurans and pyridyl glycol ethers and esters; (c) compounds containing rings having 4-8 atoms including two heterocyclic atoms, e.g. imidazoline guanylamines, oxazolines, imidazolines, thiazolidines, oxazolidines, hydantoins, pyrazolidines, pyrazolines and morpholines; (d) compounds containing rings having 4-8 atoms including 3 or more heterocyclic atoms, e.g. triazoles and (e) copolymers of hydrophobic monomers such as stearyl methacrylate with monomers such as vinyl sorbitan, vinyl glucose and vinyl imidazoline. In all cases the substituents include at least one polar group as defined above and an aliphatic radical containing 6-30 carbons. Organic compounds which may be stabilized against volatilization are, for example, alcohols, ether, acetone and methyl ethyl ketone, p-dichlorbenzene, trichlorethylenes, alkyl chloride, ethyl chloride, acrolein, diethylamine, trimethylamine, acetonitrile, dioxane, epichlorhydrin, ethyl acetate, furan, methyl formate, propylene oxide and vinyl acetate.ALSO:Evaporation or sublimation of volatile organic liquids and solids is suppressed by adding to the organic material from 0,005-10% by weight of a compound defined as follows. The additive compound has a molecular configuration comprising at least one "head" and one "tail", the "head" comprising a ring of 4-8 atoms which are carbon with or without oxygen, nitrogen or sulphur, each ring having substantially only one "tail" comprising aliphatic radicals containing 6-30 carbon atoms and having at most 2 double bonds and being free to rotate with respect to the "head", and the "head" comprising at least one of the polar groups -OR, <FORM:1023213/B1-B2/1> , <FORM:1023213/B1-B2/2> , -N = N-R, -O-, -NO2, sulphate, sulphonate, phosphate, phosphonate, mercaptan and thioacid, in which R is hydrogen or a saturated or unsaturated C1-C5 hydrocarbon radical. The additive may be used to separate two volatile liquids by distillation, the more volatile liquid evaporating and the volatilization of the other being inhibited. In an example, 1% of sucrose dipalmitate is added to a 50:50 mixture of benzene and methanol which is left exposed to the atmosphere and after some time the remaining solution is found to contain 90% benzene and 10% methanol. A similar result is found with a benzene/ethanol mixture (Examples 125-126).ALSO:Evaporation or sublimation of volatile organic liquids and solids is suppressed by adding to the organic material from .005 to 10% by weight of a compound defined as follows. The additive compound has a molecular configuration comprising at least one "head" and one "tail", the "head" comprising a ring of 4 to 8 atoms which are carbon with or without oxygen, nitrogen or sulphur, each ring having substantially only one "tail" comprising aliphatic radicals containing 6-30 carbon atoms and having at most 2 double bonds and being free to rotate with respect to the "head" and the "head" comprising at least one of the polar groups <FORM:1023213/A5-A6/1> , sulphate, sulphonate, phosphate, phosphonate, mercaptan and thioacid, in which R is hydrogen or a saturated or unsaturated C1-C5 hydrocarbon radical. Suitable additives are, for example, (a) sugar derivatives such as alkylurea glucosides, pentadecylurea -N-glucosides, monopyranose esters and ethers, esters and ethers of mono-and di-saccharides, fatty acid esters of sorbitol dehydration products; ascorbyl and hydrogenated ascorbyl esters, methylglycoside fatty acid esters, and 5-amino ribofuranose esters; (b) compounds containing rings having 4-8 atoms including one heterocyclic atom e.g. substituted lactones, tetrahydrofurans and pyridyl glycol ethers and esters; (c) compounds containing rings having 4-8 atoms including two heterocyclic atoms, e.g. imidazoline guanylamines, oxazolines, imidazolines, thiazolidines, oxazolidines, hydantoins, pyrazolidines, pyrazolines and morpholines; (d) compounds containing rings having 4-8 atoms including 3 or more heterocyclic atoms e.g. triazoles and (e) copolymers of hydrophobic monomers such as stearyl methacrylate with monomers such as vinyl sorbitan, vinyl glucose and vinyl imidazoline. In all cases the substituents include at least one polar group as defined above and an aliphatic radical containing 6-30 carbons. Among the materials which may be stabilised against volatilisation by use of the above additives are, for example, moth