Abstract: A process for making crystalline polymers or copolymers of alpha-olefins containing 3 to 8 carbon atoms, such as polypropylene, by polymerization with a catalyst consisting of a combination of titanium chloride and an organic aluminium compound, in the presence of a stereospecificity additive.This stereospecificity additive has the formula:R.sub.1 --O--(C.sub.p H.sub.2p)--S--R.sub.2,where:R.sub.1 and R.sub.2 are alkyl radicals containing 1 to 4 carbon atoms or are linked together to form a divalent --(C.sub.m H.sub.2m)--radical, andp and m are integers each with a value of 1 to 6;this additive may be used in the presence of an activator.

Abstract: A process for separating sulphonic acids from a paraffin sulphonic acid solution containing in addition to the paraffin sulphonic acids, sulphonic acid, water and optionally non-sulphonated paraffins by mixing the solution with a slightly polar alcohol having solubility in water of less than 7 percent to form an aqueous phase and an organic phase, separating the phases, neutralizing the organic phase and recovering the paraffin sulphonic acids from the neutralized organic phase.