Abstract: The present invention provides a modified sulphur composition comprising: a first modified sulphur prepared by admixing molten elemental sulphur with one or more olefinic sulphur modifiers selected from, for example, the group consisting of norbornenes, dicyclopentadiene, cyclopentadiene, oligomers of dicyclopentadiene; and a second modified sulphur prepared by admixing molten elemental sulphur with one or more olefinic sulphur modifiers selected from styrene and derivatives thereof, dicyclopentadiene, cyclopentadiene, dipentene, oligomers of dicyclopentadiene, naphthalene and limonene. The first modified sulphur is different than the second modified sulphur.

Abstract: The invention provides modified sulphur comprising sulphur and a polysulphide-containing organosilane in an amount of in the range of from 0.3 to 25 wt % based on the weight of sulphur, in which modified sulphur the combined amount of sulphur and polysulphide-containing organosilane make up in the range of from 90 to 100 wt % of the obtained modified sulphur and wherein the polysulphide-containing organosilane is of the general molecular formula (1): (X3Si)mH(2n+1?m)Cn-Sa-Cn?H(2n?+1?m?)(SiX?3)m?; wherein a is an integer in the range of from 2 to 8, X and X? each are, independently, a hydrolysable group, n and n? each are, independently, an integer in the range of from 1 to 4, and m and m? each are, independently, an integer in the range of from 1 to (2n+1). The invention further provides a process for preparing such modified sulphur, a sulphur cement product comprising the modified sulphur and a process for preparing such.