Abstract: The present disclosure relates to the production of bis-thiol compounds, preferably DMDH/DMDH oligomer mixtures, and their use in the production of liquid polysulfide polymers

Abstract: Process for the preparation of a polysulfide comprising the step of reacting in the absence of a dihaloalkane a bis(2-dihaloalkyl)formal in the presence of (i) a pre-polymer (I) according to structure (I) X—(R2—O)n—CH2—O—(R1—O)m—CH2—(O—R2)p—X??(I), wherein R1 and R2 can be the same or different and are selected from alkane chains containing 2-10 carbon atoms, X is a halogen atom, and n, m, and p are integers that can be the same or different and have a value in the range 1-6, with either (i) sodium polysulfide or (ii) a combination of sodium hydrosulfide and sulfur.

Abstract: Process for the preparation of a polysulfide comprising the step of reacting in the absence of a dihaloalkane a bis(2-dihaloalkyl)formal in the presence of (i) a pre-polymer (I) according to structure (I) X—(R2—O)n—CH2—O—(R1—O)m—CH2—(O—R2)p—X??(I), wherein R1 and R2 can be the same or different and are selected from alkane chains containing 2-10 carbon atoms, X is a halogen atom, and n, m, and p are integers that can be the same or different and have a value in the range 1-6, with either (i) sodium polysulfide or (ii) a combination of sodium hydrosulfide and sulfur.

Abstract: Process for the preparation of a mercapto-terminated liquid polymer comprising the steps of: a) reacting (para)formaldehyde with a halo-alcohol to form a reaction mixture comprising bis(2-dihaloalkyl)formal and b) reacting the reaction mixture of step a) with either (i) sodium polysulfide or (ii) a combination of sodium hydrosulfide and sulfur, wherein the process is performed in the presence of a branching agent selected from the group consisting of di-aldehydes and their corresponding actetals and hemi-acetals.

Abstract: Pre-polymer according to structure (I) X—(R2—O)n—CH2—O—(R1—O)m—CH2—(O—R2)p—X (I) wherein R1 and R2 can be the same or different and are selected from alkane chains containing 2-10 carbon atoms, X is a halogen atom, and n, m, and p are integers that can be the same of different and have a value in the range 1-6. The use of this pre-polymer in the preparation of a liquid polysulfide polymer allows better control over the sulfur and oxygen content and the polarity of the resulting polymer.

Abstract: Process for the preparation of a mercapto-terminated liquid polymer comprising the steps of: a) reacting (para)formaldehyde with a halo-alcohol to form a reaction mixture comprising bis(2-dihaloalkyl)formal and b) reacting the reaction mixture of step a) with either (i) sodium polysulfide or (ii) a combination of sodium hydrosulfide and sulfur, wherein the process is performed in the presence of a branching agent selected from the group consisting of di-aldehydes and their corresponding actetals and hemi-acetals.

Abstract: Pre-polymer according to structure (I) X—(R2—O)n—CH2(R1—O)m—CH2—(O—R2)p—X (I) wherein R1 and R2 can be the same or different and are selected from alkane chains containing 2-10 carbon atoms, X is a halogen atom, and n, m, and p are integers that can be the same of different and have a value in the range 1-6. The use of this pre-polymer in the preparation of a liquid polysulfide polymer allows better control over the sulfur and oxygen content and the polarity of the resulting polymer.

Abstract: In a slitting apparatus for a web of material such as paper, comprising a circular knife which, in its operation position, co-operates with one of a plurality of counter-blades defined at the periphery of a grooved roller, the rotary axis of the knife in the operative position of the latter is inclined at an acute angle to the roller axis.