Modification

Effect of pre-crosslinking

• reduction of the elastic resilience (snappiness) of the raw rubber and uncured compound
• reduction of the die swell
• improvement in calendering behavior
• improvement of the surface smoothness of injection-molded articles
• improvement of the dimensional stability, e.g. of uncured profiles

Effect of sulfur modification

• facilitates mastication of the rubber, permitting the production of soft compounds with good building tack
• only MgO/ZnO required for vulcanization
• better tear resistance than standard grades
• better adhesion to fabrics than standard grades
• lower storage stability of raw polymers
• lower aging resistance of vulcanizates

Effect of XD (xanthogendisulfide) modification

• lower elasticity (less “nerve”) means easier processing (by calendering or extrusion)
• better mechanical properties than M-modified grades in the same formulation
• higher filler loadings possible