Struktosil 45 MAM is a special activated talc, produced by modifying the surface with a methacrylic functional group. There is anchoring on the surface, and all released by-products are removed during the production process. In this way, the material improves its hydrophobic properties.

During compounding, the methacrylic groups of Struktosil 45 MAM provide good wetting and very good dispersion in the matrix polymer. During vulcanization in elastomers or crosslinking of unsaturated polymers, the methacrylic groups of Struktosil 45 MAM react with the polymer in the presence of radicals.

Fields of application

Struktosil 45 MAM is used in elastomers and thermoplastics as well as in paints and coatings, thermosets, reactive resins and adhesives. 
Within elastomers, compounds for gaskets with very good compression set and very low swelling in hot water as well as very good barrier behavior to gases. Due to the modification with a methacrylic functional group, a better integration of the filler platelets into the polymer matrix is possible, which leads to an improvement of the compound properties.


  • Preferably peroxide-cured compounds, e.g. EPDM, HNBR, etc.

Paints and varnishes

  • Anti-corrosion coatings
  • UV-curing varnishes


Struktosil 45 MAM was tested in a peroxide cured EPDM formulation for molded parts, 120 phr filler, in blend with 25 % Struktosil with 75 % ImerFlex T10 and compared to 100 % ImerFlex T10 and amino-functional talc of the competition.


Struktosil 45 MAM in blend with ImerFlex T10  (1 : 3) to 100 % ImerFlex T10 
Peroxide Cured:

  • lower tangent delta at the end of vulcanization
  • strongly increased moduli
  • higher tensile strength
  • strongly reduced compression set
  • slightly increased tear resistance (Graves)
  • improved abrasion resistance
  • better hot-air resistance: lower increase in modulus and hardness, lower decrease in elongation at break
  • better hot water resistance: lower water absorption

Struktosil 45 MAM in 25 % blend with ImerFlex T10 (1 : 3) to 100 % Mistrobond R10C 
Peroxide Cured:

  • lower tangent delta at the end of vulcanization
  • higher moduli
  • slightly higher tensile strength
  • slightly higher tear resistance (Graves)
  • significantly lower compression set
  • improved abrasion resistance
  • better hot air resistance: lower modulus and hardness increase, lower elongation at break decrease
  • better hot water resistance: lower water absorption

Technical poster

Technical report


Product characteristics Unit STRUKTOSIL 45 MAM
Color values L*
Color values b*
Particle size D50
Particle size D97
Volatile matter at 105 °C % 0.2
pH Value 9.5
Bulk density
Spec. Surface area (BET)
Oil absorption
g/100 g
Paper bag

In order to make available to you the most important information about our products at all times, you will find here the Material Specification.


The aspects to observe when working with our products are detailed in our Material Safety Data Sheet, which also can be downloaded.


All information about material characteristics, application fields and benefits can be found in this Technical Data Sheet and is also for download available here.