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Evonik Polymer OH 2

Evonik Polymer OH 2 is a polydimethyl siloxane with terminal silanol groups, serving as a fundamental component in the formulation of condensation-curing silicone elastomers. This product is offered in a range of viscosity levels, spanning from 100 to 400,000 mPas. In its physical form, it appears clear and colorless. Chemically, it is characterized as hydroxy-terminated polydimethyl siloxanes.

Functions: Binder & Resin, Reactive Diluent, Rheology Modifier

Knowde Enhanced TDS

Identification & Functionality


Features & Benefits

Applications & Uses


Polymer OH can be cured with usual condensation crosslinkers such as alkoxy silanes, acetoxy silanes, oxime silanes (Crosslinker OX) and enoxy silanes in connection with catalysts (e. g. tin catalysts, Catalyst TD 18). Especially the low-viscosity types can be used as reactive diluents for the viscosity adjustment in a mixture with higher viscosity polymers. The crosslinking reaction occurs in connection with water. In conventional single-component formulations, this water can be introduced through humidity. However, Polymer OH can also be formulated as two component systems. In that case, the required water is added through the second component. Substantially higher curing rates and depths are achieved in this way.


Physical Form
Clear, colorless liquid
Technical Data
ValueUnitsTest Method / Conditions
Viscosity (at 25°C)2000mPa·s-
Refractive Index (nD²⁰)1.4058--
Density (at 20°C)0.98g/cm³-

Regulatory & Compliance

Technical Details & Test Data

Life Cycle Assessment (LCA)

Framework of the LCA

Goal: Calculation of the environmental performance of products manufactured and sold by Business Line Interface & Performance

System Boundary: Cradle-to-Gate

Functional Unit (FU): 1 kg POLYMER OH 2

Methodology: All our Life Cycle Assessments are following the principles of ISO 14040/44 and ISO 14067 standards. The established method of the Dutch Environmental Science Research Center Leiden (CML) with characterization factors from November 2013 was used.

Data Sources: The LCA was created in 2015 by an internal Life Cycle Management team. The LCA is based on primary data from the year 2014 by Evonik for the production process, while secondary data from databases (such as GaBi and ecoinvent), suppliers or literature is utilized for external processes and raw materials. The software GaBi 10 was used for the LCA modeling. The data for energy consumption were updated with values from 2021.

Cut-off rules for the inventory: In general, 1% for single inputs and below 5% for the sum. No environmentally relevant flows were neglected. Some utilities of production processes have been modeled analog to known processes. Transports have been considered but distances have mainly been estimated. The result uncertainty in all categories is about ± 20% as these results base on several assumptions.

Results (Cradle-to-Gate)

Evaluation variables Value Unit per FU
Blue water consumption 63.8 kg
Acidification Potential 0.02 kg SO2 eq.
Global Warming Potential incl. LUC 6.4 kg CO2 eq.
Primary Energy Demand 137.9 MJ

Packaging & Availability

Packaging Type

950 kg IBC PE, 190 kg drum

Storage & Handling

Shelf Life
24 months

Dry, up to 30 °C (86 °F) in sealed containers