Comparatively Speaking: Trisiloxane vs. Dimethicone Copolyol

By: Anthony J. O'Lenick Jr., Siltech LLC

Posted: January 19, 2011

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The surface tension measurements shown in Table 1 indicate that the product hydrolyzes after five days at pH 4. In addition, surface tension measurements indicate the product hydrolyzes after seven days at pH 10. The development of haze predicts the instability even earlier. The trisiloxane at pH 4 became hazy the next day, while the pH 10 sample became hazy after three days.

Conclusions

The products tested without pH adjustment were stable at RT for at least eight weeks and there were no observable changes in surface tension for the silicone polyethers at 0.1% in water. The solutions remained clear and the surfactants did not hydrolyze in the water during the 28 days of sitting at RT.

Trisiloxane solutions adjusted to pH 10 were not stable after three days of sitting at RT. The solution became hazy after three days and remained hazy at the end of the experiment.

Trisiloxane solution adjusted to pH 4 with acetic acid was not stable after one day at RT. The solution became hazy over night and the surface tension increased rapidly in the first week of sitting. The solution became clear again and some oily liquid was found on the inside walls of the bottle. It also lost the foaming capability gradually during the first week of sitting.

Dimethicone copolyol at pH 10 and pH 4 was found to be stable at RT after eight weeks, and there were no obvious changes in the surface tensions and foaming properties for these silicone surfactants.