Catalytic Considerations—Component II
In my December 29, 2010 post, the question was asked…
How can Novinium get the same cable life extension without a soak period? It would seem to me that Novinium puts less fluid into the cable than one would get with a soak period.
In that first post I provided an abbreviated answer. On January 3, 2011 a second post, Catalytic Considerations – Component I, provided the first portion of a more comprehensive answer. We learned from the abbreviated answer that that when Novinium founders conceived of the first generation of treatment fluid over two decades ago we failed to check the relative diffusion rates of the PMDMS monomer (phenylmethyldimethoxysilane) and the condensation catalyst we had chosen to provide long life. In the first component of the comprehensive answer we learned about the unfortunate shortcoming of the first generation catalyst. In this last post I will reveal the secret behind the new generation of catalyst that elegantly solves the problem of premature exudation. The solution, protected by U.S. Patent 7,700,871 and other still pending applications, is a material called DDBSA or dodecylbenzenesulfonic acid. A chemical representation of DDBSA is illustrated nearby. Based upon what we learned in the previous post, and at first glance, DDBSA’s large size would imply a slow catalyst diffusion coefficient and the same problem suffered by the older approach. But looks can be deceiving. I am living proof of that old aphorism.
It is necessary to study DDBSA more carefully. The “H” in the DDBSA molecule (on the top left corner) is a loosely held hydrogen atom or a proton. The DDBSA generously shares this proton with silane and siloxane materials. In the example illustrated, the DDBSA protonates (pronounced pro-toe-nayts) the PMDMS (phenylmethyldimethoxysilane). That is, the hydrogen moves from DDBSA and resides on the PMDMS molecule as shown by the curved arrow. This reaction yields a negatively charged DDBSA cation (pronounced cat-ion) and a protonated PMDMS molecule. The protonated PMDMS molecule is capable of catalyzing its own condensation reaction and that of its neighbors. The molecular weight of the PMDMS increases from 182.3 to 183.3, an inconsequential 0.5% mass increase, and the molecular radius remains virtually unchanged. In other words, the protonated PMDMS diffuses right along with its unprotanted brethren and catalyzes their condensation. While the example provided illustrates the PMDMS molecule included in Cablecure iXL fluid, the same principle applies to the tolylethylmethyldialkoxysilanes (TEMDAS) included in the Cablecure 732 and 733 [Ultrinium™ 732 and 733] fluids. Cablecure 732/733 [Ultrinium] fluids have one other catalytic surprise. Each of these fluids includes a cyanobutylmethyldialkoxysilane (CBMDAS), which is autocatalytic. That is, CBMDAS condenses without the need for any catalyst.
With catalyst and monomer diffusion perfectly matched, the catalytic efficiency for Cablecure iXL, and Cablecure 732 fluids is 98% or better. Plus there is a bonus. The DDBSA cation not only delivers the catalytic proton to the formulation, it is a potent tree retardant itself. The Cablecure iXL and Cablecure 732 formulations includes several of these “two-fors.” That is, a single component that delivers two functions for the price of one. In subsequent posts I will share more two-fors.