Silanols fluids, molecular weight

Elastomers and nonsilanol terminated fluids are produced by base-catalyzed polymerization of low-molecular weight siloxanes. Polydimethylsiloxanes are also produced by ring opening polymerization of D3, D4, and D5. In the presence of MM or MDDM (endcapper), silicones MD M are formed otherwise, silanol terminated polysiloxanes may be obtained. 

This reaction yields the desired silicone fluids with high purities in a quantitative way [4]. By choosing appropriate silanol fluids, amino-fiinctionai fluids with different molecular weights can be obtained [5]. 

In the above reactions, a plurality of acrylate fimctional groups is placed on PDMS, presumably to increase the efficiency of UV cure. However, in order to achieve this goal, relatively inaccessible chlorine substituted PDMS prepared fi om a fairly expensive hydrosilylation reaction between chlorosilanes and vinyl substituted PDMS is used. Also, the formation of triethylamine hydrochloride necessitates the removal of solid from the viscous fluid by filtration. Finally, low molecular weight silanol such as acryloxymethyldimethylsilanol is notoriously unstable (22). Long term storage of the silanol may be troublesome. 

Further studies with the silanol terminated PDMS of various molecular weights confirmed our findings. Silanol fluids with viscosity as high as 50,000 cps ( Mn =... 

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