Tetramethyl disiloxane

Siloxane-(methyl methacrylate) networks showing high oxygen permeabilities were prepared by gamma-irradiation of tx,(o-methacryloyl terminated tetramethyl-disiloxanes and methyl methacrylate 325). Due to the utilization of very low molecular weight disiloxane modifier, no phase separation was observed in the networks produced. DSC studies showed only one Tg around 120 °C. These materials were evaluated... 

Finally, an alternative in situ preparation of the silyl iodide 1789 from tetramethyl-disiloxane 1788 has been described. The silyl iodide 1789 reduces aromatic aldehydes, such as benzaldehyde 1790 a, or ketones such as acetophenone, 1790b, into the iodides 1791 a,b, andquinones 1792 into the hydroquinones 1793 [33] (Scheme 12.11). 

Sormani PM, McGrath JE (1985) Kinetics and mechanisms of the anionic ring opening polymerization of cyclosiloxanes in the presence of bis(l,3-aminopropyl tetramethyl-disiloxane) In McGrath JE (ed) Ring opening polymerization kinetics mechanisms and synthesis. ACS Symposium Series No 286... 

Thus, the availability of the four-membered metallacycle in the catalytic cycle greatly enhances the rate of disproportionation of tetramethyl-disiloxane. To account for the catalytic activity leading to the oligomeric... 

More recently, Dvornic et al. [64,65] used the hydrosilylation polymerization method between 1,1,3,3-tetramethyl disiloxane and 1,3-divinyl 1,1,3,3-tetramethyl disiloxane and succeeded in obtaining the first hybrid siUcones, called here polycarbosiloxanes, with a high molecular weight (up to 76 000), according to the following reaction ... 

CAS 2627-95-4 EINECS/ELINCS 220-099-6 Synonyms Bis (ethenyidimethylsilyl) ether 1,3-Diethenyl-1,1,3,3-tetramethyldisiloxane Disiloxane, 1,3-diethenyl-1,1,3,3-tetramethyl- Disiloxane, 1,1,3,3-tetramethyl-1,3-divinyl- 1,3-Divinyltetramethyldisiloxane... 

Cyclosiloxanes can, for example, be polymerized to high-molar-mass polysiloxanes with the dipotassium salt of tetramethyl disiloxane diol as initiator. A series of cyclosiloxanes are also present at the polymerization equilibrium ... 

The highest X-ray resist sensitivity has been obtained by using an elegant resist technique referred to as photo-locking [47]. The resist consists of a plasma-degradable acrylic polymer (poly(2,3-dichloropropyl acrylate)) and a volatile silicon-containing acrylate (bis-acryloxybutyl tetramethyl disiloxane, Figure 6.22) which can be readily polymerised by the absorbed radiation. 

Figure 6.22 Bis-acryloxybutyl tetramethyl disiloxane (BABTDS) used for photolocking...

Dimethylisocyanatosilane 502 was prepared from urea and 1,1,3,3-tetramethyl-disiloxane 501 [355]. 

In addition, ADMET has been utilized to polymerize a telechelic oligomer formed from the hydrosilation of 1,4-pentadiene with 1,1,3,3-tetramethyl-disiloxane [107]. ADMET has also been used to produce copolymers with backbone siloxanes and methoxy-substituted silanes [109]. These methoxy-substituted silanes gradually cross-link upon exposure to air, a potentially useful phenomenon (Figure 13.15). Carbosiloxane and oligo(oxyethylene) polymers... 

B. Synthesis of Bis(3-trimethylsiloxypropyl)tetramethyl Disiloxane (BTTD) from Allyloxytrimethylsilane... 

In a dry three-neck roimd bottom flask, 8fr(3-hydroxypropyl)tetramethyl-disiloxane (5g, 2 mmol) was dissolved in dry DMF (25 mL). 2,5-TDI (3.48g, 2mmol) in dry DMF (lOmL) was added dropwise to the solution under nitrogen at room temperature. The reaction mixture was stirred at 80°C for 24 h. The solution was poured into cold methanol to precipitate the polymer. A pale yellow polymer was filtered and washed with methanol yield 90%. 

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