Table 529Si NMR Chemical Shifts – Silicone Materials |
|
| Chemical Shift | |
| Region (ppm) | Silicone Species |
| +10 to +4 | polymer termination sites (SiO(CH3)3) M |
| -5 to -15 | polymer termination sites (SiO(CH3)2OH) MOH |
| -10 to -20 | Motionally restricted silicone polymer. Cross-lonked and hydrogen bonded (O-Si(CH3)2-O-) as well as D within 5 monomer units of polymer termination |
| -21 | D Units – motionally unrestricted silicone (O-Si(CH3)2-O-)n |
| -75 to -85 | Q1 (Si(OSi)(OH)3 Silicate Center(M(OH)3 |
| -85 to -94 | Q2 (Si(OSi)2(OH)2 Silicate Center(D(OH)2 |
| -94 to -104 | Q3 (Si(OSi)3(OH) Silicate Center(T(OH)) |
| -104 to -120 | Q4 (Si(OSi)4 Silicate Center(Q) |
| Explanation of Terms in Table 5: | |
| Silicate Content (% of Si atoms present in silicate filler) | |
| Q4 (% of Si atoms present in Q4 structures in silicate – Si(Osi)4) | |
| Qn (% of Si atoms in Qn structures in silicate (Q1, Q2, Q3)) | |
| Q4/Qn Ratio (Allows relative change in silanol (Si-OH) distribution to be observed.) | |
| Percent Polymer (% of silicon atoms in D and MOH polymer units) | |