Process NMR

Table 5

29Si NMR Chemical Shifts - Silicone Materials

Chemical Shift
Region (ppm)Silicone Species
+10 to +4polymer termination sites (SiO(CH3)3) M
-5 to -15polymer termination sites (SiO(CH3)2OH) MOH
-10 to -20Motionally restricted silicone polymer. Cross-lonked and hydrogen bonded (O-Si(CH3)2-O-) as well as D within 5 monomer units of polymer termination
-21D Units - motionally unrestricted silicone (O-Si(CH3)2-O-)n
-75 to -85Q1 (Si(OSi)(OH)3 Silicate Center(M(OH)3
-85 to -94Q2 (Si(OSi)2(OH)2 Silicate Center(D(OH)2
-94 to -104Q3 (Si(OSi)3(OH) Silicate Center(T(OH))
-104 to -120Q4 (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)
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