Table 1. Gas-chromatographic retention times of peaks with characteristic mass fragments belonging to poly(oligomethylsiloxanes) and amino-substituted polysilaxanes in dry and wet surface swabs obtained from model polysiloxane coatings.
Silicone sample | Retention time (min) | |||||||||||||
MW | CL | Oil | Swab | 8.05 | 9.54 | 9.68 | 9.77 | 9.99 | 10.29 | 10.98 | 11.55 | 11.65 | 12.03 | 12.48 |
L | L | − | Dry | ▪ | ▪ | ▪ | ▪ | ▪ | ▪ | |||||
L | H | − | ▪ | ▪ | ▪ | ▪ | ▪ | ▪ | ||||||
H | L | − | ▪ | ▪ | ▪ | ▪ | ▪ | ▪ | ||||||
H | H | − | ▪ | ▪ | ▪ | ▪ | ▪ | ▪ | ||||||
L | L | + | ▪ | ▪ | ▪ | ▪ | ▪ | ▪ | ||||||
L | H | + | ▪ | ▪ | ▪ | ▪ | ▪ | ▪ | ||||||
H | L | + | ▪ | ▪ | ▪ | ▪ | ▪ | ▪ | ||||||
H | H | + | ▪ | ▪ | ▪ | ▪ | ▪ | |||||||
L | L | − | Wet | □ | ▪ | ▪ | ▪ | ▪ | ▪ | ▪ | ||||
L | H | − | □ | ▪ | ▪ | ▪ | ▪ | ▪ | ▪ | |||||
H | L | − | □ | ▪ | ▪ | ▪ | ▪ | ▪ | ▪ | |||||
H | H | − | □ | ▪ | ▪ | ▪ | ▪ | ▪ | ▪ | |||||
L | L | + | □ | ▪ | ○ | • | ▴ | ▪ | ▪ | ◊ | ▪ | ▪ | ▪ | |
L | H | + | □ | ▪ | ○ | • | ▴ | ▪ | ▪ | ◊ | ▪ | ▪ | ▪ | |
H | L | + | □ | ▪ | ○ | • | ▴ | ▪ | ▪ | ◊ | ▪ | ▪ | ▪ | |
H | H | + | □ | ▪ | ○ | • | ▴ | ▪ | ▪ | ◊ | ▪ | ▪ | ▪ |
The samples under investigation were characterized by high (H) and low (L) molecular weight (MW), polymerized with the addition of low (L) and high (H) amounts of cross linker (CL), and with (+) or without (−) the addition of silicone oil (Oil). Different organosiloxanes with similar mass-to-charge fragments (73, 147, 221, 281, 355, 429) are denoted by (▪)†. Characteristic mass fragments in different polysilaxanes were □ (351, 379); ○ (87, 115, 351, 379, 437); • (87, 115, 277, 421); ▴ (87, 115, 337, 481); ◊ (87, 115, 439, 583). † As polydimethylsiloxanes of different ring size show almost identical mass fragmentation patterns the exact elucidation of repeat units (n) was not possible.