TY - JOUR
T1 - Microwave driven trimethylsilylation of phenol-formaldehyde resins
T2 - Extent of reactions determined by 13C and 29Si n.m.r.
AU - Monsef-Mirzai, Parisa
AU - Manak, Harminder
AU - McWhinnie, William R.
AU - Snape, Colin E.
AU - Sirkecioglu, Okin
AU - Andresen, John
PY - 1998/4
Y1 - 1998/4
N2 - A phenol-formaldehyde (PF) resite resin and phenol:2,6-di-t-butylphenol-formaldehyde (DTBPF) co-resite were reacted under conditions of microwave heating with N-(trimethylsilyl)imidazole (TMSI). Low degrees of reaction were observed for the PF resin (19%) and for the DTBPF co-resite (0.3-0.4%) as examples of macromolecular systems with very limited porosity. 13C SPE MAS n.m.r. was an effective method to determine the degree of silylation and 13C CP MAS n.m.r. gave very similar results. When a different reagent mix (1:1:1 N,O-bis(trimethylsilyl)acetamide:N(trimethylsilyl)imidazole: trimethylchlorosilane) was used both 13C and 29Si SPE n.m.r. were in agreement that 100% silylation of the OH groups had been achieved for the PF resin. Thus, with proper choice of conditions and reagents, microwave-driven silylation is a very effective method of OH analysis even for systems of significantly more limited porosity compared with coals.
AB - A phenol-formaldehyde (PF) resite resin and phenol:2,6-di-t-butylphenol-formaldehyde (DTBPF) co-resite were reacted under conditions of microwave heating with N-(trimethylsilyl)imidazole (TMSI). Low degrees of reaction were observed for the PF resin (19%) and for the DTBPF co-resite (0.3-0.4%) as examples of macromolecular systems with very limited porosity. 13C SPE MAS n.m.r. was an effective method to determine the degree of silylation and 13C CP MAS n.m.r. gave very similar results. When a different reagent mix (1:1:1 N,O-bis(trimethylsilyl)acetamide:N(trimethylsilyl)imidazole: trimethylchlorosilane) was used both 13C and 29Si SPE n.m.r. were in agreement that 100% silylation of the OH groups had been achieved for the PF resin. Thus, with proper choice of conditions and reagents, microwave-driven silylation is a very effective method of OH analysis even for systems of significantly more limited porosity compared with coals.
KW - MAS n.m.r.
KW - Microwave heating
KW - Phenol-formaldehyde resites
KW - Silylation
UR - http://www.scopus.com/inward/record.url?scp=0032050247&partnerID=8YFLogxK
U2 - 10.1016/S0016-2361(98)80026-4
DO - 10.1016/S0016-2361(98)80026-4
M3 - Article
AN - SCOPUS:0032050247
SN - 0016-2361
VL - 77
SP - 369
EP - 374
JO - Fuel
JF - Fuel
IS - 5
ER -