Symmetrical bis(unsymmetrical tertiary-alkyl and tertiary- aralkyl azo) compounds
AssigneePennwalt Corporation
InventorsRonald Edward Mac Leay, Chester Stephen Sheppard
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Abstract
Novel symmetrical bis(unsymmetrical t-alkyl and t-aralykl azo) compounds of the general formula I: R -- N = N -- R.sub.12 -- N = N -- R' (I) wherein R = R' = (R").sub.3 C--, e.g., 1,2-ethylene bis(4-t-butylazo-4-cyanovalerate); and the use of I for sequential generation of free radicals, e.g. styrene monomer and 1,2-ethylene bis(4-t-butylazo-4-cyanovalerate) are reacted to obtain polystyrene containing attached azo groups which in turn is reacted with methyl methacrylate monomer to obtain a block copolymer of polystyrene and poly(methyl methacrylate).
Claims11
The process for preparing a polymer by free radical initiation, the improvement which comprises polymerizing at least one monomer containing ethylenic unsaturation in the presence of a bis-azo compound having the formula:
- R--N=N--R.sub.12 --N=N--R" (I)
- wherein
- R equals R' equals (R").sub.3 C;
- (r").sub.3 c is C.sub.4 -C.sub.20 t-alkyl, cycloalkyl, alkylcycloalkyl, arylcycloalkyl or aralkyl wherein R" is C.sub.1 -C.sub.8 alkyl, C.sub.7 -C.sub.12 aralkyl or C.sub.6 -C.sub.14 aryl, not more than one R' being aromatic, and two or three of said R"s can join with the tertiary carbon atom to form a cyclo-, bicyclo- or tricyclo-hydrocarbon radical of 3-12 carbons;
- R.sub.12 is ##EQU25## R.sub.1 and R.sub.2 are C.sub.1 -C.sub.8 alkyl, C.sub.3 -C.sub.12 cyclo-, bicyclo- or tricycloalkyl, C.sub.7 -C.sub.12 aralkyl, or 5-6 membered heterocyclic wherein the hetero atom is O or N, R.sub.1 and R.sub.2 taken together can form a C.sub.3 -C.sub.11 alkylene diradical, one or more of each of the R.sub.1 s and R.sub.2 s can be substituted with lower alkoxy, hydroxy, carboxy, lower alkoxycarbonyl, lower alkylcarbonyloxy, halo, cyano, dimethylamido or lower alkylsulfonato radicals, and R.sub.1 can also be C.sub.6 -C.sub.14 aryl;
- Y" is --NHNH--, --S--, --O--, --SS--, ##EQU26## or --X"R.sub.13 X"--;
- Z is --CN, --Cl, --Br, --X"R.sub.5, --N.sub.3, --SCN, --NCS, --OCN, --OOR, --OOH, --OH, --R.sub.5, --NO.sub.2, --NO.sub.3, --C.tbd.CR.sub.10, --C(=O)NH.sub.2, --C(=O)OR.sub.6, --C(=NH)NH.sub.2, --C(=NH)OR.sub.6, --OC(=O)H, --X"C(=X")X"R.sub.5, --X"C(=X")R.sub.5, --OOC(=O)R.sub.5, ##EQU27## ##SPC24##
- or ##EQU28## R'.sub.13 is a C.sub.2 -C.sub.20 symmetrical diradical selected from alkyl, alkylaralkyl or alkylcycloalkylalkyl groups optionally containing two or more non-adjacent oxygen, sulfur or nitrogen atoms in the backbone structure, cycloalkyl or, when R.sub.1 is not phenyl or substituted phenyl, from C.sub.6 -C.sub.12 hydrocarbon aromatic;
- R.sub.13 is a symmetrical C.sub.5 -C.sub.15 alkyl-cycloalkyl, C.sub.2 -C.sub.10 alkylene, C.sub.3 -C.sub.12 cycloalkylene, C.sub.6 -C.sub.12 hydrocarbon aryl or C.sub.8 -C.sub.15 alkyl-aryl diradical;
- X" is oxygen or sulfur;
- R.sub.5 is C.sub.1 -C.sub.10 alkyl or cycloalkyl or C.sub.6 -C.sub.12 hydrocarbon aromatic;
- R.sub.6 is lower alkyl;
- and
- R.sub.10 is hydrogen, C.sub.1 -C.sub.10 alkyl or cycloalkyl or C.sub.6 -C.sub.12 hydrocarbon aryl.
Dependencies are inferred from the claim text.