T-Alkyl peresters of t-hydroperoxides catalysts for polymerization of unsaturated monomers

Novel tertiary alkyl peresters of tertiary hydroperoxides are used as polymerization initiators wherein the peresters are characterized by the tertiary alkyl group of the acid moiety having at least two alkyl groups of two or more carbon atoms and the tertiary alkyl group of the hydroperoxide has at least five carbon atoms. Typical is the polymerization of certain vinyl monomers such as vinyl chloride.

This invention relates to polymerization using organic peroxide initiators. 
More particularly, it relates to certain t-alkyl peresters of 
t-hydroperoxides and their use in the polymerization of monomers such as 
vinyl chloride. 
The above-referenced U.S. Pat. No. 3,624,123, incorporated herein by 
reference, discloses tertiary alkyl peroxyesters of neoacids in which the 
tertiary or alpha carbon atom relative to the carbonyl group of the acid 
has not more than one and preferably no methyl groups substituted thereon. 
With respect to the hydroperoxides which are reacted with these neoacids, 
the only tertiary alkyl hydroperoxide specifically disclosed is tertiary 
butyl hydroperoxide. It has now been discovered that analogous peresters 
formed from higher molecular weight tertiary alkyl hydroperoxides are 
surprisingly more efficient initiators for styrene, vinyl chloride, vinyl 
acetate and ethylene. The peroxyesters of this invention are organic 
peroxides of the formula: 
##STR1## 
wherein R.sub.3, R.sub.4 and R.sub.5 are the same or different alkyl 
groups of from 1 to about 10 carbon atoms provided not more than one of 
R.sub.3, R.sub.4 and R.sub.5 is methyl; and R is selected from t-amyl and 
straight chain alkyl of 2-5 carbon atoms. 
The above-defined peroxyesters are prepared by the same procedures 
described in said U.S. Pat. No. 3,624,123 except that hydroperoxides of 
the formula: 
##STR2## 
wherein R has the above definition are substituted for the hydroperoxides 
utilized in said patent. The present hydroperoxides may be reacted with 
any of the neoacids (conveniently in the form of the neoacid halide) 
defined in said patent and the peroxides of the present invention are 
obtained.

EXAMPLE I 
This example illustrates the superior performance obtained by the use of 
peresters of 1,1,3,3-tetramethyl butyl hydroperoxide. The four peroxides 
shown in Table 1 were prepared in accordance with the procedures described 
in U.S. Pat. No. 3,624,123, particularly Examples I and II thereof. 
Peroxide -3, the neodecanoate perester, is an isomeric mixture formed by 
reacting 1,1,3,3,-tetramethyl butyl hydroperoxide with the acid chloride 
of Enjay Chemical Company's neodecanoic acid which is stated by the 
manufacturer to have an isomer distribution of about 31% by weight alpha 
dimethyl substituted isomers, about 67% by weight of alpha-methyl, 
alpha-higher alkyl isomers and about 2% by weight of alpha dialkyl (higher 
than methyl) substituted isomers. The other peroxides in Table 1, numbers 
1, 2 and 4 are single isomeric forms of the perester indicated and were 
obtained by reacting the hydroperoxide with the corresponding single acid 
chloride isomer. Peroxide numbers 1 and 2 represent the prior art as shown 
in U.S. Pat. No. 3,446,831 and are included for comparison. The peroxides 
obtained were then used in the production of polyvinyl chloride (PVC) in 
accordance with the following procedure. 
Into a 6 1/2 fluid ounce Coke bottle, containing 94.0 g of frozen 
dispersing solution, were added the appropriate amount of peroxide and 
50.0 g of vinyl chloride monomer. The peroxides of Table 1 were added to 
the vinyl chloride monomer to comprise 0.03% by weight or 8.61 .times. 
10.sup.-5 moles thereof. The Coke bottle was capped, the contents almost 
melted, and then the bottle is placed in a rotating constant temperature 
bath for 6 hours at 50.degree..+-.0.5.degree. C. After the bottle was 
cooled, and the excess monomer vented, the PVC was filtered, washed, and 
dried at 40.degree.-50.degree. C. for 12-16 hours. The results are as 
follows: 
TABLE 1 
______________________________________ 
Avg. PVC Avg. PVC 
Peroxide Yield, g. Yield, % 
______________________________________ 
1. 1,1,3,3-tetramethylbutyl- 
perpivalate 10.66 21.3 
2. 1,1,3,3-tetramethylbutyl 
per 2,2-dimethyl valeroate 
27.16 54.3 
3. 1,1,3,3-tetramethylbutyl 
per Neodecanoate 32.12 64.2 
______________________________________ 
EXAMPLE II 
The initiators shown in Tables 2 and 3 were prepared by the procedures of 
U.S. Pat. No. 3,624,123 by reacting a hydroperoxide of the tertiary alkyl 
configuration shown in the peroxyester listed with an isomeric mixture of 
neodecanoyl chloride derived from the Enjay isomeric composition described 
in Example I hereof. The peroxyesters were then used to produce PVC in 
accordance with the following procedure. 
6 1/2 fluid ounce Coke bottles are used for polymerization at 50.degree. C. 
The Coke bottles are prepared by weighing 94.0 g. of suspension solution 
into the bottles, freezing the suspension solution, adding the initiator 
as a 1 ml aliquot in odorless mineral spirits, and placing the stoppered 
bottles in the freezer overnight. The bottles are then filled with 50 g of 
inhibited vinyl chloride monomer (VCM). The monomer is purchased from 
Matheson Gas Products and contains 28-89 ppm phenol as inhibitor. After 
filling the bottles with VCM, they are capped and placed in a 40.degree. C 
water bath until the ice is melted. They are then placed into a constant 
temperature bath at 50.0.degree..+-.0.5.degree. C for the desired 
polymerization times. The bottles rotate at 25 RPM in the constant 
temperature bath. All initiator concentrations are adjusted to a 100% 
purity basis, and all bottles are run in duplicate at each concentration. 
The suspension solution is prepared by dissolving 16.92 Dow Methocel 65 HG 
(50 cps) and 15.00 g Na.sub.3 PO.sub.4.12 H.sub.2 O in 14.10 liters of 
distilled water. The water to VCM ratio is 1.88 to 1 with 0.23 Dow 
Methocel 65 HG and 0.20 g Na.sub.3 PO.sub.4 . 12 H.sub.2 per 100 g VCM. 
Peroxide -1 of Tables 2 and 3 is the tertiary butyl peroxyester previously 
specifically disclosed in U.S. Pat. No. 3,624,123. The improved reaction 
rates and polymer yield of the peroxyesters of this invention are shown in 
Tables 2 and 3 by comparison therewith. 
TABLE 2 
__________________________________________________________________________ 
(50.0 .+-. 0.5.degree. C, 6 Hrs.) 
Moles Wt. PVC, 
Avg. Wt. 
Avg. % 
Initiator % Wt. 
(.times. 10.sup.-4) 
g. PVC, g. 
Conversion 
__________________________________________________________________________ 
t-butyl peroxyneodecanoate 
0.050 
1.023 24.80 24.48 49.0 
24.48 
24.15 
t-Amyl Peroxyneodecanoate 
0.051 
1.023 31.50 31.39 62.8 
31.11 
31.57 
t-Hexyl Peroxyneodecanoate 
0.053 
1.023 32.15 32.13 64.3 
32.11 
t-Heptyl Peroxyneodecanoate 
0.055 
1.023 30.51 30.94 61.9 
31.38 
30.92 
t-Octyl Peroxyneodecanoate 
0.056 
1.023 28.61 28.47 56.9 - 28.33 
28.46 
__________________________________________________________________________ 
TABLE 3 
__________________________________________________________________________ 
(50.0 .+-. 0.5.degree. C) 
Moles % Conversion 
Initiator % Wt. 
(.times. 10.sup.-5) 
Reference 
Time Hrs. 
2 4 6 8 10 12 
__________________________________________________________________________ 
t-butyl peroxy- 
0.045 
9.21 136-32 8.7 2.13 34.6 46.8 56.8 66.6 
neodecanoate 
0.053 
10.84 
149.5 12.9 31.1 54.9 73.9 83.9 86.7 
0.06 
12.28 
136-33, 38 16.0 36.7 65.1 84.4 86.1 87.9 
t-Amyl Peroxy- 
0.02 
3.87 1554-6 6.8 16.4 29.6 40.7 51.2 67.2 
neodecanoate 
0.03 
5.81 1554-6 9.9 27.1 42.8 59.5 76.6 87.6 
0.04 
7.74 1554-5 13.5 34.8 55.8.sup.1) 
77.0 88.2 92.4 
0.05 
9.68 1554-5 17.3 43.2 66.3 87.4.sup.2) 
92.9 93.2 
t-Hexyl Peroxy- 
0.035 
6.42 1575-42 11.6 29.5 45.9 64.0 79.8 86.1.sup.2) 
neodecanoate 
0.045 
8.26 1575-35 9.7.sup.1) 
30.5 48.1 68.3 79.8 87.1 
0.055 
10.10 
1575-32 17.1 43.6 65.7 84.9 88.7 90.3 
t-Heptyl Peroxy- 
0.035 
6.11 1575-42 8.5 25.9.sup.2) 
42.5 58.4 73.1 81.3.sup.2) 
neodecanoate 
0.045 
7.86 1575-38 13.2 34.6.sup.2) 
54.8 72.8 85.2 87.8 
0.055 
9.60 1575-32 13.8 39.2.sup.2) 
60.0 79.6 86.8 88.9 
t-Octyl Peroxy- 
0.045 
7.49 1575-38 11.6.sup.1) 
30.2 48.3 64.3 81.4 86.2 
neodecanoate 
0.055 
9.15 1575-35 11.8 32.4 51.1 69.2.sup.1) 
80.8 85.9 
0.065 
10.82 
1575-45 14.8 38.7 62.6 79.9 85.9 86.7 
__________________________________________________________________________ 
.sup.1) Poor duplication. 
.sup.2) Single bottle value. 
Aside from the selection of the perester having the structure discussed 
above, the practice of the present method in polymerization of styrene, 
vinyl chloride, vinyl acetate, and ethylene is consistent with prior art 
procedures for initiating the polymerization of such monomers. Thus, the 
present peresters are added in amounts generally comparable to those 
previously used and will usually fall within the range of about 0.005% to 
3% by weight of the monomer content and more commonly about 0.01-0.5% by 
weight of the monomer content. For practical purposes the minimum amount 
of the perester is added which will effectively initiate the 
polymerization of the monomer mass. The usual conditions of temperature, 
pressure, solvents, and the like used in the polymerization of these 
monomers may be employed. In addition, it is contemplated that 
co-catalysts may be included to initiate the polymerization. For example, 
diacyl peroxides such as lauroyl peroxide may be used in combination with 
the present peresters as is understood in the art.