Organic peroxides and their use in the preparation of epoxide groups-containing (co)polymers

Novel organic peroxides of the general formula ##STR1## wherein p=0 or 1 and n=1, 2, 3 or 4 are described. These peroxides are excellently suitable for use in the preparation of epoxide groups-containing (co)polymers. Also described are shaped objects obtained by using (co)polymers thus modified.

The invention relates to novel organic peroxides, to a process of preparing 
epoxide groups-containing (co)polymers employing these peroxides and to 
shaped objects. 
It is generally known that the introduction of epoxide groups into the 
appropriate (co)polymers may lead to improved physical and chemical 
properties of the (co)polymers. According to Rubber World 191(6) pp. 15-20 
(1985) and Rubber Developments, Vol. 38 No. 2, pp. 48-50 (1985), for 
instance, the introduction of epoxide groups into natural rubber leads to 
advantages such as an increased glass transition temperature, increased 
oil resistance, reduced gas permeability, improved resilience, increased 
tensile strength, and improved adhesion to other materials, such as silica 
fillers, glass fibres and other polymers, more particularly PVC, which is 
of importance to the preparation of polymeric blends. Further, the 
polymers thus modified permit carrying out chemical reactions that are 
typical of epoxy groups. As examples thereof may be mentioned: i) 
cross-linking the polymer with polyfunctional compounds containing active 
hydrogen atoms, such as polyamines and dibasic acids, which is described 
in Chemical Reactions of Polymers, E. M. Fettes (ed.), Interscience 
Publications, New York (1964), Chapter II, part E, pp. 152 et. seq., ii) 
covalently bonding to the polymer of antioxidants having amino groups in 
the molecule, which is described in Journal of Polymer Science, Polymer 
Letters Edition, Vol. 22, 327-334 (1984) and iii) reacting with 
fluorine-containing compounds, such as trifluoroacetic acid, resulting in 
a polymer with improved lubricity and ozon resistance, which is described 
in WO 85/03477. 
Generally, epoxide groups are introduced into (co)polymers by so-called 
epoxidation reactions, in which an unsaturated (co)polymer in the form of 
a latex or dissolved in an organic solvent is brought into reaction with a 
double bond epoxidizing reagent, such as a lower aliphatic peroxy 
carboxylic acid. To this method, however, there are several disadvantages. 
First of all, the requirement that the (co)polymer should be unsaturated 
implies that only a very limited number of (co)polymers can be provided 
with epoxide groups. For instance, the entire group of saturated 
(co)polymers is excluded from being functionalized by that route. In the 
second place, the use of solvents implies that the epoxidation reaction 
must be followed by a purification step. In addition to the drawbacks to 
such a step from the point of view of processing technique there are the 
obvious disadvantages to the use of solvents from the point of view of 
energy consumption and environmental pollution. In the third place, the 
epoxidation reaction is always attended with side reactions, such as the 
formation of hydroxyl groups, acyloxy groups, ether groups, keto groups 
and aldehyde groups, which detracts from the envisaged object of 
introducing epoxide groups. 
Finally, it should be mentioned that it is well-known to prepare epoxide 
groups-containing (co)polymers by copolymerizations and graft 
polymerizations with monomers containing a glycidyl group (Cf. Journal of 
Polymer Science, Vol. 61, pp. 185-194 (1962), Makromol. Chem., Rapid 
Commun. 7, pp. 143-148 (1986) and Die Angewandte Makromolekulare Chemie 
48, pp. 135-143 (1975)). The inevitable attendant formation, however, of 
undesirable side products, such as the formation of homopolymers of the 
glycidyl group-containing monomer, is considered a drawback in actual 
practice. Moreover, these methods permit preparation of only a limited 
group of modified (co)polymers. 
The invention has for its object to eliminate the above drawbacks to the 
well-known methods of introducing epoxide groups into (co)polymers and to 
that end it provides novel organic peroxides. The peroxide according to 
the invention corresponds to the general formula 
##STR2## 
wherein p=0 or 1; 
n=1, 2, 3 or 4; 
R.sup.1 and R.sup.2 may be the same or different and represent alkyl groups 
containing 1-4 carbon atoms or together represent a pentamethylene bridge; 
R.sup.3, R.sup.4 and R.sup.5 may be the same or different and represent 
hydrogen atoms or alkyl groups containing 1-4 carbon atoms; 
when p=0 and n=1, 
R=a t-alkyl group substituted or not with a hydroxyl group and containing 
4-18, preferably 4-12 carbon atoms, p-menth-8-yl, a t-alkenyl group 
containing 5-18, preferably 5-12 carbon atoms, 1-vinylcyclohexyl or a 
group of the general formula 
##STR3## 
wherein m=0, 1 or 2 and R.sup.6 represents an isopropenyl group or a 
2-hydroxyisopropyl group; 
when p=0 and n=2, 
R=an alkylene group with 8-12 carbon atoms which at both ends has a 
tertiary structure, an alkynylene group with 8-12 carbon atoms which at 
both ends has a tertiary structure, a group of the general formula 
##STR4## 
wherein x=0 or 1 and R.sup.6 has the above-indicated meaning or a group 
of the general formula 
##STR5## 
wherein R.sup.7 and R.sup.8 may be the same or different and represent 
alkyl groups substituted or not with an alkoxy group or an alkoxycarbonyl 
group and containing 1-10 carbon atoms or together represent an alkylene 
bridge substituted or not with one or more methyl groups and containing 
4-11 carbon atoms; 
when p=0 and n=3, 
R=1,2,4-triisopropylbenzene-.alpha.,.alpha.',.alpha."-triyl or 
1,3,5-triisopropylbenzene-.alpha.,.alpha.',.alpha."-triyl; 
when p=0 and n=4, 
R=2,2,5,5-hexanetetrayl; 
when p=1 and n=1, 
R=an alkyl group substituted or not with a chlorine atom, an alkoxy group, 
a phenyl group or a phenoxy group and containing 1-18, preferably 3-8 
carbon atoms, an alkenyl group containing 3-18, preferably 3-8 carbon 
atoms, a cyclohexyl group substituted or not with one or more alkyl groups 
containing 1-4 carbon atoms or cyclododecyl; 
when p=1 and n=2, 
R=an alkylene group containing 2-12, preferably 2-8 carbon atoms, 
##STR6## 
wherein y=1-5; when p=1 and n=3, 
R=a group of the general formula R.sup.9 C(CH.sub.2 --).sub.3 wherein 
R.sup.9 represents an alkyl group having 1-5 carbon atoms. 
The alkyl groups, alkenyl groups and alkylene groups may be linear or 
branched, unless otherwise indicated. In view of sterical requirements it 
should be noted that when there is an aromatic ring in the molecule (see 
above with p=0/n=1 and p=0/n=2), the ring substituents must in the case of 
disubstitution not be in a position ortho relative to each other and in 
the case of trisubstitution not be in three adjacent positions. 
It should be added that Bull. Soc. Chim. France No. 2, 198-202 (1985) makes 
mention of t-butyl allyl peroxide being capable of 2,3-epoxypropanating 
organic solvents with labile hydrogen atoms. As solvents are mentioned 
cyclohexane, tetrahydrofuran, propionic acid, propionic anhydride, methyl 
propionate, acetonitrile and chloroform. The article also mentions the 
need for the presence of an auxiliary initiator having a decomposition 
temperature lower than that of the t-butyl allyl peroxide. But this 
article does not refer to the present invention. Moreover, the peroxide 
described in it is rather difficult to prepare. 
The Peroxides 
The peroxides according to the invention correspond to the above-described 
formula (I) and are selected from the classes of the dialkyl peroxides and 
diperoxy ketals (p=0) and peroxycarbonates (p=1). They may be prepared in 
the usual manner. Use is generally made then of a t-alkenyl hydroperoxide 
of the general formula 
##STR7## 
wherein R.sup.1 -R.sup.5 have the above-indicated meaning. The t-alkenyl 
hydroperoxides in their turn also may be prepared in the usual manner, use 
being made of a t-alkenyl alcohol and hydrogen peroxide in the presence of 
a strongly acid catalyst such as sulphuric acid. As examples of suitable 
t-alkenyl hydroperoxides may be mentioned: 
2-methyl-3-buten-2-yl hydroperoxide, 
3-methyl-1-penten-3-yl hydroperoxide, 
3,4-dimethyl-1-penten-3-yl hydroperoxide, 
3-ethyl-1-penten-3-yl hydroperoxide, 
3-isopropyl-4-methyl-1-penten-3-yl hydroperoxide, 
3-methyl-1-hexen-3-yl hydroperoxide, 
3-n-propyl-1-hexen-3-yl hydroperoxide, 
1-vinylcyclohexyl hydroperoxide, 
2-methyl-3-penten-2-yl hydroperoxide and 
2,3,4-trimethyl-3-penten-2-yl hydroperoxide. 
As the starting alcohol is readily available, it is preferred that use 
should be made of 2-methyl-3-buten-2-yl hydroperoxide (R.sup.1 and R.sup.2 
representing methyl groups and R.sup.3, R.sup.4 and R.sup.5 hydrogen 
atoms). 
In the preparation of a number of the present dialkyl peroxides a t-alkenyl 
hydroperoxide (II) can be reacted in a usual way with an alcohol in an 
acid medium. As examples of suitable alcohols may be mentioned: 
.alpha.-hydroxyisopropylbenzene, 
1,3-di(.alpha.-hydroxyisopropyl)benzene, 
1,4-di(.alpha.-hydroxyisopropyl)benzene, 
1,3,5-tri(.alpha.-hydroxyisopropyl)benzene, 
1-(.alpha.-hydroxyisopropyl)-3-isopropenylbenzene, 
1-(.alpha.-hydroxyisopropyl)-4-isopropenylbenzene, 
1-(.alpha.-hydroxyisopropyl)-3,5-diisopropenylbenzene, 
1,3-di(.alpha.-hydroxyisopropyl)-5-isopropenylbenzene, 
2-methyl-3-buten-2-ol, 
3-methyl-1-penten-3-ol, 
3,4-dimethyl-1-penten-3-ol, 
3-ethyl-1-penten-3-ol, 
3-isopropyl-4-methyl-1-penten-3-ol, 
3-methyl-1-hexen-3-ol, 
3-n-propyl-1-hexen-3-ol, 
1-vinylcyclohexanol, 
2-methyl-3-penten-2-ol, 
2,3,4-trimethyl-3-penten-2-ol and 
p-menthan-8-ol. 
Some dialkyl peroxides according to the invention, however, cannot be 
properly prepared in this manner. In those cases it is preferred that use 
should be made of a t-alkenyl alcohol of the general formula 
##STR8## 
wherein R.sup.1 -R.sup.5 have the above-indicated meaning, which t-alkenyl 
alcohol is reacted with a hydroperoxide in an acid medium. As examples of 
suitable hydroperoxides may be mentioned: 
t-butyl hydroperoxide, 
t-amyl hydroperoxide, 
2,4,4-trimethylpentyl-2-hydroperoxide, 
2,5-dimethyl-2,5-dihydroperoxyhexane and 
2,5-dimethyl-2,5-dihydroperoxyhexyne-3. 
Typical examples of dialkyl peroxides according to the invention are: 
2-(t-amylperoxy)-2-methyl-3-butene, 
1-[.alpha.-(2-methyl-3-buten-2-ylperoxy)isopropyl]-3-isopropenylbenzene, 
1-[.alpha.-(2-methyl-3-buten-2-ylperoxy)isopropyl]-4-(.alpha.-hydroxyisopro 
pyl)benzene, 
1-[.alpha.-(2-methyl-3-buten-2-ylperoxy)isopropyl]-3,5-diisopropenylbenzene 
1-[.alpha.-(2-methyl-3-buten-2-ylperoxy)isopropyl]-3,5-di(.alpha.-hydroxyis 
opropyl)benzene, 
2,5-di(2-methyl-3-buten-2-ylperoxy)-2,5-dimethylhexane, 
2,5-di(2-methyl-3-buten-2-ylperoxy)-2,5-dimethylhexyne-3, 
1,3-di[.alpha.-(2-methyl-3-buten-2-ylperoxy)isopropyl]benzene, 
1,4-di[.alpha.-(2-methyl-3-buten-2-ylperoxy)isopropyl]benzene, 
1,3-di[.alpha.-(2-methyl-3-buten-2-ylperoxy)isopropyl]-5-isopropenylbenzene 
1,3-di[.alpha.-(2-methyl-3-buten-2-ylperoxy)isopropyl]-5-(.alpha.-hydroxyis 
opropyl)benzene, 
1,3,5-tri[.alpha.-(2-methyl-3-buten-2-ylperoxy)isopropyl]benzene, 
2-(2-methyl-3-buten-2-ylperoxy)-2,4,4-trimethylpentane, 
2-(2-methyl-3-buten-2-ylperoxy)-2-methylpentane, 
2-(2-methyl-3-buten-2-ylperoxy)-4-hydroxy-2-methylpentane and 
8-(2-methyl-3-buten-2-ylperoxy)-p-menthane. 
In the preparation of the present diperoxy ketals a t-alkenyl hydroperoxide 
(II) can be reacted in a usual way with a ketone in an acid medium. As 
examples of suitable ketones may be mentioned: acetone, methoxyacetone, 
methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, 
n-butyl-4-ketovalerate, 2,5-hexanedione, cyclohexanone, 
3,3,5-trimethylcyclohexanone, cyclopentanone and cyclododecanone. 
Typical examples of diperoxy ketals according to the invention are: 
2,2-di(2-methyl-3-buten-2-ylperoxy)propane, 
2,2-di(2-methyl-3-buten-2-ylperoxy)-1-methoxypropane, 
2,2-di(2-methyl-3-buten-2-ylperoxy)butane, 
1,1-di(2-methyl-3-buten-2-ylperoxy)-3,3,5-trimethylcyclohexane, 
1,1-di(2-methyl-3-buten-2-ylperoxy)cyclopentane, 
1,1-di(2-methyl-3-buten-2-ylperoxy)cyclododecane, 
2,2-di(2-methyl-3-buten-2-ylperoxy)-4-methylpentane, 
2,2,5,5-tetra(2-methyl-3-buten-2-ylperoxy)hexane and 
4,4-di(2-methyl-3-buten-2-ylperoxy)-n-butylvalerate. 
In the preparation of the present peroxycarbonates a t-alkenyl 
hydroperoxide (II) can be reacted with a chloroformate in the usual way 
under alkaline conditions. As is known, chloroformates can be prepared 
from alcohols and phosgene. As examples of suitable alcohols may be 
mentioned methanol, n-propanol, sec.butanol, isobutanol, n-tetradecanol, 
n-hexadecanol, 2-chloroethanol, methallylalcohol, 3-methyl-2-buten-1-ol, 
3-methyl-3-buten-1-ol, 2-phenylethanol, 2-phenoxyethanol, 
3,5,5-trimethylhexanol, ethylene glycol, diethylene glycol, triethylene 
glycol, tetraethylene glycol, 1,2-propanediol, 1,3-propanediol, 
1,4-butanediol, 1,5-pentanediol, 2,5-hexanediol, 1,8-octanediol, 
1,10-decanediol, 1,12-dodecanediol, 2,2-dimethyl-1,3-propanediol, 
1,4-di(hydroxymethyl)cyclohexane and 1,1,1-trimethylolpropane. 
Typical examples of peroxycarbonates according to the invention include: 
O-ethyl O,O-(2-methyl-3-buten-2-yl) monoperoxycarbonate, 
O-(n-butyl) O,O-(2-methyl-3-buten-2-yl) monoperoxycarbonate, 
O-(n-hexyl) O,O-(2-methyl-3-buten-2-yl) monoperoxycarbonate, 
O-(n-decyl) O,O-(2-methyl-3-buten-2-yl) monoperoxycarbonate, 
O-(n-dodecyl) O,O-(2-methyl-3-buten-2-yl) monoperoxycarbonate, 
O-(n-octadecyl) O,O-(2-methyl-3-buten-2-yl) monoperoxycarbonate, 
O-(3-methyl-2-buten-1-yl) O,O-(2-methyl-3-buten-2-yl) monoperoxycarbonate, 
O-(2-methoxyethyl) O,O-(2-methyl-3-buten-2-yl) monoperoxycarbonate, 
O-(3-methoxybutyl) O,O-(2-methyl-3-buten-2-yl) monoperoxycarbonate, 
1,2-di[(2-methyl-3-buten-2-yl)peroxycarbonyloxy]ethane, 
1,4-di[(2-methyl-3-buten-2-yl)peroxycarbonyloxy]butane, 
1,12-di[(2-methyl-3-buten-2-yl)peroxycarbonyloxy]dodecane, 
1,8-di[(2-methyl-3-buten-2-yl)peroxycarbonyloxy]-3,6-dioxaoctane and 
1,1,1-tri[(2-methyl-3-buten-2-yl)peroxycarbonyloxymethyl)propane. 
No particular theory being advanced, it seems plausible that in a 
rearrangement reaction the peroxides according to the invention are 
capable of creating epoxide functions: 
##STR9## 
The peroxide according to the invention can be prepared, transported, 
stored and applied as such or in the form of powders, granules, solutions, 
aqueous suspensions or emulsions, pastes, etc. Which of these forms is to 
be preferred partly depends on the case of feeding the peroxide into 
closed systems. Also considerations of safety (desensitizing) may play a 
role. As examples of suitable desensitizing agents may be mentioned solid 
carrier materials, such as silica, chalk and clay, paraffinic 
hydrocarbons, such as isododecane and white spirit, plasticizers, such as 
phthalic esters, and water. 
Modification of (Co)Polymers 
The present peroxides are excellently suitable for use in the preparation 
of epoxide groups-containing (co)polymers, in which process a 
"non-modified" (co)polymer is brought into contact with a peroxide 
according to the invention, upon which the peroxide will entirely or 
almost entirely be decomposed. The peroxide may be brought into contact 
with the (co)polymer in various ways, depending on the object of the 
modification. If, for instance, epoxide groups are to be present on the 
surface of a (co)polymeric object, the peroxide may be applied to the 
surface of the material to be modified. It will often be desirable for 
epoxide groups to be homogeneously distributed in the (co)polymeric 
matrix. In that case the peroxide may be mixed with the material to be 
modified, which material may either be in the molten state or, in the case 
of an elastomer, in the plastic state; to this end use may be made of 
conventional mixers, such as kneaders, internal mixers and (mixing) 
extruding equipment. Should the mixing be impeded by a too high melting 
temperature of the (co)polymer--because of premature peroxide 
decomposition--it is recommended that first of all the (co)polymer in the 
solid state should be provided with epoxide groups (see Example 4), after 
which the modified material is melted and the epoxide groups will be 
homogeneously distributed in the matrix. 
An important practical aspect of the invention is that the moment the 
peroxide and the (co)polymer are brought into contact with each other and 
also the moment the peroxide is to be decomposed can be chosen 
independently of other usual (co)polymer processing steps, such as 
introducing additives, shaping, etc. First of all, for instance, epoxide 
groups may be introduced into a (co)polymer employing a peroxide according 
to the invention and subsequently additives may be introduced, after which 
the product may be mould processed. However, it is also possible, for 
instance, for the peroxide according to the invention to be added to the 
(co)polymer along with other additives and to decompose the peroxide in a 
following shaping step at elevated temperature, such as extrusion, 
compression moulding, blow moulding or injection moulding. In the case of 
(co)polymers that are to be cross-linked, however, care should be taken 
that the peroxide according to the invention is always present in the 
(co)polymer prior to cross-linking. 
Examples of suitable (co)polymers which can be modified by means of epoxide 
groups are saturated (co)polymers, such as polyethylene, e.g. LLDPE, MDPE, 
LDPE and HDPE, polypropylene, both isotactic and atactic, 
ethylene/vinylacetate copolymer, ethylene/ethylacrylate copolymer, 
ethylene/methylacrylate copolymer, ethylene/methylmethacrylate copolymer, 
chlorinated polyethylene, fluorrubber, silicone rubber, polyurethane, 
polysulphide, polyacrylate rubber, ethylene/propylene copolymer, nylon, 
polyesters, such as polyethylene terephthalate and polybutylene 
terephthalate, copolyether esters, poly(butene-1), poly(butene-2), 
poly(isobutene), poly(methylpentene), polyvinyl chloride, polyvinyl 
chloride/vinylacetate graft copolymer, polyvinyl chloride/acrylonitrile 
graft copolymer, and combinations thereof; and unsaturated (co)polymers, 
such as polybutadiene, polyisoprene, poly(cyclopentadiene), 
poly(methylcyclopentadiene), partly dehydrochloridated polyvinyl chloride, 
butadiene/styrene copolymer, acrylonitrile/butadiene/styrene terpolymer, 
ethylene/propylene/dienemonomer terpolymer, isoprene/styrene copolymer, 
isoprene/isobutylene copolymer, isoprene/styrene/acrylonitrile terpolymer, 
polychloroprene, butadiene/acrylonitrile copolymer, natural rubber, and 
combinations thereof. Also combinations of saturated and unsaturated 
polymers can be modified according to the invention. 
It has been found that due to the invention the favourable effect on the 
physical and chemical properties as a result of the presence of epoxide 
groups, which has so far been limited to a relatively small group of 
(co)polymers (see the introductory part of the description), can now also 
be obtained with a large group of other (co)polymers. 
Particularly suitable (co)polymers to be modified by way of the invention 
are polyethylene, polypropylene, ethylene/propylene copolymer, 
ethylene/vinylacetate copolymer, ethylene/propylene/dienemonomer 
terpolymer and butadiene (co)polymers. 
The peroxide according to the invention is generally used in an amount of 
0.01 to 15% by weight, preferably 0.1 to 10% by weight, and more 
particularly 1 to 5% by weight, calculated on the weight of the 
(co)polymer. Use also may be made of combinations of peroxides according 
to the invention. Also of advantage may be the presence of an auxiliary 
peroxide having a decomposition temperature lower than that of the 
peroxide according to the invention. 
The temperature at which the modification is carried out is generally in 
the range of 50.degree. to 250.degree. C., preferably 100.degree. to 
200.degree. C., care being taken then that in order to obtain optimum 
results the duration of the modification step is at least five half-life 
periods of the peroxide. As mentioned above, the (co)polymer may in 
addition to the peroxide contain usual additives. As examples of such 
additives may be mentioned: stabilizers, such as inhibitors against 
oxidative, thermal and UV degradation, lubricants, release agents, 
colorants, reinforcing or non-reinforcing fillers, such as silica, clay, 
chalk, carbon black and fibrous materials, nucleating agents, 
plasticizers, cross-linking agents, such as peroxides such as peroxides 
and sulphur, accelerators and cross-linking coagents, extender oils and pH 
controlling substances, such as calcium carbonate. These additives may be 
employed in the usual amounts.

The invention is further described in the following examples. 
EXAMPLE 1 
Preparation of 2-(t-butylperoxy)-2-methyl-3-butene (peroxide 1) 
To a mixture of 9.3 g of t-butyl hydroperoxide and 8.6 g of 
2-methyl-3-buten-2-ol stirred at 10.degree. C. were added over a period of 
30 minutes 9 g of an aqueous solution of 60% by weight-sulphuric acid. 
Subsequently, the reaction mixture was stirred for 2 hours at 20.degree. 
C. Then 25 ml of water were added. The organic phase was separated and 
washed with aqueous sodium hydroxide and, finally, with water. Obtained 
were 11.2 g of colourless liquid (yield 71%) having a peroxide 1 content 
determined with G.L.C. of 89%. 
Preparation of 2-(2-methyl-3-buten-2-ylperoxy)-2-methyl-3-butene (peroxide 
2) 
A mixture of 21.0 g of 2-methyl-3-buten-2-yl hydroperoxide and 17.2 g of 
2-methyl-3-buten-2-ol was added, with stirring, to 80 g of a solution of 
40% by weight-sulphuric acid in water over a period of 30 minutes and at a 
temperature of 20.degree. C. Subsequently, the reaction mixture was 
stirred for 4 hours at 30.degree. C. After the mixture had been cooled 50 
ml of water and 50 ml of hexane were added. The organic phase was 
separated and washed with aqueous sodium hydroxide and, finally, with 
water. After the hexane had been distilled off under reduced pressure 22.5 
g of colourless liquid were obtained. This liquid was then purified by 
fractional distillation, which resulted in 11.3 g of colourless liquid 
having a peroxide 2 content determined by G.L.C. of 75%. 
Preparation of .alpha.-(2-methyl-3-buten-2-ylperoxy)isopropylbenzene 
(peroxide 3) 
To a mixture of 10.2 g of 2-methyl-3-buten-2-yl hydroperoxide and 11.0 g of 
.alpha.-hydroxyisopropylbenzene stirred at 20.degree. C. was added 1.0 ml 
of an aqueous solution of 5% by weight-perchloric acid. Over a period of 
20 minutes there were then added batchwise MgSO.sub.4.2H.sub.2 O in an 
amount of in all 7.0 g, after which the reaction mixture was stirred for 4 
hours at 40.degree. C. Subsequently, water was added until all the 
magnesium sulphate had dissolved. The organic phase was separated and 
washed with aqueous sodium hydroxide and, finally, with water. Obtained 
were 18.3 g of colourless liquid (yield 100%) having an active oxygen 
content of 6.85% (calculated: 7,26%). 
Preparation of 
1-[.alpha.-(2-methyl-3-buten-2-ylperoxy)isopropyl]-4-isopropenylbenzene 
(peroxide 4) 
The procedure was the same as described above for peroxide 3, except that 
use was made of .alpha.-hydroxyisopropyl-4-isopropenylbenzene instead of 
.alpha.-hydroxyisopropylbenzene. Obtained was a yellow liquid in a yield 
of 92% and an active oxygen content of 5.45% (calculated: 6.15%). 
Preparation of 1,1-di(2-methyl-3-buten-2-ylperoxy)cyclohexane (peroxide 5) 
To a mixture of 20 g of 2-methyl-3-buten-2-yl hydroperoxide and 8.8 g of 
cyclohexanone stirred at 10.degree. C. there were added over a period of 
60 minutes 12.2 g of an aqueous solution of 45% by weight-sulphuric acid. 
Subsequently, the reaction mixture was stirred for 3 hours, the 
temperature being kept at 20.degree. C. by cooling. After addition of 50 
ml of water and 50 ml of heptane the organic phase was separated and 
washed with aqueous sodium hydroxide and, finally, with water. The heptane 
was removed by distillation under reduced pressure at 10.degree. C. 
Obtained were 15.2 g of colourless liquid (yield 59%) of which the active 
oxygen content was 10.0% (calculated: 11.2%). 
Of each of the peroxides 1-5 the structure was confirmed by NMR and IR 
spectroscopic analyses. The temperatures at which the half-life periods of 
decomposition are 10 hours, 1 hour and 0.1 hour are given in Table 1 for 
each of the peroxides 1-5; the measurements were carried out in 0.1M 
solutions in chlorobenzene. 
TABLE 1 
______________________________________ 
Temperature (.degree.C.) for t.sub.1/2 of 
Peroxide 10 hours 1 hour 0, 1 hour 
______________________________________ 
1 110 133 158 
2 107 129 154 
3 106 128 152 
4 114 141 172 
5 74 94 116 
______________________________________ 
EXAMPLE 2 
Preparation of O-(2-ethylhexyl) O,O-(2-methyl-3-buten-2-yl) 
monoperoxycarbonate (peroxide 6) 
To a stirred mixture of 30 g of water, 0.20 moles of 2-methyl-3-buten-2-yl 
hydroperoxide and 0.17 moles of 2-ethylhexyl chloroformate was added over 
a period of 90 minutes and at a temperature of 10.degree. C. 0.20 moles of 
potassium hydroxide in the form of a 45% by weight-aqueous solution of 
potassium hydroxide. Stirring was continued for another 5 minutes. The 
organic phase was separated and subsequently washed with an aqueous 10% by 
weight-potassium hydroxide solution (5 min., 10.degree. C.), an aqueous 
sodium bisulphite solution (15 min., 10.degree. C.) and a dilute solution 
in water of sodium bicarbonate (2.times.). After the organic phase had 
been dried with MgSO.sub.4.2H.sub.2 O, 39.5 g of colourless oil were 
obtained having a peroxide 6 content of 96.3%, corresponding to a yield of 
87%. 
Preparation of O-(n-hexadecyl) O,O-(2-methyl-3-buten-2-yl) 
monoperoxycarbonate (peroxide 7) 
To a stirred mixture of 60 ml of pentane, 0.150 moles of 
2-methyl-3-buten-2-yl hydroperoxide and 0.120 moles of n-hexadecyl 
chloroformate were added, over a period of 30 minutes and at a temperature 
of 8.degree.-11.degree. C., 0.155 moles of potassium hydroxide in the form 
of an aqueous 45% by weight-potassium hydroxide solution. The reaction 
mixture was subsequently stirred for 135 minutes at 8.degree.-11.degree. 
C. The organic phase was separated and successively washed with and 
aqueous 9% by weight-potassium hydroxide solution (10 min., 10.degree. 
C.), an aqueous 9% by weight-sodium bisulphite solution (10 min., 
10.degree. C.) and an aqueous 0.5% by weight-sodium bicarbonate solution 
(10 min., 10.degree. C.). After the organic phase had been dried with 
MgSO.sub.4.2H.sub.2 O, the pentane was evaporated off under reduced 
pressure (0.5 mm Hg) and at 10.degree. C. Obtained was a white, solid 
material containing 94.9% of peroxide 7. The yield was 66%. 
The same procedure was used to synthesize the following peroxycarbonates: 
O-isopropyl O,O-(2-methyl-3-buten-2-yl) monoperoxycarbonate (peroxide 8) 
O-(n-octyl) O,O-(2-methyl-3-buten-2-yl) monoperoxycarbonate (peroxide 9) 
O-allyl O,O-(2-methyl-3-buten-2-yl) monoperoxycarbonate (peroxide 10) 
O-(4-t-butylcyclohexyl) O,O-(2-methyl-3-buten-2-yl) monoperoxycarbonate 
(peroxide 11) 
1,6-di[(2-methyl-3-buten-2-yl)peroxycarbonyloxy]hexane (peroxide 12) 
1,5-di[(2-methyl-3-buten-2-yl)peroxycarbonyloxy]-3-oxapentane (peroxide 13) 
The peroxides 8-13 were all obtained in the form of colourless liquids. 
Of all the peroxides described in this Example the structure was confirmed 
by NMR and IR spectroscopic analyses. Table 2 gives for each product the 
yield, the peroxide content and the temperatures at which the half-life 
period of decomposition is 10 hours, 1 hour and 0.1 hour (0.1M solution in 
chlorobenzene). 
TABLE 2 
______________________________________ 
Yield Content Temperature (.degree.C.) for t.sub.1/2 of 
Peroxide 
(%) (%) 10 hours 
1 hour 
0, 1 hour 
______________________________________ 
6 87 96.3 75 96 120 
7 66 94.9 64 91 125 
8 90 97.9 76 98 123 
9 97 97.0 80 100 124 
10 83 97.3 67 87 110 
11 88 96.3 76 98 123 
12 90 96.5 94 113 135 
13 78 94.5 72 86 102 
______________________________________ 
EXAMPLE 3 
Modification of various (co)polymers with peroxide 6 
In a 50 ml-Brabender blendor 41.6 g of (co)polymer and 4.4 g of peroxide 6 
were intermixed at a speed of 30 rotor revolutions per minute and over the 
periods and at the temperatures given in Table 3 for the various 
(co)polymers. Of the resulting modified (co)polymers the content of 
epoxide groups was determined in the following way. 
In a 250 ml-round bottomed flask about 1 g of product, which had been 
weighed out to the nearest 1 mg, was dissolved with refluxing in 100 ml of 
xylene. After the mixture had been cooled to 30.degree. C., 10,00 ml of a 
solution in 1,4-dioxane of 4N HCl were added, after which the mixture was 
kept at 50.degree. C. for 48 hours. Subsequently, 50 ml of acetone, 50 ml 
of water and 5 ml of 4N nitric acid were added with stirring, after which 
the mixture was titrated potentiometrically, with stirring, with 0.01N 
silver nitrate, use being made of a combined Ag,AgCl electrode. As blanks 
titrations were run on the solvent system used and on solutions of samples 
of the (co)polymers which had previously been treated in the blendor under 
the conditions given in Table 3, but in the absence of peroxide 6. 
The results are mentioned in Table 3. 
TABLE 3 
______________________________________ 
Conditions Epoxide content 
time temp. (mmoles/100 g 
(Co)polymer (hours) (.degree.C.) 
(co)polymer) 
______________________________________ 
polyethylene (Lupolen .RTM. 
1 134-137 10.1 
1810 H, ex BASF) 
ethylene/propylene 
2.5 104-124 4.4 
copolymer (Vistalon .RTM. 
404, ex Esso) 
atactic polypropy- 
2.5 110-111 0.93 
lene (Stamylan .RTM. A-PP10, 
ex DSM) 
ethylene/propylene/diene- 
2.5 109-110 3.4 
monomer terpolymer 
(Keltan .RTM. 740, ex DSM) 
styrene/butadiene co- 
1 106-122 3.3 
polymer (Cariflex .RTM. 
SBR 1500, ex Shell) 
______________________________________ 
To find out whether the epoxide groups were covalently bonded to the 
(co)polymers the following experiment was carried out with the modified 
polyethylene described in this Example. An amount of 1.100 g of the 
material was dissolved with refluxing for 1 hour in 150 ml of xylene. The 
solution while still warm was added to 750 ml of acetone on which the 
polymer precipitated as a fine, white flakelike material. After filtration 
and drying the weight was 0.940 g. Potentiometric analysis showed that the 
epoxide content of the polymer thus purified was 9.7 mmoles/100 g. It may 
therefore be concluded that practically all epoxide groups were covalently 
bonded to the polymer. 
EXAMPLE 4 
Modification of Polypropylene in the Solid State 
In a rotating round bottomed flask 40.5 g of polypropylene powder 
(Moplen.RTM. FLS 20, ex Montepolimeri) were mixed with 4.5 g of peroxide 3 
for 2 hours at 150.degree. C. under a nitrogen atmosphere. The resulting 
product was washed three times for 5 minutes with 500 ml of acetone, after 
which it was dried for 24 hours in vacuo. Potentiometric analysis, carried 
out as described in Example 3, showed that the epoxide content was 4.2 
mmoles/100 g of polymer. 
EXAMPLE 5 
Use being made of ten of the peroxides described in the Examples 1 and 2, 
ethylene/propylene copolymer (Vistalon.RTM. 404) was modified in a 50-ml 
Brabender blendor at 30 rotor revolutions per minute. The amount of 
peroxide in each experiment was 40 mmoles per 100 g of copolymer. For 
peroxide 6 a reaction time of 2.5 hours was used. For the other peroxides 
the duration of the treatment was 1 hour. The temperatures used in the 
blendor for the various peroxides are given in Table 4. Table 4 also 
mentions the epoxide contents of the resulting copolymers, determined as 
described in Example 3. 
TABLE 4 
______________________________________ 
Temperature 
Epoxide content 
Peroxide (.degree.C.) 
(mmoles/100 g copolymer) 
______________________________________ 
1 133-164 7.0 
2 135-155 6.7 
3 130-149 6.9 
5 111-119 7.7 
6 104-124 4.4 
7 118-139 5.8 
8 102-136 6.1 
10 110-117 2.7 
11 111-139 6.3 
13 92-98 1.1* 
______________________________________ 
*The mixture obtained was not homogenous. 
EXAMPLE 6 
Effect of Epoxide Modification on the Mechanical Properties of 
Silica-Filled, Cross-Linked Ethylene/Propylene Copolymer 
For the experiments described in this Example use was made of copolymers 
modified with the peroxides 1 and 6 as described in Example 5. 
100 g of modified copolymer were mixed with 20 g of silica filler 
(Perkasil.RTM. SM500, ex Akzo Chemie), 4.2 g of 
bis(t-butylperoxyisopropyl)benzene (Perkadox.RTM. 14-40 Bpd, ex Akzo 
Chemie) and 1.0 g of triallyl cyanurate (Perkalink.RTM. 300, ex Akzo 
Chemie) on a Swabenthan roll for 5 minutes at 40.degree.-50.degree. C. 
Subsequently, the resulting product was compressed into a 2 mm thick sheet 
(15 min., 180.degree. C., 15 tons), after which the following properties 
were measured: hardness in conformity with ASTM-D2240, tensile strength, 
the 100%, 200% and 300% moduli and the elongation at rupture in conformity 
with ISO-standard R37, type 2 and the tear strength in accordance with 
NEN-standard 5603. 
The results are listed in Table 5, which also gives the results of a 
comparative experiment conducted on unmodified ethylene/propylene 
copolymer. 
TABLE 5 
______________________________________ 
Copolymer 
mod. with peroxide 
Mechanical properties 
1 6 unmodif. 
______________________________________ 
Hardness (Shore A) 
53 51 49 
Tensile strength (MPa) 
7.16 7.42 6.25 
Modulus (MPa) 100% 
1.81 1.37 1.17 
Modulus (MPa) 200% 
4.02 3.30 1.75 
Modulus (MPa) 300% 
6.72 6.20 2.63 
Elong. at rupture (%) 
315 330 575 
Tear strength (N) 
14.2 12.0 13.1 
______________________________________ 
The results given in Table 5 show that, as compared with the product 
prepared using unmodified copolymer, the products according to the 
invention display practically the same hardness, tensile strength and tear 
strength and at the same time display higher modulus values and lower 
elongation at rupture. This clearly points to an improvement of the 
adhesion to the silica filler. 
EXAMPLE 7 
Manufacture of Laminates of Epoxide Modified Polyethylene and Glass Fibre 
or Nylon 
Polyethylene (Lupolen.RTM. 1810 H) was modified with epoxide groups, use 
being made of peroxide 5 and, in another experiment, of peroxide 8. 
The modifications were carried out in a 50 ml-Brabender blendor at 30 rotor 
revolutions per minute over a period of 1 hour. In both experiments the 
amount of peroxide was 40 mmoles/100 g of polymer. In the case of peroxide 
5 the temperature in the blendor was 120.degree.-142.degree. C. and in the 
case of peroxide 8 it was 121.degree.-151.degree. C. Of each of the 
resulting polymers a 1 mm thick sheet was laminated for 30 minutes at 
180.degree. C. to either side of a glass fibre fabric provided with 1383 
finish (ex Silenka). 
Further, of each polymer a 1 mm thick sheet was laminated under the same 
conditions to a 1 mm thick nylon sheet (Akulon.RTM. M258, ex Akzo 
Plastics). 
The laminates were subsequently cooled in a cold press and kept at room 
temperature for 18 hours. Then the peel strength was determined in 
conformity with ISO standard R36 (180.degree.). The results are given in 
Table 6. It also gives the results of comparative experiments carried out 
with unmodified polyethylene. 
TABLE 6 
______________________________________ 
Peel strength (N/cm) 
Polyethylene glass fibre 
nylon 
______________________________________ 
modified with peroxide 5 
2.76 0.10 
modified with peroxide 8 
3.12 1.97 
unmodified 1.33 0.01 
______________________________________ 
The data of Table 6 clearly show that the laminates according to the 
invention display a considerably better adhesion than the laminates made 
by using unmodified polyethylene. 
Such improved adhesion is of great importance to the preparation of 
(co)polymeric blends (see also Examples 9 and 10) and glass-fibre filled 
(co)polymers, because the resulting materials exhibit enhanced impact 
resistance. The use of the (co)polymers modified according to the 
invention also results in improved adhesion to other reinforcing 
materials, such as yarns, cords and fabrics. It should be added that 
(co)polymers modified according to the invention in combination with nylon 
may with advantage be applied in the manufacture of co-extruded films. 
EXAMPLE 8 
Adhesion of a Coating to Epoxide Modified Polyethylene 
Polyethylene (Lupolen.RTM. 1810 H) was modified with peroxide 5 and, in 
another experiment, with peroxide 8 in the way described in the fist part 
of Example 7. Each resulting polymer was compressed into a sheet 1 mm 
thick over a period of 15 minutes and at a temperature of 130.degree. C. 
Subsequently, of each sheet the adhesion to it of a coating was tested as 
follows. Each sheet was cut into 2 strips measuring 5 cm.times.2 cm. On 
one side each strip was at one end and over a total surface area of 
11/2.times.2 cm.sup.2 covered with a coating of the following composition: 
20 g of Epikote.RTM. DX 235 (bisphenol A/F epoxy resin, ex Shell) 
12 g of Epilink.RTM. 177 (polyaminoamide, ex Akzo Chemie) 
0.3 g of Silane.RTM. A1100 (.gamma.-aminopropyl triethoxy silane, ex Union 
Carbide). 
The coated ends of every two strips were clamped together in a screw clamp 
and kept at 50.degree. C. for 24 hours. Subsequently, the bonding strength 
was determined by measuring the force needed to separate the strips by 
means of a Zwick tensile tester. 
The results are given in Table 7, which also mentions the results of a 
comparative experiment conducted with unmodified polyethylene. The results 
clearly show that the adhesion obtained with the modified polymers 
according to the invention is greater than that with the unmodified 
polyethylene. 
TABLE 7 
______________________________________ 
Polyethylene Bonding strength (N/cm.sup.2) 
______________________________________ 
modified with peroxide 5 
18.8 
modified with peroxide 8 
28.6 
unmodified 13.7 
______________________________________ 
EXAMPLE 9 
Blend of Epoxide Modified Polyethylene and a Co-Reactive Polymer 
Polyethylene (Lupolen.RTM. 1810 H) was modified with peroxide 6 via epoxide 
groups in the way described in Example 3. The resulting material was mixed 
with acrylic acid-modified polyethylene (Primacor.RTM. 1430, ex Dow 
Chemical) in a weight ratio of 1:1 in a Brabender blendor for 30 minutes 
at 120.degree. C. and 30 rotor revolutions per minute. Of the resulting 
blend the apparent melt viscosity was determined in a Gottfert High 
Pressure Capillary Rheometer, type 2001, at 190.degree. C. and a shear 
rate of 14.4s.sup.-1. The result is given in Table 8, which also mentions 
the apparent melt viscosities, measured under the above conditions, of a 
1:1 blend of unmodified polyethylene and Primacor.RTM. 1430, which blend 
was prepared in the same way as described in this Example for the blend 
according to the invention, and of the respective starting polymers. 
TABLE 8 
______________________________________ 
Apparent 
melt viscosity 
Polymer or blend (Pa.s) 
______________________________________ 
modified polyethylene/Primacor .RTM. 1430 
6.6 .times. 10.sup.3 
unmodified polyethylene/Primacor .RTM. 1430 
1.9 .times. 10.sup.3 
modified polyethylene 8.5 .times. 10.sup.3 
unmodified polyethylene 
2.6 .times. 10.sup.3 
Primacor .RTM. 1430 1.4 .times. 10.sup.3 
______________________________________ 
As appears from the data in Table 8, the apparent melt viscosity of the 
modified polyethylene/Primacor.RTM. 1430 blend is a factor of 1.33 higher 
than the average apparent melt viscosity of the modified polyethylene and 
the Primacor.RTM. 1430. Such an increase is distinctly indicative of the 
occurrence of strong interaction of the two polymers, which has a 
favourable effect on the material properties, such as form stability at 
elevated temperature, resistance to solvents, and impact resistance. 
It should be added that both the modified polyethylene and the blend of 
this material with Primacor.RTM. 1430 can be processed by usual extrusion 
and injection moulding techniques, despite the increased apparent melt 
viscosity due to the epoxide modification according to the invention. 
Finally, general attention is drawn to the advantages offered by the 
interaction of epoxide modified (co)polymers and co-reactive polymers in 
the manufacture of co-extruded film. 
EXAMPLE 10 
Blend of Epoxide Modified Ethylene/Propylene Copolymer and Nylon 
For the experiment described in this Example use was made of 
ethylene/propylene copolymer modified with peroxide 5 as described in 
Example 5. This material was mixed with nylon (Akulon.RTM. M258) in a 
Brabender blendor over 30 minutes at 30 rotor revolutions per minute and 
at a temperature of 235.degree. C. The weight ratio between the modified 
copolymer and nylon was 1:5. Subsequently, the resulting blend was 
compressed into sheets 2 mm thick at a temperature of 260.degree. C., 
after which the tensile strength, the rupture strength and the elongation 
at rupture were determined in conformity with ISO standard R37, type 1. 
The results are given in Table 9, which also mentions the results of a 
comparative experiment conducted on unmodified ethylene/propylene 
copolymer. 
TABLE 9 
______________________________________ 
Mechanical Blend of nylon with 
properties mod. copolymer 
unmod. copolymer 
______________________________________ 
Tensile strength 
39.3 39.2 
(MPa) 
Rupture strength 
42.9 35.8 
(MPa) 
Elong. at rupture 
42 16 
(%) 
______________________________________ 
The data in Table 9 clearly show that as compared with the blend prepared 
using unmodified copolymer the blend according to the invention displays a 
higher rupture strength and a higher elongation at rupture. So the blend 
according to the invention has a higher toughness, and consequently a 
higher impact strength.