CA1126439A - Poly(hydroxy) telechelic styrene polymer process - Google Patents

Abstract

ABSTRACT OF THE DISCLOSURE

A poly(hydroxy) telechelic styrene polymer polymeric zation process comprising contacting an olefin, a free radical polymerization initiator, and a poly(hydroxy-organo) polysulfide is described. The poly(hydroxy) terminated styrene polymers can be end-capped and/or coupled with other polymeric materials. The styrene polymers can be molded, calendered, or extruded as films, sheets, fibers, laminates or other useful articles of manufacture.

Description

~ RD-10,772 This invention relates to a telechelic styrene poly-merization process which comprises contacting an olefin, a free radical polymerization initiator and a poly-(hydroxyorgano) polysulfide or a silylated derivative thereof. The poly(hydroxyorgano) or siloxy organo ter-minated styrene polymers can be end-capped and/or coupled with other polymeric materials. ~he styrene polymers can be molded, calendered, or extruded into films, sheets, fibers, laminates or other useful articles of manufacture.
The polymerization of styrene either alone or in the presence of other copolymerizable monomers i5 well-know.
In general the polymerization of styrene is described in terms of various reaction mechanisms including free radical initiation, propagation, chain transfer and termination reaction mechanisms.
~eretofore, to the best of my knowledge, the polymeric-zation of styrene to form homopolymers or copolymers with other copolymerizable monomers has not been carried out in the presence of poly(hydroxyorgano) polysulfides or their silylated derivatives. These compounds perform two functions, i.e. (I) act as effective chain transfer agents and (II) form reactive hydroxy or siloxy organo polystyrene end groups.
Although various radical polymerization and sulfur chemistry texts generally state that (a) "some organic disulfides via homolytic dissociation function as polymerization initiators", (b) "some mono- and disulfides, e.g.
RSR and RSSR compounds dissociate to radicals either photochemically or thermally at moderate temperatures, and have been used as initiators of ~ RD-10,772 polymerization 'and', in some cases, compllcations arise from transfer to initiator which may be accompanied by retardation", and (C) "that mercaptans as ~ell as aryl-disulfides act as chain transfer agents during the polymerization of styrene", I believe in view of the absence of known scientific evidence describing the reactions of poly(hydroxyor~ano) and siloxyorgano polysulfides in the polymerization of styrene polymers under Eree radical polymerization reaction conditions that my observation that such poly-sulfides are effective chain transfer agents and also provide polyfunctional reactive end groups for styrene polymers is unobvious.
This invention embodies a poly or siloxyorgano telechelic styrene polymerization process comprising contacting an olefin, a free radical polymerization initiator, and a poly (hydroxyorgano) polysul~ide or its silylated derivative. The thus formed styrene polymers can be end-capped and/or coupled with other polymeric materia]s~
The styrene polymers can be molded, calendered, or extruded as films, sheets, fibers, laminates or other useful articles of manufacture.
The expression "olefin" as employed herein and in the claims includes any free radical polymerizable olefin.
Illustratively olefins includes styrene; o-, m- and p-methylstyrene; 2,4-dimethylstyrene; 2,5-dimethylstyrene;
3,4-dimethylstyrene; 3,5-dimethylstyrene; p-ethylstyrene;

p-isopropylstyrene; p-cyclohexylstyrene~ o-, m- and/or p-fluorostyrene; 2-methyl-4-fluorostyrene; m- and p-chlorostyrene; p-bromostyrene; l-vinylnaphthalene; 2-~2~3~ RD-10,772 vinylnaphthalene; l-vinyl-4-chloronaphthalene; 6-vinyl-1,2-3,4-tetrahydronaphthalene; 4-vinylbiphenyl and 9-vinylphenanthrene, etc. Olefin monomers are commonly referred to as "vinyl aromatic monomeric reactants" and said monomers can be copolymerlzed with other well-known olefinic materials in the preparation of various copolymers including --- however not limited to --- styrene-acrylonitrile; styrene-butadiene-acrylonitrile; styrene-butadiene; styrene-divinyl benzene; styrenemaleic anhydride; styrene-methyl methacrylate; styrene-vinyl acetate; styrene-isoprene, etc., copolymers.
In a presently preferred embodiment the "vinyl aromatic monomers" employed in the formation of homo- or co-polymers of s yrene are of the formula:
(I) ~C - CH2 ~ Z (P) wherein independently R is hydrogen, lower alkyl or halogen, Z is a member selected from the class consisting of vinyl, hydrogen, chlorine and lower alkyl, and p is a whole number equal to from 0 to 5.
The expression "free radical polymerization initiator"
as employed herein and in the claims includes any free radical polymerization initiator. Illustratively free radical polymerization initiatox include peroxides, per-sulfates, hydroperoxides, peresters, azo compounds, photo-initiators, etc. Those skilled in the art known that the type of free radical initiator employed can vary depending upon the particular type of polymer or copolymer being prepared since certain free radical species are more effective in polymerization of certain olefins, e.g.
styrene, than others which are more effective in co-RD-10,772 ~12~

polymerizing styrene with other monomer types, e.g.
methylmethacrylate. ~ccordingly, selection of the ap-propriate free radical i.nitiators will be apparent or can be readily determined by routine experimentation by those having ordinary skill in the art. By way of illustration, generally useful free radical polymerization initiators include the following: methyl peroxide; ethyl peroxide; propyl peroxide; isopropyl peroxide; tert-butyl peroxide; l-hydroxybutyl-n-butyl peroxide; tert-amyl peroxide; tert-butyl-d -cumyl peroxide; 2,5-dimethyl-

2,5-di(tert-butylperoxy)hexane; n-butyl-4,4-bis(tert-butylperoxy)valerate; cumyl peroxide; acetyl peroxide;
propionyl peroxide; butyryl peroxide; succinoyl peroxide;
benzoyl peroxide; 4-bromobenzoyl peroxide; 3,5-dibrome-4-methoxybenzoyl peroxide; phenylacetyl peroxide; 5-phenyl-valeryl peroxide~ lauroyl peroxide; myristoyl peroxide;
tert-butyl hydroperoxide; cumene hydro-peroxide; tetralin hydroperoxide; tert-butyl peracetate; ethyl tert-butyl peroxlate; di(tert-butylperoxy)-oxalate; tert-butyl perbenzoate; tert-butyl-N-(3-chlorophenylperoxy) carbamate;
tertbutyl 2-methylsul~onylperbenzoate, tert-butyl 4-(methylthio)-perbenzoate; tert-butyl phenylperacetate;
tert-butyl 4-tertbutylperbenzoate; 2,2'-azo-bis-isobuty-ronitrile; 1, l'-azo-bis-l-cyclobutanenitrile; 4,4'-azo-bis-4-cyanopentanoic acid; 2,2'-azo-bis-2,4-dimethylval-eronitrile; 1, l'-azo-bis-l-cycloheptane nitrile; 2,2'-azo-bis-2-cyclohexylpropionitrile; l,l'-azo-bis-l-cyclo-decane nitrile; 2,2'-azo-bis-propane; triazobenzene; azo-bis-isobutyramidine; l,l'-azo-bis-l-phenylethane; 1, 1'-azo-bis-l-phenylpropane; phenyl-azo-triphenylmethane; azo-bis-diphenylmethane; and 4-acetaminophenyl-azo-triphenyl-methane.

RD-10,772 ~Z~3~
The expression "poly(hydroxyorgano) polysulfide" as employed herein and in the claims includes illustratively any polysulfide of the formula:

(H0 ~ R'-~S~n--R' ~ ~

wherein independently each x is an integer at least equal to 1, n is an integer at least equal to 2, R' is at least a divalent arene radical having a~ least one hydroxyl (-OH) radical directly bonded to an aromatic ring carbon atom via the oxygen atom of the hydroxyl group.
In a presently preferred embodiment, R' contains 6-30 carbon atoms. In a still more preferred embodiment, R' is a C6 10 aryl or aralkyl radical, x is equal to 1, an~ n is equal to 2.
Illustratively preferred polysulfides include bis-(4-hydroxyphenyl)disulfide, bis (4-hydroxyphenylmethylene)-disulfide, bis(4-hydroxyph~nylethylene)disulfide, and bis(4-hydroxynaphthylene)disulfide, etc.
rne silylated derivatives of th~ hydroxy organo polysulfides of formula II have the formula (111) ~3S~ O - R'- ~S]n - R' - ~Si ~

Where R',n and X are as above defined and R is a hydro-carbyl radical such as alkyl, aycloalkyl or aryl, aycloa-lykl or aryl radical or a combination of such radicals.
In a presently preferred embodiment, R contains 1-30, and R' contains 6-30 carbon atoms. In a still more preferred embodimentr R is a Cl 15 alkyl radical, R is a C6 10 aryl or aralkyl radical, x i5 equal to 1, and n is equal to 2.
Illustratively preferred polysulfides of formula ~ 3~ RD-10,772 III are bis (e-trimethylsiloxyphenyl)disulfide, bis(4-trimethylsiloxypheenylmethylene)disulfide, bis (4-tri-t- butylsiloxyphenyl)disulfide, bis(4-triphenylsiloxy-phenylethylene)disulfide, and bis (4-tripentylsiloxyna-phthylene)disu:LEide, etc.
The polymerization process can be carried out employing any conventional polymerization technique for producing styrene homo- and copolymers, e.g. bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, continuous bulk/solution poly-merization, etc. Polymerization reaction temperatures can be any reaction temperatures in which the polymerization reaction takes place, e.g. O C. or less to 150C. or more~
and preferably from 25 C. to about 100 C. ~roadly, the reaction time varies with quantity of reactant as well as the life of the free radical initiator employed, how-ever basicly the reaction time can be any time, e.g.
from about l/10 hr. or less to 10 hours or more. Those skilled in the art can readily determine the appropriate reaction time and temperatures through routine ex-perimentation.
The following examples illustrate the best mode of the invention. Example I and II illustrate the use of polyhydroxyorganopoly sulfide agents and Examples III and IV their Sil derivatives including the preparation of such derivatives.
EXAMPLE I - Preparation of Bis(4i-hydroxyphenyl) disulfide A solution of 4~mercaptophenol (2n~ g., 1.6 m ) in 300 ml. 60% aqueous ethanol was brought to pH 7 by the addition of sodium bicarbonate. A solution of iodine (200 g., 0.~ m.) and potassium iodide (50 g.) in 300 ml.

- ~ ~f~ RD-10,772 water was added until a yellow end point was reached.
The product was filtered off, washed with water and dried.
Yield: 97. 5%, mp. 144-6 (lit. 148-50 ). The H nmr was consistent with the disulfide structure of the formula:

HO~S-S~OH

EXAMPLE II - Preparation of Poly(hydroxyorgano) Telechelic ' ~ ' Styrene Polymer Styrene (lOO gms., 0.96 mole, freshly,distilled~, azo-bisisobutyronitrile (0.05 gms.~ and bis (4`~,hydroxy-phenyl)- disulfide (3.71 gms., 0.0148 mole~ in a 4 oz.
screw-cap bottle under nitrogen was heated at 50 ~ 3.
A stirring bar was used to agitate the mixture since the disulfide was not com,pletely soluble in the styrene.
After 4 days the viscous liquid ~as dissolved in toluene and the polymer was precipitated by dropwise addition to methanol. The polymer was filtered off, dried, then redissolved in toluene and washed with 12~ aqueous sodium h~ e~-, dilute acetic acid an~ three times with water.

The solution was added dropwise to toluene and the polymer again was reprecipitated from toluene by methanol. After ' drying the product weight 23.4 g. Intrinsic viscosity in chloroform at 25: 0.52 dl./g. Infrared: 3594 cm.
~absorbance for 500 mg. /10 ml. CS2 was 0~176). The product structure is of the formula:

, .

H0 ~ - S ~ H-CH2 ~ S ~ OH
J m .

11264~9 RD 10,772 m being a number average within the range of from about 600 to 800.
EXAMPLE III - Preparation of Bis(4-trimethylsiloxyphenyl)-disulfide.
Hexamethyldisilazane (19.4 grms., 0.12 mole was was added to solid bis(4-hydroxyphenyl)disulfide (20 gms., 0O08 mole). The reaction began immediately given a clear liquid. After 4 hours excess hexamethyldisilazane was removed by warming and evaporation. Gas chromatography showed no starting disulfide and only a trace of mono-hydroxy disulfide. The liquid product crystallized on cooling at 5 C. m.p. 21-22. The lH nmr was consistent with a disilylated disulfide of the formula:

~H3C~--Si~o_ ~ -S S- ~ -O~Si-(CH3) EXAMPLE IV - Preparation of Poly(trimethylsiloxyltelechelic Styrene Poly~er Styrene (100 gms., 0.~6 mole, freshly distilled~, azobisisobutyronitrile (0.05 gms.) and bis(4-trimethyl-siloxyphenyl) disulfide (5.83 gms., 0.15 mole) were heated under nitrogen in a 4 Oz. screw-cap bottle for seven days at 50 ~ 3 C. The clear viscous liquid was diluted with toluene and precipitated by adding to 500 ml.
methanol containing a solution of 2 gms. calcium nitrate in 50 ml. ethanol in a stirred blender. The polymer was filtered off, dried, and reprecipitatPd as above, then dried, redissolved in toluene and precipitated by drop-wise addition into a 3.1 of methanol containing 1 ml.
conc. hydrochloric acid. After filtering and drying, the polymer weighed 50.4 gms., exhibited an intrinsic viscovity (measuxed in chloroform at 25C.) of 0.20 dl./g., and an infrared absorbance at 3590 cm. 1 of RD-10,772 0.238 (500 mg./10 ml. CS2).

(H3C~--Sl 0--~--S~ H-CH2 ~ ~ 0-Si~CH3) 15 m being a number average of within the range of rom ,about 150 to 250.
. The poly hydroxyorgano or siloxyorgano telechelic styrene polymers prepared in accordance with the process of this invention -- being bifunctional - - can be -advantageously combined with the novel bifunctional quinone-coupled polyphenylene oxides described in my Canadian patent application Serial No. 309,632, filed August 18, 1978. Because of the reactive bifunctional character of the novel polystyrene polymers prepared by the process of this inventionl novel polystyrene-polyphenylene oxide block polymers claimed in my Canadian~ patent application Serial No. ~9,~ filed~r~ne ~3, /~7~ can be prepared which are useful in a wide variety of articles of manufacture.

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Claims (11)

RD-10,722 The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A polymerization process comprising contacting an olefin, a free radical polymerization initiator, and a polysulfide selected from poly(hydroxyorgano) polysulfide and poly (siloxyorgano) polysulfide.

2. The process of claim 1 wherein the olefin is a vinyl aromatic monomeric reactant

3. The process of claim 2 wherein the initiator is selected from the group consisting of peroxides, per-sulfates, hydroperoxides, peresters, azo compounds and photoinitiators.

4. The process of claim 1, 2 or 3 wherein the polysulfide is of the formula , wherein independently each x is an integer at least equal to 1, n is an integer at least equal to 2, R' is at least a divalent arene radical having at least one hydroxyl (-OH) radical directly bonded to an aromatic ring carbon atom via the oxygen atom of the hydroxyl group.

5. The process of Claim 1, 2 or 3 wherein the polysulfide is of the formula wherein independently each x is an integer at least equal to 1, n is an integer at least equal to 2, R is alkyl, cycloalkyl, or aryl radical including combinations thereof, and R' is at least a divalent arene radical having at least RD-10,772 a divalent arene radical having at least one organosiloxy radical directly bonded to an aromatic ring carbon atom via the oxy radical of the siloxy group.

6. The claim 1, 2 or 3 process wherein the vinyl monomer is of the formula (p) wherein independently R is hydrogen, lower alkyl, or halogen, Z is a member selected from the class consisting of vinyl, hydrogen, chlorine and lower alkyl, and p is a whole number equal to from 0 to 5.

7. The process of claim 1, 2 or 3 wherein the free radical polymerization initiator is an azo compound .

8. The process of claim 1, 2 or 3 wherein the polysulfide is bis (4-hydroxyphenyl) disulfide.

9. The process of claim 1, 2 or 3 wherein the polysulfide is bis (4-trimethylsiloxy phenyl) disulfide.

10. The process of claim 1, 2 or 3 wherein said olefin is styrene.

11. A styrene telechelic polymer prepared by the process of claim 1, 2 or 3.