CA1316768C - Method of sealing joints and cracks in concrete or asphalt with organic terminated polysulfide polymers - Google Patents

Abstract

ABSTRACT
A method of sealing cracks and joints in concrete or asphalt structures is disclosed. The cracks or joints are sealed with a sealant which is an organic-terminated polysulfide polymer represented by the formulae I and II
wherein n is a number from 2 to 8, 1 is zero or a positive integer, m is a positive integer, each R is independently an unsubstituted or inertly substituted organic polyradical with the radicals residing in carbon atoms, p is zero or a positive number which is the difference between the number of valence of R and 2, and each Y and Z is independently chosen from the class consisting of (vinylaryl)alkyl and other inertly substituted noncross-linking monoradicals provided that at least a portion of Z is (vinylaryl) alkyl.

Description

1 3 1 67 ' 3 This invention is divided out of parent application Serial No. 500,6g4, filed on January 30, 1986. This divisional application relates to methods of sealing joints and cracks in concrete or aspha]t with organic terminated polysulfide polymers.
The invention of the parent application relates to blends of organic polymers and organic-terminated polysulfide polymers. The organic polymer may be a saturated organic elastomer, an ethylenically unsaturated organic elastomer, a non-elastomeric polymer, or any combination blend of the three.
The organic-terminated polysulfide polymer may be curable, non-curable or any blend thereof.
Curable organic-terminated polysulfide polymers are useful as the primary ingredient or as an additive in sealants, adhesives and like compositions as well as for preparing diverse solid articles as gaskets, hoses, tubing and the like.
While such polysulfide polymers are generally quite suitable for these and other uses, it is often desirable to modify said polysulfide polymers in order to impart specific desirable properties thereto. For ~ ~ 2 ~
1 31 67~i~

example, in a sealant or adhesive application it is often desirable to employ a polymer which has greater resilience and/or cohesive strength than is commonly exhibited by said polysulfide polymers, while maintaining the adhesion and resistance to water, solvents and ultraviolet light characteristic of polysulfide pol~mers.

Unfortunately, most conventional polysulfide polymers, particularly in the cured state, are insoluble in most solvents and incompatible with organic polymers.
Accordingly, it is usually difficult to formulate such conventional polysulfide polymers with other polymers or even with common additives for polymeric compositions.

Accordingly it would be desirable to provide a polysulfide polymer composition which exhibits improved 15 physical properties, particularly improved resilience, recovery, compression set, and lower mo~ulus while maintaining general polysulfide properties.

In the building and maintenance of concrete or asphalt roads, sidewalks, highways, driveways, and the like, it is often required to employ a sealant to connect joints between adjacent segments of the struc-ture or to repair cracks or small holes therein. Such sealants prevent the incursion of water, ice, sand, salts, oils, and the like into cxacks and joints of the concrete or asphalt. Such sealants must exhibit several properties to be entirely satisfactory. The sealant must adhere well to concrete or asphalt. The sealant must also maintain its strength and adhesive properties over a wide range of temperatures and in dry as well as wet and icy conditions. In addition, the sealant is desirably resistant to UV light, ozone and organic 31,939B-F -2-_ 3 _ 1 3 1 6 7 ~ 3 64693-3743D
liquids, such as gasoline and motor oil. Furthermore, the seal-ant must exhibit good cohesive strength and resilienee and be capable of withstanding movements in the cement or asphalt substrate to which it is adhered.
The most commonly used sealants are asphalt-based sealants such as rubberized asphalt and coal tar sealants such as urethane-coal tar sealants and polyvinyl chloride-coal tar sealants. Such sealants are often poor in adhesion to the con-crete or asphalt substrate and do not have a useful life that is as long as desired. In concrete highways, joints sealed with asphalt-based adhesives commonly fail within 3 to 6 months after application. Such early failure of the sealant leads to greatly decreased service life of the pavement.
In addition to poor adhesion, many conventional sealants also exhibit greater cohesive strength than adhesive strength. Accordingly, when the concrete or asphalt substrate moves slightly, the adhesive bond to the substrate is often ruptured.
It would be desirable to provide an adhesive for cement or asphalt structures which exhibits good adhesion to both concrete and asphalt structures, resistance to weather changes, and which forms a bond to the substrate which is not ruptured upon small movements of said substrate.
According to one aspect of the invention of the parent application there is provided a polymer composition comprising a blend of at least one organic-terminated polysulfide polymer and ~ 4 ~ 1 3 1 6 7 ~ , 64693-3743D

an organic polymer which is not an organic-terminated polysulfide, characterized in that said polysulfide polymer is represented by the general formulae Z-[SnR]m-Sn-Z Y-[S R] -S -Y
I nl m n II
- ~SnR)l~Sn~Z]p and ~ S R)l-S -Y]

wherein n is a number from 2 to 8, 1 is zero or a positive integer, m is a positive integer, each R is independently an unsubstituted or inertly substituted organic polyradical with the radicals residing in carbon atoms, p is zero or a positive number which is the difference between the number of valence of R and 2, and each Y and Z are independently chosen from the elass consisting of (vinylaryl)alkyl and other inertly substituted noncross-linking monoradicals provided that at least a portion of Z is (vinylaryl) alkyl; said organic polymer is an ethylenically unsaturated elastomer, a saturated organic elastomer, a non-elastic organic polymer or the mixture thereof, and said organic-terminated poly-sulfide polymer is present in an amount of from 1 to 99 percent by weight based on a total weight of the polymers in the blend.
According to another aspect of the invention of the parent application there is provided a method of sealing cracks or joints in concrete or asphalt structures by applying the polymer composition defined above as the sealant in an amount sufficient to seal the cracks or joints.
According to the invention of the present divisional application there is provided a method of sealing cracks or joints in concrete or asphalt structures by applying a sealant to said 13167~J2~

cracks or joints characterized in that at least one organic-terminated polysulfide polymer represented by the plural formulae Z~[SnRlm~Sn~Z Y-lSnR~ Sn~Y II

~S R) -S -Z] and ~S R) -S -Y]

wherein n is a number from 2 to 8, 1 is zero or a positive integer, m is a positive integer, each R is independently an unsubstituted or inertly substituted organic polyradical with the radicals residing in carbon atoms, p is zero or a positive number which is the difference between the number of valence of R and 2, and each Y and Z is independently chosen from the class consisting of (vinylaryl)alkyl and other inertly substituted noncross-linking monoradicals provided that at least a portion of Z is (vinylaryl) alkyl, is employed as the sealant in an amount sufficient to seal said cracks or joints.
Surprisingly, it has been found that such organic-terminated polysulfide polymer can be blended, even in the cured state, with an organic elastomer that contains a measurable amount of ethylenic unsaturation (i.e. nonconjugated carbon-carbon double bonds). Also surprising is that the resulting blcnds are stable and do not tend to phase separate or exhibit other unde-sirable characteristics of blends of incompatible polymers. These blends also exhibit improved physical properties such as tensile strength and resilience as compared to the corresponding organic-terminated polysulfide polym~r alone. Thus, in one aspect the invention of the parent application is a blend of at least one aforementioned organic-terminated polysulfide polymer and an 1 31 67 ',3 ethylenically unsaturated organic elastomer.
Another aspect of the invention of the parent applica-tion is a polymer composition which comprises a blend of at least one aforementioned organic-terminated polysulfide polymer and a saturated organic elastomer. These blends with the saturated organic elastomers are stable and exhibit improved physical proper-ties as compared to the organic-terminated polysulfide polymer alone.
In yet another aspect of the invention of the parent application, at least one aforementioned organic-terminated poly-sulfide polymer is blended with a non-elastomeric organic polymer.
These blends are also stable and exhibit improved physical proper-ties as compared to the organic-terminated polysulfide polymer alone.
Still in another aspect, the invention of the parent application is an improved method for sealing cracks or joints in concrete or asphalt structure by applying thereto as a sealant the polymer compositlon of the invention of the parent application.
The composition comprises a blend of at least one organic-terminated polysulfide polymer (hereinafter "polysulfide polymer") and an organic polymer. The organic polymer is either an ethylenically unsaturated organic elastomer (hereinafter "unsaturated organic elastomer"), a saturated organic elastomer, a non-elastomeric organic polymer or a blend of any combination of the three~ The relative proportions of polysulfide polymer and organic polymer can be within any range wherein the polysulfide - 6a - 1 31 6 7 '\J 3 64693-3743D

polymer and organic polymer are compatible. Compatability, is generally evidenced by a lack of phase separation in the blend.
Generally, the blends contain from 1 to 99 weight percent polysul-fide polymer, based on a total weight of the polymers in the blend.
The polysulfide polymer is a polymer of a metal sulfide, a copolymerizable polyfunctional organic compound and a copoly-merizable monofunctional compound which gives rise to unsubstituted or inertly substituted organic-terminal groups. Said mono-functional organic compound advantageously contains a (vinylaryl) alkyl moiety in which case the resulting polysulfide polymer will be curable. Alternatively, the monofunctional organic compound will not contain any vinyl unsaturation, and the resulting poly-sulfide will not be curable.
Suitable curable polysulfide polymers are described in United States Patent No. 4,438,259. Such a curable polysulfide polymer is a copolymer represented by the general formula.

Z~ [SnR]m-Sn-Z

~SnR) 1 Sn Z ] p J ~7~ 1 31 67 G~

wherein n is a number from 2 to 8, 1 is zero or a positive number, m is a positive number, each R is independently an unsub~tituted or inertly substituted organic polyradical with the radicals residing on carbonlatoms, p i~ zero or a positive number which is the difference in the number of valence of R and 2, and each Z is independently chosen from the class consist-ing of (vinylaryl)alkyl and other inertly substituted non-crosslinking monoradicals, provided that a suffi-cient proportion of the terminal groups of said copoly-mer are (vinylaryl)alkyl so that said copolymers are curable.

In said curable elastomeric polysulfide, the terminal group Z is preferably an unsubstituted or inertly substituted vinylbenzyl group or a mixture thereof with an unsubstituted or inertly substituted non-crosslinking group, particularly a benzyl group.
For the purpose of the invention, "inertly substituted"
means that the radical contains no moieties which interfere with the preparation or subse~uent curing of the elastomer.

The polyradicals are polyfunctional organic radicals in which the radicals reside on carbon atoms, i.e., the adjacent polysulfide linkages are bonded to a carbon atom on the organic polyradical. The R groups may be hydrocarbon, such as ethylene, propylene and like radicals, may contain hetero atoms such as ether linkages or may contain other inert substituent groups.

In the polysulfide linkages Sn, the sulfur link or average length of the sulfur chain is generally from 2 to 8, and is preferably from 2 to 5 sulfur atoms.

31,939B-F -7-1 3 1 67 '` ~', Of the foregoing structural components of the polymer, the polysulfide linkages are primarily responsible for properites such as good adhesion and resistance to water, resistance to ultra-violet light and the like. When the sulfur link is 3 or greater, the sulfur linkages also impart flexibility to the polymer. The organic polyradical often imparts flexibility and elongation to the elastomer. When the organic polyradical has a valence of 3 or more (i.e.l a branched polymer is formed (S4)), high modulus and low cold flow are imparted to the polymer. The terminal groups Z
impart curing characteristics and the desired molecular weight.
The curable polysulfide polymers preferably contain from 50 to 85 percent, more preferably 70 to 80 percent by weight sulfur and have a molecular weight, prior to curing, of 1,500 to 50,000, preferably 4,000 to 25,000, more preferably 4,000 to 12,000. It is further desirable that the curable polysulfide poly-mer contains a proportion of nonvinyl-group-containing terminal groups. Preferably, from lO to 75 percent of said terminal groups do not contain vinyl moieties.
Said polymers are advantageously prepared according to the methods described in United States Patent No. 4,438,259. In a preferred method, the polymers are prepared by reacting a metal sulfide with elemental sulfur to prepare a metal polysulfide. The metal polysulfide is then reacted with at least one organic compound having a plurality of negatively charged functional groups which will split off upon reacting with a metal polysulfide, and a monofunctional (vinyl-aryl)alkyl compound which upon reacting gives rise to the desired terminal groups.
.

The metal polysulfide may be prepared by heating to reflux a mixture of a dissolved metal mono-sulfide, especially sodium sulfide an^d elemental sulfur.
The metal polysulfide is subsequently reacted with the organic components by forming a mixture emulsion of the metal polysulfide (in agueous solution) and the organics and heating to 25 to 90C for 5 minutes to 2 hours.

Alternatively, the polysulfide polymer may be a noncurable polysulfide polymer. Such noncurable polysulfide polymer contains organic-terminal groups, of which none or only a small amount are (vinylaryl)-alkyl. By "a small amount", it is meant that thenoncurable polymer contains a proportion of (vinylaryl)-alkyl terminal group which is less than the amount which enables the polymer to significantly cure.
Examples of such noncurable polysulfide polymers are - 20 represented by the general formula:

Y~[SnR~ ~Sn_y II
S R)l-S -Y]

wherein n is a~number from 2_to 8, 1 is ze~ro or a positive number, m is a posit1ve number, each R is independently an unsubstituted or inertly substituted organic polyradical with the radicals residing on carbon atoms, p is zero or a positive number which is the difference in the number of valence of R and 2, and 31,939B-F _g_ each Y is independently chosen from the ciass consist-ing of (vinylar.yl)alkyl and other inertly substituted non-crosslinking organic monoradicals, provided that the proportion of the terminal groups which are (vinyl-aryl)alkyl is less than that amount which enables thepolymer to significantly cure. By "less than that amount which enables the polymer to significantly cure", it is meant that the polysulfide polymer, when fully "cured" by heating, is capable of cold flowing (i.e., when pressed onto a vertical surface it will flow under its own weight).

The terminal group Y can be any unsubstituted or inertly substituted noncrosslinking organic group or a mixture thereof with a minor amount of a (vinyl-aryl)alkyl group.

Preferably, the terminal group Y is a Cl-C18 alkyl group, or an (aryl)alkyl group. More preferably, the terminal group is a benzyl group. The terminal group Y may contain diverse inert substituent groups which do not interfere with the preparation of the elastomer. The terminal group Y may comprise a minor portion of a (vinylaryl)alkyl group. Such (vinylaryl)-alkyl groups generally comprise less than 10, prefer-- ably less than 5, more preferred less than 2 percent of ~ 25 the terminal groups in the noncuràble polysulfide ; polymer.

Except for the propor~ion of (vinylaryl)alkyl terminal groups in these preferred noncurable polysul-fide polymers; these noncurable polysulfide polymers generally and preferably contain the same constituent structural groups as described in the for~going discus-sion of the pxeferred curable polysulfide polymers.

31,939B-F -10-131 67G, - 11 ~ 64693-3743D

These noncurable polysulfide polymers are also advantageously prepared according to the methods described in the aforementioned United States Patent No. 4,438,259 modified so that the metal polysulfide is reacted with an inertly substituted monofunctional organic compound which contains a negatively charged functionality which will split off upon reacting with the metal polysulfide in the reaction mixture. By inertly substituted is meant that the monofunctional organic compound contains no substituent groups which chemically reacts under the conditions of the polymerization reaction. Exemplary inert substituents include, for example, alkyl groups. A wide variety of monofunctional organic compounds are usefully employed herein. The monofunctional organic compound may be, for example, an alkyl halide or sulfate, particularly a C2-C18 alkyl chloride or bromide. Halogenated or sulfated cycloalkyl compounds are useful, as well as (aryl)alkyl halides, sulfates and the like. Of the foregoing, (aryl)alkyl halides are preferred.
The monofunctional organic compound is preferably one which is not capable of engaging in a curing reaction, or a mix-ture of such a noncross-linking compound with a (vinylaryl)alkyl halide or other compound which reacts with the metal polysulfide to form a terminal (vinylaryl)alkyl group. When such a mixture of monofunctional organic compounds is employed, the proportion of such mixture employed is preferably such that the resulting polysulfide polymer is incapable of curing to a material which does not cold flow. In other words, it is preferred to have a polysulfide which is incapable of curing to form a highly cross-linked material. Of -12- ~
1 3 1 67 G ~`;, course, in evaluating the curing behavior of the poly-sulfide, such behavior refers to the curing charac-teristics of neat polysulfide elastomers. The inclu-sion of diverse additives may affect the mechanical properties o~ the p~lysulfide material such that even those containing very small amounts of (vinylarly)alkyl terminal groups do not cold flow.

Most preferably, the monofunctional organic compound is an unsubstituted or inertly substituted benzyl halide, or a mixture thereof with an unsub-stituted or inertly substituted vinylbenzyl halide.

Noncurable polysulfide polymers are formed by introducing, in addition to the monofunctional organic compound, an organic compound having a plurality of negatively charged functionalities attached to an aliphatic or cycloaliphatie carbon atoms, which fune-tionalities will split off upon reaeting with the metal sulfide in the reaetion mixture. As used herein, the term "negatively eharged funetionality" means a func-tional group which will split off on reacting with themetal polysulfide to ~orm an anionic species in solution.
The functional group is not necessarily ionically bonded to the aliphatic hydrocarbon or (vinylaryl)alkyl compound, and, in faet, is generally;~v~lently bonded thereto. The polymerization of polysulfides and poly-functional organc compounds are well known in the art and is first described in U.S. Patent No. 1,890,191 to Patrick. Suitable polyfunctional compounds include alkyl dihalides, disulfates, diacetates and the like which will polymerize with the polysulfide and the monofunctional organic compound to form a linear polymer represented by the formula:

31,939B-F -12-1 31 67~3 Y~(SnRa)mSnY

wherein m is a positive integer, n and Y are as defined hereinbefore and Ra represents an organic diradical, with each valence residing on a carbon atom, which is the residue of the difunctional hydro-carbon after the splitting off of the negatively charged functionalities. In general, chlorides are preferred as the negatively charged functional group due to the facility of their reaction with metal polysulfides, their relatively low cost and high availability. The Ra group, and correspondingly, the polyfunctional organic compound, may further contain substituents which are inert under the conditions of the polymer-ization reaction and may further incorporate linkages such as ether, sulfide, al~ene or arylene into the chain. In general, those polyfunctional monomers previously known to react with metal polysulfides to form polymers therewith are also suitably employed in this invention. Preferred polyfunctional monomers include dichloroethane, 1,2,3-trichloropropane, bis--2-chloroethyl formal, bis-4-chlorobutyl ether, bis--4-chlorobutyl formal and 1,3-dichloro-2-propanol.
Other polyfunctional monomers, which are illustrative of the wide scope of monomers suitable employed herein include, for example,~bis(4~c~1Oromethyl)phenyl ether, bis(4-chloroacetyl)phenyl ether, 2,5'-di(chloromethyl)-1,4-dioxane and diethylene glycol bis(chloroacetate), propylene dichloride, and 1,4-diehloro-2-butene.

Trifunctional, tetrafunctional and penta-functional organic compounds, such as 1,2,3-trichloro-propane and the like, may be employed in conjunction with di~unctional hydrocarbons and will polymerize .

31,939B-F -13-, -14- l 3l ~7 G'J

with the polysulfide and the (vinylaryl)alkyl compound to form a branched polymer as represented by the general structure:

[ n ~ n nR)l Sn~Y]p wherein 1 and m are positive integers, n and Y are as defined hereinbefore, each R is independently a polyvalent organic polyradical with each valence residing on a carbon atom, and p is zero or a posi-tive number which is the difference between thevalence of R and ~wo. It is noted that each R is the residue formed by the splitting off of the negatively charged functionalities from the respec-tive difunctional and polyfunctional hydrocarbons.

lS The amount and degree of branching of the uncurable polysulfide polymer is selectively determined by the choice and relative proportion of the organic monomers employed in the reaction.
By polymerizing polysulfides with a mixture of difunctional and tri-, tetra- or pentafunctional monomers, a branched chain mayibe formed as desired.
In general, suitably branched polysulfide polymers are produced by employing from 90 to 99.5 weight percent of a difunctional monomer and from 10 to 0.5 weight percent of a monomer having at least three functionalities, said percentages being based on the total weight of all the polyfunctional monomers employed in the reaction. If higher modulus and lower cold flow in the cured polymer are desired, from 2 to 10 weight percent, preferably from 3 to 5 weight percent, of a monomer having at least three 31,939B-F -14-, -15- ~ 3~ 67 G~

functionalities is employed, said percentages being based on the total weight of all the polyfunctional monomers employed in the react:ion. If the polymer is to be employed as a sealant, from 0.5 to 4 weight percent of a monomer having at least 3 function-alities is beneficially employed.

The polyfunctional monomer is chosen such that the uncurable polysulfide polymer produced there-from has the desired physical properties. Many of the beneficial properties of polysulfide polymers, such as resistance to oxygen permeation, water, unltra-violet light and solvents are generally attributable to the polysulfide segments of the polymer. When the sulfur link is three or more, the sulfur linkages also impart flexibility to the polymer. By contact, properties such as high elongation, flexibility, and increased solubility may be selectively imparted to the polymers primarily by the organic segments.
Thus, the properties of the uncurable polysulfide poly-mers can be ~electively determined by the choiceof organic monomers and the rank of the polysulfide segments. For example, a high sulfur polymer can be produced by employing low molecular weight organic compounds, such as bis-2-chloromethyl formal, 1,2,3-trichloropropane or ethylene dichloride. Similarly, polysulfides of varying rank may be employed to selectively vary the carbon to ~ulfur ratio in the polymeric chain.

The reaction i6 suitably carried out by heating the aqueous polysulfide solution from 3Q 25 to 90C, preferably from 50 to 80C, and adding the organic monomer and the monofunctional organic compound over a period of 5 minutes to 2 hours.

31,939B-F -15-1 3 1 67 l'j ?, The mixture is then heated at 25 to 90C, pre~erably from 50 to 80C, for 1 to 3 hours to form the desired organic-terminated polysulfide.
The noncurable polysulfide polymers have a theoretical molecular weight, as calculated from the relative proportion of the reactants employed in their preparation, of at least 490, preferably from 3,000 to 200,000, more preferably from 3,000 to 25,000.
The unsaturated organic elastomer contains a measurable proportion of ethylenic unsaturation. The saturated organic elastomer contains a saturated chain of the polymethylene type.
The term "elastomer" is employed herein to refer to high molecular weight polymers having the ability to be stretched to at least twice their normal length and to retract rapidly to approximately their orginal length when released. As used herein, the term elastomer includes both natural rubber and synthetic rubbers. Such elastomer may be a thermosettable polymer, but most typically, is thermoplastic.
The unsaturated organic elastomer contains a measurable amount of ethylenic unsaturation. By "ethylenic unsaturation" it is meant the presence of a nonconjugated carbon-carbon double bond.
Preferably, this carbon-carbon double bond is reactive (i.e., will readily engage in reactions common to compounds containing such unsaturation). The ethylenic unsaturation may reside along the polymer backbone, as in the case of polybutadiene elastomers, or may reside in a pendant group or a side chain such as ethylene/-propylene/non-conjugated diene terpolymer.

1 31 ~7G'~
- 17 - 6~693-3743D
The unsaturated organic elastomer contains a measurable proportion of said ethylenic unsaturation. While not intending to limit the invention of the parent application to any theory, it is believed that the blend of the polysulfide polymer and the unsaturated organic elastomer has improved compatibility because of the vulcanization of the organic elastomer with the polysulfide polymer. However, the decision to use an unsaturated or saturated organic elastomer depends primarily on the end use of the resin and the properties sought for that resin.
Generally, the unsaturated organic elastomer advantage-ously contains at least one carbon-carbon double bond per 50 repeating units (mers) of the polymer. Preferably, there is at least one carbon-carbon double bond per 10 mers, more preferably at least one carbon-carbon double bond per 5 mers of the unsaturat-ed organic polymer. Polymers such as polyisoprene, which contain essentially one carbon-carbon double bond per repeating unit are also suitably employed herein.
The unsaturated organic elastomer may be a homopolymer of a monomer which polymerizes to a polymer containing ethylenic unsaturation. Alternatively, it may be a random copolymer of such a monomer with one or more other copolymerizable monomers which may or may not give rise to sites of ethylenic unsaturation in the polymer. In addition, the unsaturated organic elastomer may be a block copolymer having two or more discrete segments, one or more of which contain ethylenic unsaturation. Similarly, graft copolymers in which at least one of the backbone or grafted chains contain ethylenic unsaturation may be employed herein.

131~7Gij ~

O~e suitable class of unsaturated organic elastomers includes the homopolymers and interpolym~rs of conjugated dienes. Examples of such homopolymers include poly(butadiene), poly(isoprene), poly(1,4--hexadiene) and the like. Said conjugated dienes may optionally contain inert substituent groups such as alkyl groups or halogen atoms. An example of a halo-genated conjugated diene is chloroprene. Polymers of such conjugated dienes contain residual double bonds on the polymer backbone, approximately one double bond per repeating unit of the polymer.

Also suitable are random copolymers of con-jugated dienes with at least one other copolymerizable monomer, which copolymers are elastomers containing ethylenic unsaturation. Said other copolymerizable monomers include, for example, alkenes such a~ ethylene, propene, n-butylene, isobutylene and the like, vinyl aromatics such as styrene, vinyltoluene, t-butyl-styrene, vinylnapht`halene and the like, acrylic esters such as alkyl acrylates and alkyl methacrylates; halo-genated alkenes such as vinyl chloride, vinylidene chloride, vinyl bromide and vinylidene bromide; acrylo-nitrile and acrylamide. Of particular interest are the so-called nitrile rubbers which are random copolymers of acrylonitrile and butadiene; styrene-butadiene rubbers; the so-called butyl rubbers which are copoly-mers of isobutylene~and isoprene; and the halogenated analogs thereof.

In addition, homopolymers and copolymers of bicyclic dienes such as dicyclopentadiene, or norborn-ene. Terpolymers of ethylene and/or propylene with bicyclic dienes are also suitable.

31,939B-F -18-131 h7G, The so-called polypenteneamers (i.e., polymers of cyclo-pentene and homologs thereof~ are also useful.
In addition to the aforementioned homopolymers and copolymers, elastomeric block copolymers containing at least one segment having residual ethylenic unsaturation are suitably employ-ed. Compatibility of the block copolymer and the polysuifide polymer is readily tested by mixing small amounts of the block co-polymer and the polysulfide in the desired proportions according to the methods described hereinafter and observing whether phase separation or other indicia of incompatibility occur. Especially suitable are block copolymers of styrene and a conjugated diene, such as styrene/isoprene block copolymers or styrene/isoprene triblock copolymers.
Similarly, graft copolymers wherein the polymer back-bone and/or the graft segment contains ethylenic unsaturation can be employed. As with the block copolymers, the graft copolymers suitably contain sufficient of the unsaturated segment to enable the polymer to be blended with the polysulfide elastomer.
The saturated organic elastomers contain a saturated chain of the polymethylene type. Saturated organic elastomers are blended with at least one organic-terminated polysulfide polymer to generally obtain a composition which exhibits improved physical properties similar to those exhibited when the polysulfide polymers are blended with unsaturated organic elastomers. The saturated organic elastomer may be chlorinated polyethylene or polyiso-butylene.

1 31 67'i3 Another aspect involves the blending of non-elastomeric polymers with at least one organic terminated polysulfide polymer.
These blends exhibit improved physical properties including improved resilience, recovery compression set and lower modulus while maintaining general polysulfide properties. The non-elastomeric polymer may be polystyrene, low density polyethylene, high density polyethylene, linear low density polyethylene, or polychloromethyl oxirane. A suitable commercial polystyrene resin is sold under the trademark STYRON by The Dow Chemical Company.
The non-elastomeric polymer may also be copolymers of: an alkyl arcylate and acrylonitrile; ethylene and vinyl acetate; ethylene and propylene; ethylene oxide and chloromethyl oxirane; and vinyl chloride and vinylidene chloride.
Another aspect involves the blending of any combination of the previously discussed organic polymers to obtain an organic polymer blend to blend with the polysulfide polymer. A preferred embodiment is the blending of a saturated organic elastomer, an unsaturated elastomer and at least one organic-terminated poly-sulfide polymer. Examples of this blending method are shown in Examples 7A, 7B and 8. Such blends exhibit improved physical properties similar to those exhibited when polysulfide polymers are blended with unsaturated or saturated organic elastomers.
All the foregoing unsaturated and saturated organic elastomers can be prepared using addition polymerization techniques well known in the art. For a general overview on the preparation of organic elastomers see the Kirk-Othmer Encyclopedia of Chemical 1 31 67'iJ

Technology, 3rd Edition, Vol. 8, pages 446-640.
A suitable commercial polyisoprene is sold under the name NatsynTM 2205 by The Goodyear Chemical Company. An exemplary polyisobutylene is sold under the brand name Vistanex M by Exxon Corporation. Suitable commercially available nitrile rubbers include those sold under the brand names HycarTM 1411 and Hycar M
1422, available from B. F. Goodrich Company. A suitable styrene/
butadiene block copolymer is sold under the name SolpreneTM 1205 by Phillips Petroleum Company. Kraton M D1102, a triblock styrene/
butadiene polymer having a melt index of 6 is also usefully employed. This polymer is available from Shell Oil Co. Also use-ful is KratonTM D1107 triblock styrene/isoprene polymer having a melt index of 9. This material is also available from Shell Oil Co. A brominated butyl rubber and a chlorinated butyl rubber are commercially available from Exxon Corporation.
The organic-terminated polysulfide polymer and the organic polymer are thoroughly mixed to form the blend. The blending is advantageously, but not necessarily, performed in the absence of an organic solvent. The blending can be accomplished at room temperature or at any elevated temperature at which the organic-terminated polysulfide polymer and/or organic polymer are softened. Preferably, the blending is performed at 20-120C.
Blending is generally continued until the blend appears homo-geneous. When a curable organic-terminated polysulfide polymer is employed, blending is preferably conducted while the polysul-fide polymer is in the uncured state. The energy expended in the 13167~','i blending process generally promotes some, if not complete, curing of the curable organic-terminated polysulfide polymer. Such curing is especially present if the blending is conducted at elevated temperatures such as 50-120C.
Generally, 0 to 100, preferably 5 to 30 parts of the rubber are employed per 100 parts polysulfide polymer.
Although it is not intended to limit the invention of the parent application to any theory, it is believed that the energy expended in blending the polymer not only promotes physical intermixing of the polymers but also initiates a chemical reaction between the organic-terminated polysulfide polymer and the organic polymer. It is theorized that the energy of mixing causes cleavage of some of the sulfur-sulfur bonds in the polysulfide, forming free radicals and also produces free radicals in the organic polymer. These free radicals then react with sites of unsaturation on the unsaturated organic elastomer, forming cross-links between the polysulfide elastomer and the unsaturated organic elastomer. In the reaction with saturated organic elastomer, crosslinks are formed due to free radical formation brought about by physical mastication. This result occurs even though there is no chemically reactive site on the saturated organic elastomer.
It is believed that the formation of said crosslinkages in the blend is responsible for the unexpected compatibility of the organic-terminated polysulfide polymer and the organic polymer.
The blends exhibit beneficial and unexpected properties.
The organic-terminated polysulfide polymer plasticizes the organic - 23 - 1 31 67 ~ ) 64693-3743D
polymer, especially in those embodiments wherein the organic poly-mer is the major component of the blend. In addition, the organic-terminated polysulfide polymer can act as a vulcanizer for the unsaturated organic elastomer (i.e. the polysulfide polymer crosslinks the unsaturated organic elastomer). Thus, the organic-terminated polysulfide polymer can be employed in place of con-ventional plasticizers and vulcanizers for the unsaturated organic elastomer. However, the saturated organic elastomer is not vulcanizable. Block and graft polymer formation and crosslinking is still observed with the saturated organic polymer blends due to free radical formation. Additionally, the organic-terminated polysulfide polymer is vulcanizable and, therefore, curable through the vinyl groups by using elemental sulphur in the blend or through other reactive sites. The organic-terminated polysul-fide polymer further imparts the desirable characteristics of improved adhesion and UV, ozone, solvent and water resistance to the blends, as compared to the organic polymer alone.
The blends also exhibit improved mechanical properties as compared to the polysulfide polymer alone. In general, the blends, even those in which the organic polymer is a minor com-ponent , exhibit higher tensile strength and more elastomeric behavior than do the polysulfide polymers.
In addition, the blends are more resilient, have im-proved compression set and/or exhibit lower notch sensitivity than the corresponding polysulfide polymer alone. In some instances the blend is also more adhesive and resistant to solvents, water ~ 24 - 64693-3743D

and the like than the corresponding organic polymer alone.
In addition to the polysulfide polymer and the organic polymer, the blends may optionally contain various additives such as fillers, pigments, reinforcing agents, curing agents, plasticizers, release agents, dyes, inhibitors and the like for their art recognized function. secause the polysulfide plasti-cizes and vulcanizes the unsaturated organic elastomer, additional plasticizer and vulcanizer are generally not necessary in this blend.
Also the curable or noncurable organic-terminated polysulfide polymer may be employed as the sealant but is prefer-ably employed with pigments, fillers, synthetic rubbers and/or curing agents in order to import specific desirable properties to the sealant.
Inorganic and organic pigments and fillers are also advantageously employed in these blends and with the neat polysul-fide polymers. Exemplary such pigments and fillers include carbon black, titanium dioxide, calcium carbonate, colored pigments like cadmium sulfide, clay, asbestos, wood flour, zinc oxide and the like. While the particular amount of said pigment or filler employed varies somewhat depending on the particular properties desired as well as the molecular weight and composition of the polysulfide, in general such pigment or filler from 0 to 95, preferably from 10 to 60 percent by weight of the filled blend.
When the neat polysulfide polymer is employed as a sealant from 0 to 200 or more, preferably from 10 + 50 parts by weight filler or pigment are employed per 100 parts polysulfide polymer.

1 31 67';, In general, increased levels of filler or pigment increase the tensile strength of the cured sealant. In addition, the low molecular weight polysulfide polymers or polymers with relativelylow amounts of (vinylaryl)a:Lkyl terminal groups will typically not cure or only cure to sealants having lower strength or resilience. Accordingly, the amount of pigment or filler employed can vary with the particular polysulfide to obtain the desired properties.
The blends are useful in preparing tough solvent-resistant articles such as gaskets, hoses, tubing, membranes, barrier films, weather resistant films, adhesive tapes, hot melt adhesive, hot melt sealant, and the like. The utility of the blends will/ of course/ depend somewhat on the particular composi-tion thereof. For example/ blends containing relatively small amounts of polysulfide polymer may be employed in applications for which the organic polymer alone is conventionally employed. In such applications/ the blend will typicalLy exhibit improved adhesion as well as greater solvent/ water and ultraviolet light resistance. Similarly/ the blend/ having a high proportion of polysulfide polymer is advantageously employed as an adhesive/
sealant or in like compositions for which conventional polysulfide polymers are employed.
In addition to the foregoing/ accelerators/ free radical initiators/ surfactants, dyes and other additives may be employed in the sealant for their art recognized function.

1 31 67'?, ~ hile the sealant may be applied to the joint or crack while cold, it is sometimes preferred to use heat in order to soften the sealant, decrease the viscosity and/or to increase the binding of the sealant to the asphalt or concrete. When heat is used to apply the sealant, the heat also serves to cure those sealants employing a curable polysulfide elastomer. The proper-ties of the sealant can be varied somewhat by the choice of additives and flllers in order to obtain the desired character-istics of melting or softening point, tackiness, mechanical properties, curing and the like. Increased tackiness, lower ten-sile strength, reduced resilience and lower softening point are generally exhibited in sealants containing a relatively high proportion of the polysulfide elastomer. Highly filled materials generally exhibit relatively higher softening points and are usually tougher and more resilient than unfilled sealants. The sealants which contain organic elastomers are highly resilient.
By the choice of the type and proportion of the components employed in the sealants, the sealant can often be adapted to meet the particular requirements of the application for which it will be employed.
A major advantage of the sealant is the ease with which it is applied. These sealants may be applied simply by placing a quantity of the cold sealant in contact with the surface of the crack or joint to be sealed. Preferably, the surfaces of the cracks are cleaned to remove loose particles, water and the like - 27 ~ 67 G I3 64693-3743D

before applying the sealant. When applied to the crack o~ joint cold, adhesion of the sealant to the surface of the crack or joint develops upon the infusion of small amounts of energy.
Often the adhesion develops at room temperature with the addition of a small amount of mechanical energy. For example, a crack in a concrete highway is advantageously sealed by filling the crack with the cold sealant of the invention. The subsequent heating and pressure action of traffic on the highway can provide the energy needed to completely adhere the sealant to the con-crete substrate.
Improved adhesion oE the sealant to the substrate immediately upon application is generally effected by heating the sealant slightly before or after applying. Heating also serves to soften the sealant and reduce its viscosity. A curable poly-sulfide elastomer will cure (i.e., become cross-linked upon heating). Because the sealants can be heated for application, they can be used with equipment conventionally used for applying hot sealants to concrete or asphalt structures, such as a hot melt gun, pumping equipment and the like.
A further advantage to the method and sealants is that the structure sealed therewith is ready for use almost im-mediately after the application of the sealant. Upon application, these sealants do not require a period of time for setting, curing or cooling before use. This advantage is of significant impor-tance in highway repair, because the period of time during which the highway must be closed for repairs is significantly reduced.

13167'3 - 2~ - 64693-3743D

The method encompasses the sealing of joints or cracks in concrete and/or asphalt structures. By "joints or cracks in concrete or asphalt structures" is meant any discontinuity or gap between a concrete or asphalt member of such structure and any adjacent member thereof. Said adjacent member may be concrete or asphalt or any other solid material to which the polysulfide adheres, including wood, plastic, rubber, metal, glass or other surface. Preferably, the adjacent surface is also asphalt or concrete. The method is particularly suitable for sealing joints or cracks in concrete structures such as roads, highways, parking lots, driveways, sidewalks, masonry and the like. Of special interest are joints between concrete road beds and adjacent asphalt shoulders.
The following examples are provided to illustrate the inventions of both the parent and divisional applications but are not intended to limit the scope thereof. All parts and percent-ages are by weight unless otherwise indicated.
Example 1 The polysulfide polymer employed in this example and Examples 2-6 and 9-12 was prepared by dissolving 27.7 weight percent (based on total weight of reactants) disodium sulfide in water, adding 3~.2 weight percent precipitated sulfur and heating at reflux for 1 hour to produce sodium polysulfide. Emulsifiers were then added to the aqueous phase, and 2.5 weight percent vinylbenzyl chloride, 2 weight percent benzyl chloride, 31.7 weight percent ethylene i -29- 13167G3 dichloride, and 1.9 weight percent 1,2,3-trichloro-propane were added over a 1 hour period. The mixture was then heated to 70C for 1 more hour. The emulsion was broken and a viscous liquid was recovered. This sample contains 78 percent sulfur and has a theoretical molecular weight of 6,000.

A 30 part portion of the polyisoprene (Natsyn 2205 sold by the Goodyear Chemical Company) was masti-cated at 30C in a Brabender Mixer until softened. To the softened polyisoprene was then added 100 parts of the polysulfide polymer. The~polyisoprene and the polysulfide elastomer were masticated in the Brabender mixer until the blend assumed a uniform appearance.
The resulting blend was then formed into a 1/8 inch (0.3 cm) thick film. The film is then cut into 4 inch by 4 inch by 1/8 inch (10 cm by 10 cm by 0.3 cm) tensile bars for evaluation. The tensile strength of the film is evaluated on an Instron tensile tester. A maximum tensile strength of 13.2 lbs./in2 (91 kPa) is exhibited.
By comparision, a similar film prepared from the poly-sulfide elastomer alone exhibits a maximum tensile strength of only 7.7 lbæ/in2 (53 kPa).

Another blend was prepared in like manner from 100 parts of polysulfide polymer, 30 parts poly-isoprene and 30 parts carbon black. A film of thèblended material was tested on the Instron and found to have a maximum tensile strength of 42.9 lbs/in2 (296 kPa).

Exam~le 2 A blend was prepared from 100 parts by weight polysulfide polymer and 30 parts by weight of a triblock 31,939B-F -29-~30- l 31 ~7~

styrene/butadiene polymer containing 28 percent styrene and 72 percent butadiene, sold commercially under the brand name Kraton D1102 by Shell Chemical Corporation.
In forming the blend, the rubber was added to the Brabender Mixer at 125C and softened, at which time the polysulfide polymer was added and mixed with the rubber until the blend appeared homog-eneous. This blend was tested on the Instron as described in Example 1 and found to exhibit à maximum tensile strength of 47.8 lbs/in2 (329.5 kPa). A film of this blend was stretched to 200 percent elongation and released. Upon release, the film retracted rapidly and recovered 94 percent of said elongation. Another film was elongated to 800 percent of its original length and released. Upon release, the film retracted by 85 percent.

ExamPle-3 The procedure of Example 2 was repeated, this time employing a triblock styrene/isoprene triblock polymer containing 14 percent styrene and 86 percent isoprene, commercially available under the brand name Kraton Dl107 from the Shell Chemical Corporation. Upon testing on the Instron, this blend exhibited a maximum tensile strength of 39.1 lbs/in2 (269.5 kPa). After elongation to 200 percent of its original length, a film retracted by 94 percent. Another film, after elongation to 800 percent of its original length, . . .
retracted by 64 percent.

Example 4 A blend was prepared according to the method of Example 2, this time employing a linear diblock styrene butadiene polymer containiny 25 percent styrene, 75 percent butadiene, commercially available under 31,939B-F -30-J -31- 1 31 67'~

brand name Solprene 1205 from~the Phillip~ Petroleum Company. Upon testing on the Instron, this material exhibited a maximum tensile strength of 20 lbs/in2 (137.9 ~Pa).

Example 5 k blend was prepared according to the pro-cedure described in Example 2, this time employing a nitrile rubber containing 40 percent acrylonitrile, sold commercially under the brand name Hycar 1411 by the B. F. Goodrich Company. Upon testing on the Instron, this material exhibited a maximum tensile strength of 36.4 lbs/in (250.9 kPa). A film of this material retracted by 88 percent after elongation to 400 percent of its original length. Another film of this material retracted by 40 percent after elongation to 800 percent of its original length.

Example 6 A blend was formed according to the process of Example 1, this time employing a nitrile rubber containing 33 percent acrylonitrile, commercially available under the brand name Hycar 1422 from B. F.
Goodrich. Films from this material exhibited a maximum tensile strength of 28.8 lbs/in2 (198.5 Kpa). A film prepared from this blend recovered by 55 percent after elongation to 400 times its original length and by 10 percent after elongation.to.800 percent of its original length.

Example 7 Using the general procedure described in Example 1, a polysulfide polymer was prepared from the following reagents:

31,939B-F -31--32- 1 31 6iG3 Na2S (as nonahydrate) 27.8 weight percent Sulfur34.3 weight percent Vinylbenzyl chloxide 2~2 weight percent Benzyl chloride1.9 weight percent Ethylene chloride32.8 weight percent - The resulti~g polysulfide polymer is linear, curable and has a theoretical number average molecular weight of 4,000.

The polysulfide was blended into Sample Nos.
7a, 7b and 7c according to the general procedure des-cribed in Example 2. The components of the blend are as indicated in the following table.

. Sam~le No. (Parts) Component 7A 7B iC
15 Polysulfide Elastomer 100 100 100 Kraton B1107 5 lO 10 Vistanex L-801 5 5 --Carbon Black N762 , 30 30 15 Carbon Black N234 -- -- 15 20 ZnO 2.5 2.5 2.5 Peak Tensile (psi) -- 14 66.3 [kPa] [96.5] [4S7]
Tensile @ 800~ elongation -- 3.6 20.8 25 lPolyisobutylene, available from Exxon Chemicals Sample No. 7A passed two cycles of the exten-sion test described in ASTM D-1191-64. After two cycles of the test, the evaluation.was terminated without failure of the sealant.

31,939B-F -32-~33~ 1 31 67 Example 8 Using the yeneral procedure described in Example 1, a polysulfide elastomer was prepared from the following reagents:

Na2S (as nonahydrate) 28.3 weight percent Sulfur34.8 weight percent Vinylbenzyl chloride0.9 weight percent Benzyl chloride0.7 weight percent Ethylene dichloride35.3 weight percent Using the general procedure described in Example 1, 100 parts of this polysulfide elastomer were blended with 5 parts Vistanex L-80, 5 parts Kraton D1107, 30 parts carbon black and 2.5 parts zinc oxide.
The blend exhibits a peak tensile of 33.9 psi ~233.7 kPa) and a tensile at 800 percent elongation of 7.0 psi (48 kPa)-.

Example_9 A blend was prepared according to the pro-cedure described in Example 1, this time employing 30 parts of polyisobutylene, commercially available under the brand name Vistanex L-80 from Exxon Chemicals. A
film from this blend exhibited a tensile of 16.3 lbs/in2 (112.4 kPa) at 800 percent elongation and a yield point of 100 percent elongation of 10.2 lbs/in2 (70.3 kPa).
.
Example 10 ~ blend was prepared according to the pro-cedure described in Example 1, this time employing 30 parts polystyrene ~the polystyrene used is sold by The Dow Chemical Company under the trademark STYRON 60-75).

31,939B-F -33-J ~34~ l 3167u~ ~

A film from this ble~d exhibited a peak tensile of 95.5 lbs/inZ (658~5 kPa) and a tensile of 28.7 lbs/in2 (197.7 kPa) at 800 percent elongation.

Example 11 S : A blend was prepared according to the pro-cedure described in Example 1, this time employing 15 parts high density polyethylene. A film from this blend exhibited a peak tensile of 25.1'lbs/inZ (173 kPa) at 800 percent elongation.

Exam~le 12 A blend was prepared according to the proce-dure described in ~xampl~ 1, this time employing 30 parts polypropylene, commercially available under the brand name Pro-~ax~ 6323 from ~imont Corporation. Films from this blend exhibited a peak tensile of 31.2 lbs/in2 (215 kPa) and a tensile of 25.9 Ibs/in2 (178.6 kPa) at 800 percent elongation.

Example 13 Polysulfide Polymer Sample No. 1 was prepared by dissolving 27.7 weight percent disodium sulfide (based on total weight of all reactants) in water, adding 34.2 weight percent precipitated sulfur and heating at reflux for 1 hour to produce the sodium polysulfide. Emulsifiers were then added to the aqueous phase and 2.5 parts vinylbenzyl chloride, 2 ~arts benzyl chloride, 31.7 parts ethylene dichloride, and 1.9 parts 1,2,3-trichloropropane were added over a 1 hour period. The mixture was then heated to 70C for another hour. The emulsion was broke~ and a viscous liquid was recovered. ~his sample contains 78 percent sulfur and has a theoretical molecular weight of 6,000.

31,939B-F -34-_, -35~ 1 31 67'3 Polysulfide Polymer Sample No. 2 was pre-pared in like manner using 28.3 parts disodium sulfide, 34.8 parts sulfur, 0.9 part vinylbenzyl chloride, 0.7 part benzyl chloride and 35.3 parts ethylene dichloride.
The product contains 80.6 percent sulfur and has a theoretical molecular weight of 10,000.

Polysulfide Polymer Sample No. 3 was prepared in like manner using 27.8 parts Na2S (as nonahydrate), 34.3 parts sulfur, 2.2 parts vinylbenzylchloride, 1.9 parts benzyl chloride and 33.8 parts ethylene dichloride.
The resulting polysulfide is linear and has a theoret-ical molecular weight of 4,000.

Sealant Formulation Nos. 1-6 were prepared from the components listed in Table I following.

31, 939B-F -35-~ -36- ~
13167~

TABLE I
Formulation Sample No._ Sealant 1 2 3 4 5 6 Polysulfide Elastomer No. 1 100 100 -- -- 100 --Polysulfide Elastomer No. 2 -- -- 100 100 -- --Polysulfide Elastomer No. 3 -- -- -- -- -- 100 Kraton D11071 5 10 10 10 -- 5 CaCO~ -- 30 30 30 -- --Carbon Black4 Carbon Black Carbon Black ZnO 5 5 5 -- -- 2.5 Altox2 1 1 1 -- -- --Morfax3 -- -- -- -- 5 --.
Stearic Acid -- 1 1 -- -- --t-Butyl Perbenzoate -- -- -- -- 1 --Exxon Poly-isobutylene -- -- -- -- -- 5 IA triblock styrene/isoprene polymer containing 14% styrene, having a melt index of 9, available from Shell Chemical Co.
2Benzothiazyl disulfide, sold by R. T. Vanderbilt Co.
3A commercial vulcanizing agent available from R. T. Vanderbilt Co.
4Commercially available, sold by Cabot Corporation.

Blending of components was done on a Brabender Mixer. The rubber (in Formulation Nos. 1-4 and 6) was masticated on the Brabender before adding the polysul-fide and other components. After the components were 31,939B-F -36-~ _37_ 13167G, blended, mastication was continued until the blend was uniform in appearance.

Molded 4 inch by 4 inch by 1/8 inch (10 cm x 10 cm x 0.3 cm) films were formed from each of the Seal-ant Formulation Nos. 1-~ and tested on the Instron Ten-sile Tester for yield tensile strength, e.ongation and tensile and maximum elongation. Results are as reported in Table II following:

TABLE II
Sealant Formulation No.
1 2 3 4 ~5 6 Yield Tensile, psi ND 53.2 26.829.g 33.1 6 Elongation at Break, %1 800 800 50800 800 33.9 Tensile at Maxium Elon-gation, pSi239.1 41.2 ND 23.7 7.5 7.0 (269.6 kPa) (284 kPa) (163.4 kPa) (51.7 kPa) (48 kPa) ND = Not determined All tests end at 800% elongation if the film is not broken.
2 s 2Determine at 800% elongation.

Sealant Formulation No. 5 was used to seal cracks in concrete and asphalt pavement. The sealant was formed into a long "rope" which rope was placed into the cracks and contacted with the edges thereof.
Adhesion to the concrete and asphalt was excellent and the cracks were completely sealed. One year after application, the seals remain intact and adherent to the substrate.

Sealant Formulation No. 5 was also used to bond together two 1 inch x 2 inch x 4 inch (2.5 cm x 5 cm x 10 c~:) concrete blocks. Two such blocks were 31,939B-F -37-` ' f -38- 13167G~'`

bonded together by covering one 1 inch x 2 inch (2.5 cm x 5 cm~ face of the block with the sealant formu-lation, at 50C, and allowing the sealants to cool.
After cooling, excellent adhesion of the sealant to the block was seen. Multiple 180 twists and bends of the blocks relative-to each other failed to break the bond.

Sealant Formulation`Sample Nos. 1-4 ~and 6 were evaluated in like manner and also exhibit excel-lent adhesion to concrete and asphalt.

Example 14 A polysulfide polymer was prepared according to the general procedure described in Example 13, using 27.8 parts Na2S, 34.3 parts sulfur, 0.5 parts vinyl-- 15 benzylchloride, 3.7 parts benzyl chloride, 33.2 parts ethylene dichloride and 0.5 parts 1,2,3 trichloropropane.

100 parts of this elastomer were blended with 20 parts Exxon butyl rubber 065, 15 parts carbon black and 2.5 parts zinc oxide, using a Brabender as described in Example 13.

The resulting sealant was capable of being extruded at 50~C at 60 psi (414 kPa) pressure. Accord-ingly, the sealant can be used in hot melt guns and similar apparatus.
.
Exam~le~ 15 A 100 part portion of polysulfide elastomer Sample No. 2 (Example 13~ was blended with 10 parts Exxon butyl rubber 065, 20 parts carbon black and 2.5 parts zinc oxide. The resulting sealant was firm and 31,939B-F -38-~ -39- 1 3 1 6 7 ~ ~3 rigid when formed into rods. This sealant was also capable of being extruded, as in a hot melt gun, for application. Alternatively, however, this sealant can be applied simply by placing a quantity thereof into contact with the edges of the crack or joint to be sealed.

31,939B-F -39-

Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A method of sealing cracks or joints in concrete or asphalt structures by applying a sealant to said cracks or joints characterized in that at least one organic-terminated polysulfide polymer represented by the plural formulae I and II
wherein n is a number from 2 to 8, 1 is zero or a positive integer, m is a positive integer, each R is independently an unsubstituted or inertly substituted organic polyradical with the radicals residing in carbon atoms, p is zero or a positive number which is the difference between the number of valence of R and 2, and each Y and Z is independently chosen from the class consisting of (vinylaryl)alkyl and other inertly substituted noncross-linking monoradicals provided that at least a portion of Z is (vinylaryl) alkyl, is employed as the sealant in an amount sufficient to seal said cracks or joints.
2. The method of Claim 1, characterized in that said sealant is melted or softened prior to application to said cracks or joints.
3. The method of Claim 1, characterized in that said seal ant includes an inorganic pigment or filler.