CA1116344A - Polymers containing 2,5-oxolanylene segments - Google Patents

Abstract

ABSTRACT
Polymers containing recurring 2,5-oxolanylene units wherein at least 60 percent of the units are joined directly to one another so as to provide segments consisting of at least 6 of said units.

Description

3~

`~ -Thls inventlon relates to polymers contalnlng

2,5-oxolanylene segments. More partlcularly it relates to polymers contalnlng recurrlng 2,5-oxolanylene tor oxolane) unlts of the rormula . ~ C C ~ _ _ ~ CH
: Al R2 wherein at least 60% of said unlts are jolned directly to one another so as to provide segments contalning at least slx of sald units and whereln Rl, R2, R3 and R4 are lndlvldually hydrogen or alkyl groups containlng up to 8 carbon atoms each. ~he inventlon also relates to ~; methods of preparing the polymers and to articles whlch employ them.
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The polymers of the present lnvention are highly ~ active ln altering the surface propertles of substrates, ;,~; for example, relatlve to adheslon and hydrophoblclty, and ~ are capable of forming compatible~(i.e. homogeneous) blends r ~ ~ 20 wlth high and low moleoular weight thermoplastic and thermosettlng resins and polymers. Additionally the ;
polymers o~ this invention can be used to prepare graft copolymers having deslrable physical characteristlcsO
~- Thus, substrates coated with polymers Or the invention exhlblt lmproved adhesion to varlous surfaces~
~ j For example, pressure-sensitlve adhesives exhlbit lmproved '.~ adhesion to polyester and polyolefin films coated with poly-2,5-oxolane-contalning polymers.

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Additlonally, normally hydrophobic surfaces can be rendered hy~rophilic when coated wlth polymers of the invention. This ls of partlcular use when the polymers are employed on polyester films (e.g. polyethylene terephthalate, copolymers of terephthalic acld and lsophthalic acid with ethylene glycol etc.) and polyolefin fllms (e.g., poly-propylene films). Such fllms are not readily receptlve to water-based lnks and dyes unless first sub~ected to relatlvely complicated treatments (e.g., using corona dlscharge techniques, etc.). It has now been found that the same r-esult can be obtalned by slmply treatlng such normally hydrophoblc films wlth the polymers of the invention.
The abllity of the polymers to form compatible blends with a number of other polymers and resins is both unusual and valuable. While certain polymers are known to be compatible with other polymers and resins, this char-acterlstic is very unusual. Thus the opportunlty for blending polymers to obtain mixtures having desired properties is normally very limited.
The broad compatlbility of the poly-2,5-oxolany-lene polymers of the present invention is o~ great value.
Homogeneous blends of the polymers with other polymers result ln products having prope~ties different from either component alone, e.g. such blends have a single glass transition temperature. Thus a thermoplastic palymer with which the polymers of the inventlon form a homogeneous blend (such as polyvinyl chloride, chlorlnated polyvinyl chloride and polymethylmethacrylate) can be permanently plasticized by the addition of an amount o~ a polymer of the invention. Additionally, the brittleness and~or lack of adhesion to substrates frequently encountered with thermosetting reslns (such as epoxy resins) can often be overcome by blendlng an amount of a polymer Or the present inventlon thereln prlor to curlng. The polymers of the lnventlon are compatible wlth such other polymers ln all proportlons. Normally, however, the compatible blends contain from about 1 to 90 weight percent of the polymers of the invention and from 99 to 10 welght percent of the said other polymers.
The polymers of the present lnvention may be homopoly-2,5-oxolanylenes or they may be copolymers con-talning segments of 2,5-oxolanylene unlts together with substantial amounts of other unlts. Preferably the polymers have molecular weights ranging ~rom about 420 to 1,500,000 tordinarily correspondlng to a degree of polymerizatlon of about 6-20,000 with respect to all recurrlng units). Preferably also the polymers contain at least about 10 percent by weight of units of type I.
:
The copolymers may be block or graft copolymers~ and the segments of units I preferably appear therein in the main polymer backbones. Both the homopolymers and the copolymers - normally contain small amounts Or defect structures due to the nature of the process for their preparation. In the ; `~ homopolymers, units containing such defect structures are . 25 limited to less than about 15 percent of the weight of the .j polymer, an amount insufficlent to have any substantial , ~ effect on the properties of the homopolymer. As wlll be ~ explained hereinafter, such defect structures include the ,~ addition products of fragments of nucleophiles or electro-,~ 30 philes used as ring expansion inltiators, solvent fragments~
` etc.

-3-, :

wherein Rl, R2, R and R4 are, individually, hydrogen or alkyl groups con-taining up to 8 carbon atoms each, provided that the totality of such segments in the polymer contain from about 20 to 100 mole percent of type I units of which at least 60 percent are joined directly to one another so as to provide uninterrupted chains of at least 6 such units, 0 to 80 mole percent of type II units and 0 to 20 mole percent of type III units.
In another aspect, the invention provides a method of preparing a polymer containing recurring units of the formula _ / \ / R3 H-C - C-H
l R4 wherein at least 60 percent of said units are joined directly to the other so as to provide segments consisting of at least six of said units; and wherein Rl, R2, R3 and R4 are, individually, hydrogen or alkyl groups containing up to 8 carbon atoms each which comprises (i) substantially epoxidizing a precursor having the repeating :.~ unit :~ H
.-- C C--C C--and (ii) treating the resultant epoxidi~ed precursor in the presence of a minor amount of an initiator selected from strong nucleophiles and strong electrophiles to initiate polymerization of oxirane rings by a ring opening mechanism.

The invention also provides a compatihle blend of the polymer -4a-~3' ~6~

Other structures which can be present in the polymers of the inven-tion include units resulting from the incomplete reaction or non-reaction of units of the poly-1,4-dienes from which the present polymers are prepared ~as will be explained hereinafter), i.e. units of the types -1-1 /\ 1-1 C - C - C - C~

and C - C - C C ~ III

R R

wherein Rl, R2, R3 and R4 are as previously defined.

Thus, the present invention preferably also provides a polymer containing segments consisting essentially of lmits of the formulae R ~ / \ C/ ~ ~__ H-C - C-H
l R4 H / \ H
- C - C - C C - ~ II

- and H H
- - C C _ C - C - -------- III
ll l2 R3 l4 ~' 13 3~

defined above and a second polymer selected from polymethylmethacrylate, polyvinyl chloride, chlorinated polyvinyl chloride, epoxy resins and poly-esters.
The polymers of the invention are thus prepared in two steps from a polymer precursor which contains one or more A segments having a perfectly recurring structure of type III units R R R R Segment A

where x is the number of times that each unit III recurs in segment A. Thus, ~" a single A segment continues so long as the sequence of recurring main chain olefin groups, each separated from the next by two main chain carbon atoms, continues. The termini of each segment A are either one or both polymer chain ends or any anomalous (different) group ~; ' ;~:
~ ' :~

"::

,, -'Y,~ ~

: .
~:
, X~
., I .
:

`~ -4~-., ;~
,~
,~ ~

which intervenes between these segments. Such anomalous groups wou~d, for example, lnclude 1,2- or 3,4-diene addition products l~3 - CH
~1 ~2 lncorporated comonomer units, e.g. a single styrene unit or a recurrlng segment or block of styrene units. It ls important that these lntervening or anomalous groups be of such a character that they do not interfere wlth the sub-sequent epoxldation reaction, which ls discussed below.
In any polymer used as a precursor ln the present process, the tYpa III unlts must amount to not less than 80 percent o~ all dlene units thereln (i.e. a minor amount, not more than 20 percent may be diene unlts containing unsaturation ln the side chains, such as 1,2-and 3,4-butadiene units)O Also at least about 50 percent of all type III units ln the precursor polymer must be present ln A segments which contain at least 10 units.
The precursor polymers may range in degree of polymeriza-tion from about 6 to 20,000 with respect to units of type III. The range of from about 100 to 4,000 is most preferred, however, since the polymers of the invention prepared from them generally have the best balance of physical properties (eOgO, acceptable ~ensile strength combined with acceptable handling characteristics).
Sultable precursor polymers can be provided ln various ways. For example, natural rubber and gutta percha constitute such precursor polymers in which essentially the entire high molecular welght polymer ls constituted of one such segment (1,4-poly-cls~isoPrene and 1,4-polY-trans-isoprene, respectively). They may also be provided using synthetic routes well known to those skilled in the art. Thus, 1,3-diene monomers may be anlonically poly-merized (e.g., using butyl lithlum as initlator in a non-polar solvent such as cyolohexane) to provide a suitable precursor polymer in which 1,4-addition predominates over 1,2-addition to yield segments having the requislte structure described above, whlch recur within the polymer backbone. In thls case, however, 1,2-addition usually occurs to the extent of 5~20 percent to give rise to anomalous lntervening groups separating the recurring A
segments. Zlegler polymerization of 1,3-dienes, in which one or more transitlon metal compounds ls used as initiator, is a highly preferred method of providing precursor polymers because the grèat predominance of 1,4 addition gives polymers typically containlng 95-99 welght percent ;~ of A segments. Another way of providing sultable precursor polymers contalning a large proportlon of A segments ls by the use of specified transition metal lnitiators to polymerize cyclobutene, as de~cribed by G. Natta et al, MakromolO Chem. 91, pps. 87-106 ~1966).
When the polyme~s are prepared from ~opoly-1~4-dienes, the units resulting from the other comonomers thereof will be presentO Such units do not enter lnto the reaction by which the 2,5-oxolanylene units (I) are formed and ordlnarily come irlto the copolymers of the present in-vention from the precursors unchanged. Such units lnclude for example the type ~, "

--C C r--- IV

wherein R5 is hydrogen or methyl and R6 is phenyl, cyano or -CooCH3. These would be present as a result of the lnclusion of the anionically polymerizable olefins as styrene, ~-methylstyrene, acrylonitrile, methacrylo-nitrile, methylacrylate and/or methylmethacrylate as comonomers ln the precursor dienes.
Suitable precursor graft and block polymers can be prepared by techniques known to the art. For example, the graft polymers can be prepared by the free radical polymerization of ethylenically unsaturated monomers such as methylmethacrylate, methylacrylate or styrene with the appropriate polymeric precursor wlth subsequent conversion of the olefin group to the oxolanylene structure. Block polymers suitable for use as precursor polymers of the lnvention may be prepared by, for example, the techniques descrlbed in D.C. Allport and W.H. Janes, "Block Copolymers", Chapters 3 & 4, Halstead Press, 1973, and in M. Sr~warc, "Carbanions, Living Polymers and Electron Transfer Process", Interscience Publishers, 1968. Representative commerclally available block copolymers suitable for use in preparing polymers of the lnventlon include polystyrene-polybutadienP-polystyrene block copolymers, polystyrene-polyisoprene-polystryene block copolymers.
It will be appreciated by those skilled in the art that A segments, when they recur within the polymer molecule, will normally be present in a relatively wide distribution of lengths. However, knowledge of the number of III units relative to the number and type of anomalous groups or segments whlch separate A segments makes lt possible to calculate the median A segment length x (using standard probabllity theory). The term, median segment length, as used herein connotes that largest value of x, i.e. the segment length, wherein half of all the mass of the units Or a particular type recurring in the polymer (especially type I units) occur in segment lengths equal to or greater than xO
The epoxidation of the polymer precursor is normally performed so as to convert substantially all main chain olefin groups into oxlrane groups. When such con-verslon is quantitative, all III units are converted to II type units to form B segments having a perfectly recurring structure of such units O --- CH - C - C - CH - - Segment B
l ~2 l3 l4 x which have the same median segment length x as the A segments of the precursor polymer. To the extent that epoxldation falls short of con~erting 100 percent of the III units, commensurate reductlon in the median B segment length occurs. In any event, it is critical that the epoxidized polymeric lntermediates used to prepare the polymers of ; this in~ention also have the median B segment length x of at least 10.
The epoxidlzation is generally carried out by ~he reac~ion of the precursor with a peracid (e ag ~ ~
peracetic acid). Typically, the reaction ls carried out ':

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at about 30C. or less and at atmospheric pressure using stoichlometric amounts Or the reactants. After the reactlon has been completed, the polymer is recovered from the reaction mixture by, for example, precipitation, and the precipltate is purified and dried.
In the ring expansion step of the process, an appreciable fraction of the oxirane groups ln the B
segments of the epoxidlzed polymer is converted to type I units. It is a particularly significant aspect of the inventlon that polymers containing B segments having the ~ requisite structural features discussed previously can be - made to undergo an lntramolecular (more specifically --an lntrasegmental) chain reaction in which a large fraction of the oxirane groups within the B segments are converted to ring-expanded, recurring ?,5-oxolanylene units.
The hypothesized course of the reaction is as follows (shown separately for nucleophllic and electrophilic initlation).

.~ ~

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'~
~,~
''''~ ' Nucleophlllc Initlation --c c fc c--~c--c=c--c~
Epoxidatlon o ~I o -c c~ `c--c~c--c~--b--c~
Initlatlon by ~
Nucleophlle (Q ~ ) --C--C--C--C~ C/\C--Ring Expansion --c--c--c~b ~I c--c~--c ~c~ ~c--c~n l c c ~I

C - QC - C/ \C - C/ \C C ~ C - C/-\C - ~
~ `lcc-l L
¦ n-2 Termination by trans~er ~
~: to solvent or Catalyst ~H ~ ) .
0\ ~ ~ /O\ /OH
C C C G - C C- - C
: I I I I
~ C C C - C n-l :

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Electrophilic Initiation C ~C--C C ~C C=C--C~

Epoxidation /o\ ~ /o\
C - C--C C~C---C--C--C

Initiation by - Elec~rophile (Z ~ ) H

C C/~\C~C--C--\C- C~
~ I
Rlng Expan~lon --c I--c~ b--c~ cA
C C

C CH C/ \C _ ci \~ - C/- ~ C G b_ c~
C C C ¦ n-2 Terminatlon by transfer to Solvent or Water (W) --C--C--C/ ~C ~C/ \C~ C /
C - C Lc - CJ n-l ~' ,:;

,~

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Thus it appears that the lnitiatlon step proceeds via the cleavage of a randomly situated oxirane ring located within a B segment to generate a reactlve lonlc intermedlate The latter then reacts wlth an ad~acent oxirane ring to start an lntramolecular chain propagatlon reaction in which an uninterrupted sequence of ad~acent oxirane groups is rapldly converted to an uninterrupted sequence of 2,5-oxolanylene groups ~oined one to the other. Thls chaln propagatlon (or ring expansion) reaction proceeds wlthin a slngle B segment of the polymer molecule until a terminus group of that segment is encountered and : .
chain termination occurs. It is believed that this ` termination generally entails a chain transfer reaction with either an initiator or a solvent molecule to append a i~ 15 new termlnal group, e.g. a hydroxyl or methoxyl group, and generate a new initiating lonj e.g. a proton in the case of an electrophillcally initlated ring expanslon reactlon, or a hydroxide or methoxide ion in the case of a nucleo-phlllcally lnitlated ring expansion reactlon. The thus ~enera~ed lon is then free to lnitiate a similar ring ,: ~
expansion reaction on another oxlrane segment situated either on the same polymer backbone or on the polymer backbone of a different moleculeO
It follows that:
(1) The requislte structural features set forth for polymers containing B segments must be met in :~, ;~ order to support the formation of 2,5-oxolanylene c:

~; units in the necessary numbers and arrays (i e.

~;; segments containing consecutive oxolanylene :j ~
~ 30 groups).
,',"' ~'~
'~
:

(2) The longer a particular B segment, the more likely lt ls to undergo the ring expansion reaction. Even at relatively low oxirane conversions (e.g., 20 percent), relatively long segments of recurring 2,5-oxolanylene groups are produced.
(3) The median segment length of recurring 2~5-oxolanylene groups ls a function both of the weight median length of the B segment from which they were derived and the overall degree of conversion of oxlrane grouPS at the point at whlch the ring expansion reaction is terminated.

(4) The median length of the segments produced toward the end of the ring expansion reaction is smaller than that of the segments produced near the beglnning thereof.

(5) Polymers in which the epoxldized B segments constitute at least 97 percent of the weight ~0 of the total polymer chain (derlvable from natural rubber, gutta percha and polymeric dienes made with Ziegler~type initiators) can be made to yield ring-expanded products in which 2~5-oxolanylene units recur in extremely long segmentsj e.g. weight average segment lengths of 100 or more.
The ring expanslon reaction is carried out in the presence of an lnitiator selected from reagents which are known to lnitiate homopolymeri~ation of oxiranes by a ring opening mechanism, but whlch preferably do not undergo 3~

addition reactions with the oxirane groups. Partlcularly useful initlators are strong nucleophiles (tertiary amines such as trialkylamines, e.g. trlethylamlne, and alkali metal and quaternary ammonium hydroxides~ especially the preferred tetraalkylammonlum hydroxldes, e.g. tetrabutyl ammonlum hydroxide) and strong electrophiles (Br~nsted and Lewis acids such as phosphoric acid, hydrochloric acid, SbF5, AsF5 and BF3 and other electrophiles including bis~trifluoromethylsulfonyl)bromomethane, the diethYl ether complexes of Lewis acids such as boron trifluoride diethyletherate, and organometallic initiators such as Al(C2H5)3 H20. A minor amount of initlator (e.g., from about 0.1 to 10 mole percent, based on the amount of oxirane present) is used.
Normally the rlng expansion is carried out in a polar solvent such as 1,4-dloxane or a mixture of dioxane and methanol at from about -50 to 150C. and takes from about one to 16 hoursO The severity of the conditions (iOeO time and temperature) are directly relatable to the activlty of the initiatorO It is known that electrophilic initiators are generally more reactive with these types of oxiranes and thus milder reaction conditions (e.gO 1 to 8 hours at -50 to +30~Co) can be employed when an initiator such as SbF5 is usedO Nucleophilic initiators generally requlre more stringent condltions, e.gO 2 to 16 hours at 50 to 150Co The reactlon may be terminated at any time , prior to complete conversion o~ the oxirane units to oxolanylene unitsO Alternatively, the ring expansion can .-~ be carried out in the solid state by adding the inltiator ;'~
,:~

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to the epoxldlzed precursor, coating the combination onto a substrate, drying and heating at, for example, 100C.
The resultant polymer ls then recovered by precipitatlon from water and may be ~urther purified by redissolving and repreclpitating.
As prepared, the polymers of the inventlon are water-insoluble (i.e. are less than about 2 percent soluble ln water at 25C.) and cannot be spontaneously dispersed in water. However, such polymers may be made water-dlsperslble and/or water~soluble by means of post-reactlons (reactions by which certaln structures are appended to already formed polymers o~ the lnvention).
Such structures are convenlently added by the ionic opening of oxirane rings remaining ln the polymer (in units of type II above) by reactlon wlth elther an electrophilic or a nucleophillc ring opening reagent to form units of the formula H OH Y H

ll ¦2 i3 1 V
where Y ls the radical corresponding to the ring opening reagent having the structure Y-M wherein M is hydrogen or~
an alkall metal. Common Y radlcals are, for example, - hydroxyl, amino, sulfo, alkoxyg aroxy, thiol, carboxylate :~ 25 ester and alkylthla whereln the indivldual aliphatic groups (eOgO, in the amino, alkoxy, carboxylate ester and - alkylthia groups) contain no~ more than 8 carbon atoms and , ; the individual aryl groups (in the aroxy) contain not more t'nan 6 carbon atomsO 15-'~

The followlng are 80me of the preferred sub-classes of the polymers of the lnventlon:
Those polymers consisting essentially of from about 10 to 100 percent Or units o~ type I, from about 0 to 90 percent of units of type II and from about 0 to 10 percent of unlts of type III.
Those polymers which conslst essentiallY f from about 20 to 100 mole percent of segments or blocks of units Or type I and from about 0 to 80 mole percent of ~; 10 segments of units of type II.
Homopolymers in which Rl, R2, R3 and R4 are each hydrogen or in whlch R~, R2 and R4 are hydrogen and R3 is an alkyl radical, most preferably methyl.
Preferably the number average molecular weight of the polymers of the invention is at least about 420 and - not more than about 200,000. Normally and preferably also, the polymers of the invention are substantially completely - soluble ln chloroform at 20C, and to the extent of at :
least 10 parts by weight of polymer in 90 parts by weight ~-- 20 of chloroform.
The structure o~ the oxolanylene-containing polymers of the invention can be demonstrated by proton nuclear magnetic resonance (NMR). For example, the analysi of a 2,5-oxolanylene polymer derived from cis-1,4-polybutadiene was run in deuterochloroform as the solvent and all chemlcal shifts (i.e. absorptlon peaks~ were reported in parts per million ~ppm) from tetramethyl-silaneO The peak assignments were as follows:

':

A. The epoxide precursor _ _ 3.0 ppm ("cls11) / \ ~ 2.8 ppm ("trans") -CH2 - CH - Cl-l- CH2~ _ l.7 ppm B. The oxolanylene product / \ ~ 3.9 ppm . - CH CH -: H2C - CH ~
1.7 ppm CO Typlcal "other" functional groups CH3 ~ - - 3.4 ppm I
. ~ CH2 CH CH -~; 15 ~ - - 3.4 Ppm '~ 3.4 ppm -The "other" functional groups in C are typicaliy initiatlon and terminatlon sites of a sequence of 2,5-oxolanylene units. They may result from transfer to the catalyst, or reaction solvent, etcO The assignments set forth in C are for groups whlch result when an epoxldlzed polybutadiene is ring expanded in the presence of tetramethyl ammonium methoxlde in a solvent blend of methanol and dloxane (90 p~rcent).
Transition temperature measurements (particularlY
the Tm, the crystalline melting temperature) at various stages of conversion of the epoxidized polymers to the polymers of the invention demonstrate that segmented copolymers having sequences of I and II type unlts are belng formedO These segmented copolymers provide a useful . -17-method of varying the physical propertles of t~e polymers of the lnvention (since lt ls possible to stop the con-version from the tough, strong, epoxidized polymer to the elasto~eric, compatible oxolanylene polymer at any point).
The formatlon of segmented polymers also verlfies the chain reactlon mechanism proposed for the ~ormation of the oxolanylene segments. Thus, a polymer consisting of type II units derived from poly-1,4-butadiene has a crystalline melting point at 80C. This crystalllne transitlon is present after 70 percent of the II units have been con-verted to I units. It is well known that a crystalline transition in a Polymer is only present when the polymer units are present in an uninterrupted and regular sequence.
Therefore the remaining 30 percent of type II units must ` 15 be present in sequences. This then dlctates that the type I units formed are also in sequences.
- The following examples further illustrate the present invention.

"`' Example 1 A polymer o~ the invention prepared from cls-1,4-polyisoprene.
The following two solutions were prePared:
Solution A
cls-1,4-polyisoprene100 grams (number average molecular weight, Mn= 100,000) dichloromethane 2000 ml.
Solution B
.~
' peracetlc acid solution* 353 grams sodium acetate (buffering agent)24 grams :
*40% peracetic acld, 40% acetlc acid, 13% water, 5~ hydrogen peroxide and 2% sulfuric acid Solution B was slowly added to solution A from ~ a dropping funnel over a two hour period~ the temperature :
;~ o~ the mixture being maintained below 5C. The mlxture was then reacted for an~additional 30 minutes while ; malntalning a temperature less than 5C. The resultlng epoxidized polymer was precipitated in methyl alcohol and washed four times w1th oopious quantities of methyl ; : alcoholO The polymer was 98 percent epoxldized.
The following lngredients were charged to a reaction vessel in a nitrogen atmosphere:
epoxidized polyisoprene (from above) 2 grams dimethyl sulfoxide (reaction solvent) 40 grams orthophosphoric acid (catalyst or initiator) 0.12 gram The reaction mlxture was malntained under nltrogen for 16 hours at 100C. wlth agltation. The resultant 2,5-oxolanylene polymer o~ the invention was then precipitated and washed with water.
In a slmilar run 2 grams of epoxidlzed poly-isoprene, 40 grams of 90/lO dioxane/water solvent and 0.2 gram of (CF3S02)2CHBr catalyst or initlator were reacted under the same conditions. Analysls o~ the polymer indlcated that about 75 mole percent of the oxirane groups had been converted to 2,5-oxolanylene unlts and that at least 60 percent of these units were ~oined one .
to the other ln segments conslsting of at least 6;of said units.
:' Example 2 A polymer of the invention prepared from cis-l, 4-polybutadiene.
;
The following two solutions were prepared:
Solution A
cis-1,4-polybutadiene150 grams (M = 9g2i analysis 98%
ma~n chaln olefln units of type III, 2% vinyl units resulting from 1,2-butadiene addition) methylene chloride3000 ml.
Solution B
peracetlc acid solution 530 grams (as described in Example l) sodium acetate 36.8 grams (buffering agent) :

,.

Solution B was slowly added to solutlon A from a dropping funnel over a 40 minute period, th~ temPerature of the mlxture belng malntained below 30C. The mixture was t~en reacted ~or an addltlonal 3-12 hours whlle malntalnlng a temperature o~ less than 25C. The resultlng epoxldized polymer was preclpitated ln methyl alcohol, redlsso~ved in p-dioxane and repreclpitated in distllled water~
The polymer was 98 percent epoxldized.
The followlng lngredlents were utilized in converting the epoxldlzed polymer to a polymer of the inventlon:
~; polybutadlene 20 grams (98% epoxidlzed) dioxane (reaction solvent) 340 grams ~` distilled water 40 grams (CF S0 ) CHBr (catalyst- 2 grams 50%3so~u~ion by welght in dioxane) The ca~alyst was 510wly added to the other ingredients with vlgorous agitatlon and the mixture was agitated and reacted at 25C. for six hours. The catalyst was neutralized with tetraethYlammonium hydroxlde, and the 2,5-oxolanylene polymer was recovered by precipitating and 2~ washing the polymer with distilled water.
Analysis of the polymer indicated that about 85 mole percent of the oxirane groups had been converted to 2,5-oxolanylene units and tha~ at leas~ 60 percent of these units were Jolned one to the other in segments conslsting of at least 6 of said units.

Example 3 A polymer of the lnventlon conslsting essentlall~
of units of types I and II.
Epoxldized cls-1,4-polybutadlene was prepared as described ln Example 2. A solutlon of 30 grams of the polybutadlene in 730 grams of dioxane was warmed to 75C., and 111 grams of a 10 percent by weight s~lutlon of tetrabutylammonium hydroxide in methanol was added. The mlxture was reacted ln an inert atmosphere at 75C.
Individual samples were removed from the reactlon mixture after one, 4 and 8 hours. These samples were precipltated lnto one llter of water and soaked for 16 hours. The samples were then dried in a desslcator over P205 at 1 Torr for 72 hours.
The samples were analyzed to determine the relative concentration of the oxolanylene and oxirane unlts in the polymer. The results were as follows:

Sample Mole ~ Mole % Mole %
Tlme Polyoxirane Polyoxolane Other*

201 hour 68 30 2 4 hours 24 73 2 8 hours 12 85 2 ...
.i:
.. . .
*prlmarily vinyl The samples and the epoxldized polybutadiene startlng materlal (sample tlme = 0 hr.) were also analyzed by differential thermal analysis to determlne the transltion temperatures of the polymers. The reæults were as follows: -.~

Sample Mole % ~ole % Mole %
Time Polyoxlrane Polyoxolane Other Tg(C) Tm(C) .. .. ..
0 hour 98 0 2 -12 80 1 hour 68 30 2 ~3 76 4 hours 24 73 3 19 77 8 hours 12 85 3 25 none :
The ~oregolng shows that as the converslon of oxirane units to 2,5-oxolanylene units lncreases, the glass transitlon temperature (Tg) of the product increases.
These data further show that as the number of oxirane units becomes small, the polymer ceases to exhlbit a melting point (Tm). Thls is consistent wlth the conversion of the oxlrane groups to 2,5-oxolanylene groups in the chain reaction as prevlously explained.

Example 4 Polymers of the lnventlon prepared from epoxldized in~ermedlate polymers in whlch the length of ;~ the B segments varies. ~
Two different polybutadlenes were employed as precursors. The ~lrst ~içne (BDl) had an Mn of lI,000 and comprised 9 mole p~rcent vinyl units, 38 mole percent cls-1,4-butadiene units and 53 mole percent trans-1,4-butadiene units. The second (BD2~ had an Mn of 98,000 and comprises 98 mole percënt cis-194-b~u~adiene units and 2 mole percent 1,2-vinyl units.
The precursor polymers were epoxidized with varylng stiochiometrlc concentratlons of peracetic acid to achieve varying degrees of epoxidatlon, thereby providing intermedlate polymers in which the median /

length of the B segments varied widely. Epoxldation was carried out in methylene chloride over a period of about 6 hours using conditions similar to those described in Example 2. The epoxidized polymers were anlyzed by NMR to determine the relative concen-tratlon of the various units in the polymer. The precursor diene polymer and peracetic acid charges used and the results obtained were as follows:

10 Charge ~ oxidized Polymer Composition Polymer Peracetic Cis~ Cis"Oxi- 'ITrans"Oxi-Lot (gms) Acid Vinyl diene(l) rane(2) rane(2) 15III 100 BD2 356 2 _ 98 IV 150 BDl 540 9 - 38 53 (1) Type III units (2) Type II units These epoxidized polymers were reacted (as

6-8 percent solutions by weighk in 90/10 dioxane/
methanol) at 80C. for varying periods of time in the presence of a catalyst. The resulting polymers were precipitated in distilled water and dried over P205 at 0 Torr for 24 hours. Solutions of 0.2 percent by weight of the pol~mers in CHC13 were prepared and concentrated to removal all volatile impurities.
~ When the solutions had been concentrated to 10 ; percent solids, thin films of the solutions were cast onto tetrafluoroethylene sheets. The ~ilms were air dried for 16 hours and vacuum dried over P205 at 1 Torr for 24 hours then redissolved in deuterochloro-3~

form at 10 percent solids by weight and analyzed by NMR to determine the relative concentrations of the various units in the polymer The reaction times and results were as follows:

Product Pol~mer Composition (Mole%) Epoxidized Catalyst Rxn.
Polymer (Moles%) Time 1,2- 1,4 Oxolan-Lot Lot (1) (hrs) diene diene Oxirane ylene Other B I 10 8L~ 2 29 36 22 12 D II 10 84 2 ~ 19 58 13 G III 10 84 2 _ 9 85 3 (1) The mole percentages of the catalyst, (CH3)4NOCH3, are based on the original olefin content of the starting polydienes.

Less than ~0 percent Or the oxolanylene units in polymers A and B are in segments in which at least six such units are directly ~oined (as shown by statis-tical analysis). Therefore polymers A and B do not ~ 25 fall within the present invention. The remaining ;~ ~ polymers (C-J) do fall ~ithin the invention, however.
These data demonstrate that the formation , of 2,5-oxolanylene units requires that the oxirane groups be present in type _ segments, i.e. separated by no more and no less than 2 main chain carbon atoms.
Thus, polymers prepared from epoxidized polymer I
~9 mole percent oxirane) greatly limit the conversion of the oxirane units to oxolanylene units.

., s 3~4 The data further demonstrate that formation of the oxolanylene units is the ma~or cause of the reduction in oxirane units since, aside from the formation of the oxolanylene units, there is relatively llttle oxirane depletion. Thus, it is clear that the ring expansion reaction wherein the oxolanylene units are formed is a chain process in which a random cleavage of an oxirane group initiates and promotes the formation of 2,5-oxolanylene units. Furthermore, the average length of the resultant oxolanylene units bears a direct relationship to the average length of the average oxirane segment.

Example 5 A polypropylene film rendered hydrophilic by a coating of a polymer of the invention.
One part by weight of a polymer of the invention prepared as described in Example 4F was dissolved in 99 parts by weight isopropyl alcohol.
An oriented 2 mil polyproyplene film, having a water contact angle of 100, was dipped into the polymer ~ solution and dried at 100C. for 10 minutes. The ;~ resultant coated film had a water contact angle of 30. The coated film was soaked in water for 16 hours and still maintained a contac~ angle of 30.
The coated film was then soaked in methyl alcohol for 16 hours and still maintained a contact angle of 30.
The coated film was inked with water-based lnk, and the ink adhered thereto. The ink did not i3~1~

adhere to uncoated polypropylene fllm.

Example 6 A polyester film rendered hydrophilic by a coating of a polymer of the invention.
One part by weight of a polymer prepared as described in Example 4F was dissolved in 99 parts by weight of tetrahydrofuran. Polyester film having a water contact angle of 67 was dipped into this solution. The film was then dried in a 130C.
forced air oven for five minutes. The water contact angle on the resulting coated film was reduced to 10.
This primed film demonstrated improved adhesion to polar materials. The improved adhesion was demonstrated by application of a strip of pressure-sensitive tape to coated and uncoated polyester film. The tape adhered only weakly to the uncoated polyester film but adhered tenaciously to the coated polyester film.

Example 7 Post-reaction o~ a polymer of the invention ~ with sodium sulfite to render it water-dispersible.
; A water-disperslble polymer according to the invention was prepared by dissolving ten grams of polymer F of Example 4 in a mlxture of 100 grams of tetrahydrofuran and 100 grams of water at 60C.
Five grams of tetrabutyl ammonium bromide and 10 grams of sodium sulfite were added to the solution and the resulting mlxture reacted for five days with agita-tion. The resulting polymer was water-dispersible and thereby useful for coating from aqueous systems.
This water-dispersibility was achieved by the open-ing of resldual oxirane groups in the polymer andthe addition of sulfo groups to the polymer at those locations.

Post-reaction of a polymer of the invention with dimethylamine to render it water-dispersible.
A water-dispersible polymer according to . ~ .
the invention was prepared by dissolving ten grams of polymer F of Example 4 in 100 grams of methyl alcohol. Forty grams of a 40 percent by weight solution of dimethyl amine in water was added to the solution and the resulting mixture reacted for three hours. A water-dispersible polymer was obtained as a result o~ the opening of residual oxirane groups in the polymer and the replacement of the oxirane oxygen thereo~ by hydroxyl and amino groups. Nitrogen analysis showed 3.8 percent N, indicating that 30 percent of the residual oxirane groups had been converted to tertiary amino alcohol groups.

;~ Example 9 Gra~t copolymers accordlng to the inven-tion.
- Two graft copolymers according to the invention were prepared from the following materials:

3~
A B
Polymer F of Example 4 3 grams 3 grams Methylmethacrylate3 grams Dodecylmethacrylate - 3 grams Toluene 18 grams 18 grams t-Butyl hydroperoxide 0. o6 gram 0. o6 gram The solutions were placed in a sealed vessel in an oxygen-free atmosphere and reacted for 40 hours at 70C. The resulting polymers pro-vided clear solutions and, when cast, clear films.
Sample B was analyzed in detail. A film was dried at 1 Torr, redissolved in deuterochloro-form and analyzed by proton MNR. The resulting film comprised 46 mole percent polydodecylmethacrylate segments and 54 mole percent of polymer 4F segments.
The solubility characteristics of the polymer demon-strated that it was a graft p~olymer. Thus the pGlymer was not soluble, although highly swollen, in methanol. Methanol is a solvent for poly-2,5-oxolanylene but is not a solvent for polydodecyl-methacrylate. Moreover, less than 10 weight percento~ the polymer could be extracted with methanol.
Additionally, the polymer was not soluble in hexane.
Hexane is a solvent for polydodecylmethacrylate but is not a solvent for poly-2,5-oxolanylene.
Again, less than 10 weight percent of the polymer ; could be extracted with hexane. Furthermore, the polymer was soluble in solvents for both segments such as toluene, tetrahydrofuran and chloro~orm.

Example 10 Compatible blends of a polymer of the inven-tion with thermoplastic polymers.
The polymer of sample F of Example 4 was dissolved in tetrahydrofuran to form a 6 percent by weight solution. Separate portions of the solution were added to solutions t10 percent by weight in `~ tetrahydrofuran) of various thermoplastic resins.
The resulting solutions were clear. The solutions were poured into separate petri dishes and allowed to air dry for sixteen hours. The drled samples were then placed in a forced air oven at 100C. to drive off any residual solvent. The resulting samples were clear and flexible. The glass transition temperature of the samples was measured by differen-tial thermal analysis. The results of the transitiontemperature determinations are listed below:
Polymers Weight Ratio Tg(C) -~ Polymethylmethacrylate 100 102 (PMMA) Polyvinylchloride100 81 (PVC) Poly-2,5-oxolanylene 100 25 ~ (POX) ; PMMA/POX 50/50 55 In all cases only a single glass transition temperature was noted. The film clarity, flexibility - and glass transition temperature data (i.e. a single Tg which is intermediate between the parent polymers) are convincing evidence of compatible polymer blends.

Example 11 Compatible blends o~ a polymer of the invention with epoxy resins.
Polymer I of Example 4 was used to form compatible mixtures with various epoxy resins. The mixtures were applied to a vinyl surface and cured to^form coatings. The following formulations were prepared and applied:

Polymer I Epoxy Resin Photoactivator(3) Solvent(4) Lot (grams) (grams) (grams) (grams) A 0-05 0.45 (1) 0.025 5 B 0.1 0.4 (1) 0.025 5 C 0.2 0.3 (1) 0.025 5 D 0.3 0.2 (1) 0.025 5 E 0.4 0.1 (1) 0.025 5 F 0.1 4 (2)s 0.025 5 (l) o~H 2-0-C ~ ~o 20~ Epoxy equivalent weight (EEW) 133.

(2) ~ -CH20-C-~-CH2 ~ C~ -C ~ o Epoxy equivalent weight 213.

(3) Four parts diphenyliodonium hexafluoro-phosphate and one part 2-chlorothioxanthene.
(4) Tetrahydrofuran.

.

~63~4 After coating, the solutions were allowed to air dry 16 hours and then 10 minutes in a 100C.
forced air oven. At this point the coatings were clear and tacky. The coatings were then photocured by placing them 10 centimeters away from a sunlamp (250 W. - General Electric) for five minutes. The cured coatings remained clear and demonstrated increased flexibility, adhesion and solvent resis-tance (resistance to methyl ethyl ketone) when compared to control coatings containing no poly-2, 5-oxolanylene.

Example 12 -Compatible blend of a polymer of the inven-tion with a thermosetting polyester resin.
Polymer F of Example 4 was added to a free radically curable thermosetting polyester resin. The following mixture was prepared:
Polymer F 10 grams Styrenated polyester resin* 1 gram Benzoin ethylether 0.01 gram . -- , ~Polyester of 1 mole isophthalic acid, 1 mole maleic acid and 2.2 moles pro-pylene glycol. The resin is 1 part styrene to 2 parts polyester.
The clear solution was cast onto a poly-ethylene terephthalate film, and the solvent was driven of~ by drying in a 100C. oven for 10 minutes.
The resulting clear and tacky film was exposed to a 250 W. sunlamp at a distance of 10 centimeters for 3~

ten minutes. The resulting fllm was a perfectly clear, leathery material having excellent adhesion to the polyester film. When the polyester resln alone was cured wlth benzoin ethyl ether, a brittle, glassy film was obtained which had poor adhesion to the polyester film.

Claims (10)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A polymer containing recurring 2,5-oxolanylene units of the formula wherein at least 60 percent of said units are joined directly to one another so as to provide segments consisting of at least six of said units; and wherein R1, R2, R3 and R4 are, individually, hydrogen or alkyl groups containing up to 8 carbon atoms each.

2. A polymer according to claim 1 which contains at least 10 percent by welght of oxolanylene units.

3. A polymer according to claim 1 wherein R1, R2, R3 and R4 are each hydrogen.

4. A polymer according to claim 1 wherein R1, R2 and R4 are each hydrogen and R3 is methyl.

5. A polymer containing segments consisting essentlally of units of the formulae I

II
and III

wherein R1, R2, R3 and R4 are, individually, hydrogen or alkyl groups containing up to 8 carbon atoms each, provided that the totallty of such segments in the polymer contain from about 20 to 100 mole percent of type I units of which at least 60 percent are joined directly to one another so as to provide uninterrupted chains of at least 6 such unlts, 0 to 80 mole percent of type II units and 0 to 20 mole percent of type III units.

6. A polymer according to claim 5 consisting essentially of from about 20 to 100 mole percent of units of type I and from about 0 to 80 mole percent of units of type II.

7. A polymer according to claim 5 consisting essentially of units of type I.

8. As an article of manufacture, a normally hydrophobic substrate which has been rendered hydrophilic by application thereto of a coating of a water-insoluble polymer in accordance with claim 5.

9. A method of preparing a polymer containing recurring units of the formula wherein at least 60 percent of said units are joined directly to the other so as to provide segments consisting of at least six of said units; and wherein R1, R2, R3 and R are, individually, hydrogen or alkyl groups containing up to 8 carbon atoms each which comprises (1) substantially epoxidizing a precursor having the repeating unit and (ii) treating the resultant epoxidized precursor in the presence of a minor amount of an initiator selected from strong nucleophiles and strong electro-philes to initiate polymerization of oxirane rings by a ring opening mechanism.

10. A compatible blend of (a) a polymer according to claim 1 and (b) a second polymer selected from poly-methylmethacrylate, polyvinyl chloride, chlorinated polyvinyl chloride, epoxy resins and polyesters.