Arylene sulfide polymers
I Umted States Patent 1 [111 3,878,176  
 Moberly Apr. 15, 1975 [5 ARYLENE SULFIDE POLYMERS 3,268,504 8/1966 Harris et a]. 260/791 [75] Inventor: Charles W. Moberly, Bartlesville,  
  Okla Primary Examiner-Melvyn I. Marquis [73] Assignee: Phillips Petroleum Company,  
 Bartlesville, Okla.  
 [22] Filed: Nov. 19, 1973 [57] ABSTRACT [2]] Appl. No.2 416,817  
  A method of producing arylene sulfide polymers employing (l) polyhalo-substituted aromatic compounds; Us. e elemental ulfur; bases elected from the hy,  
  I id of lithium odium potassium rubidium e- [58] Field of Search 260/79, 79.1 Sium, magnesium, calcium, Strontium and barium,  
  and, (4) organic amides. [56] References Cited UNITED STATES PATENTS 15 Claims, N0 Drawings 2,538,941 l/l95l Macallum 260/79.l  
  ARYLENE SULFIDE POLYMERS This invention pertains to the production of arylene sulfide polymers.  
 In one of its more specific aspects, this invention pertains to a novel method of producing polymers such as those produced by the method of U.S. Pat. No. 3,354,129,  
  In US. Pat. No. 3,354,129, the disclosure of which is incorporated herein by reference, there is disclosed a method of producing polymers from polyhalosubstituted aromatics, alkali metal sulfides and polar organic compounds. There has now been discovered anothermethod of preparing arylene sulfide polymers.  
  In accordance with one embodiment of the present invention, arylene sulfide polymers are produced by reacting at least one polyhalo-substituted aromatic compound with a mixture in which elemental sulfur, at least one base selected from the hydroxides of lithium, sodium, potassium, rubidium, cesium, magnesium, calcium, strontium and barium, and at least one organic amide are contacted.  
  The polyhalo-substituted aromatic compounds which can be employed in the method of this invention are compounds wherein the halogen atoms are attached to aromatic ring carbon atoms. Suitable compounds include 1,2-dichlorobenzene, 1,3-dichlorobenzene, 1,4- dichlorobenzene and the other polyhalosubstituted aromatic compounds described and exemplified in the aforementioned U.S. Pat. No. 3,354,129. If desired, mixtures of polyhalo-substituted aromatic compounds can be used.  
  The elemental sulfur which is employed in the present invention can be used in any of its allotropic forms.  
  Bases which can be employed in the method of this invention include lithium hydroxide, sodium hydroxide, potassium hydroxide, rubidium hydroxide, cesium hydroxide, magnesium hydroxide, calcium hydroxide, strontium hydroxide, barium hydroxide, and mixtures thereof. If desired, the hydroxide can be produced in situ by the reaction of the corresponding oxide with water.  
  The organic amides used in the method of this invention should be substantially liquid at the reaction temperatures and pressures employed. The amides can be cyclic or acyclic and can have I to about carbon atoms per molecule. Examples of some suitable amides include formamide, acetamide, N-methylformamide, N,N-dimethylformamide, N,N-dimethylacetamide, N- ethyl-propionamide, N,N-dipropylbutyramide, 2- pyrrolidone, N-methyl-Z-pyrrolidone, e-caprolactam, N-methyl-e-caprolactam, N,N&#39;-ethylenedi-2- pyrrolidone, hexamethylphosphoramide, tetramethylurea, and the like and mixtures thereof.  
  The components used in the preparation of the arylene sulfide polymer can be introduced into contact in any order. Water which can be present in any composite formed from any of the preceding compounds, for example, the composite formed from the polyhalosubstituted aromatic compound, the sulfur, the base and the organic amide or which can be present in a composite formed from the sulfur, the base and the organic amide can be removed, for example, by distillation, prior to conducting the polymerization reaction. Such water can be present as an impurity, as a solvent or diluent or as water of hydration. Regardless of whether a water removal step is employed, at least a portion of the composition formed from the polyhalosubstituted aromatic compound, the sulfur, the base and the organic amide is maintained at polymerization conditions to produce the arylene sulfide polymer.  
  The ratio of reactants can vary considerably but about 0.6 to about 2, and preferably about 0.65 to about 1.2, gram-moles of the polyhalosubstituted aromatic compound will generally be employed per gramatom of sulfur. The base generally will be employed in an amount within the range of from about 1 to about 5, and preferably from about 1.5 to about 4, gramequivalents per gram-atom of sulfur. As used herein, one gram-equivalent of the hydroxides of magnesium, calcium, strontium, and barium represents the same amount as one-half gram-mole of these substances, whereas for the hydroxides of lithium, sodium, potassium, rubidium, and cesium, the amount represented by one gram-equivalent is the same as that represented by one gram-mole.  
  The amount of organic amide employed can also vary over a wide range but will generally be within the range of from about grams to about 2500 grams per gram-mole of polyhalo-substituted aromatic compound employed.  
  The temperature at which the polymerization can be conducted can vary over a wide range and will generally be within the range of from about C. to about 450 C. and preferably within the range of from about C. to about 350 C. The reaction time will be within the range of from about 10 minutes to about 3 days and preferably from about 1 hour to about 8 hours. The pressure need be only sufficient to maintain the polyhalo-substituted aromatic compound and the organic amide substantially in the liquid phase and to retain the sulfur source therein.  
  The arylene sulfide polymers produced by the method of this invention can be separated from the reaction mixture by conventional procedures, for example, by filtration of the polymer followed by washing with water, or by dilution of the reaction mixture with water, followed by filtration and water washing of the polymer.  
  The arylene sulfide polymers prepared by the process of this invention can be blended with fillers, pigments, extenders, other polymers and the like. They can be cured through crosslinking and/or chain extension, for example, by heating at temperatures up to about 480 C. in the presence of a free oxygen-containing gas, to provide cured products having high thermal stability and good chemical resistance. They are useful in the production of coatings, films, molded objects and fibers.  
  The previous statements are based upon the following example.  
 In the following example, values for inherent viscosity were determined at 206 C. in l-chloronaphthalene at a polymer concentration of 0.4 g/lOO ml solution.  
 EXAMPLE I The method of the invention is illustrated by the data of Table I, all runs set forth therein having been carried out in the following general manner, except for minor variations indicated in the table.  
 275 grams of N-methyl-Z-pyrrolidone were introduced into a reactor. The indicated amount of sodium hydroxide was then introduced into the N-methyl-2- pyrrolidone to form a first mass. Elemental sulfur in the form of flowers of sulfur was introduced into the first mass to form a second mass.  
  The reactor was Closed and flushed by alternately pressuring with nitrogen and venting to atmospheric What is claimed is:  
 l. A method of producing polymers comprising: a. forming a composition by contacting sulfur, at least one polyhalo-substituted aromatic compound pressure. With about 0.05 SCFH nitrogen flowing into the reactor, the distillation tube was connected and the f l the halogen atoms are attached to contents of the reactor were heated to a temperature mane 3 f atoms; least &#34;1 base selefned of 196 c. That material which distilled off was colfrorn t hydrgxldes of h sodlllmmomsslllm. lected and found to consist essentially of water and fubldlumi ceslumi magneslumt Calclumi Stromlum N-methyLZ-pyrrolidone, and barium, and at least one organic amide; and,  
  When the reactor temperature reached 196 C., the be maintaining at least a Portion of Said composition reactor was cooled to about 191 C. To the contents of at polymerization conditions to pr du e said polythe reactor there was then added 1.03 moles of 1,4- dichlorobenzene in a solution of52 grams of N-methyl- The method of Claim 1 in which aid polyhalo- 2-pyrrolidone. The solution was pressured into the resubstituted aromatic compound is employed in an actor by nitrogen pressure and the reactor pressure was am unt ithin th rang f fr m a ut 0.6 to about 2 thereafter adjusted to about 5-10 psig by venting. gram-moles per gram-atom of sulfur.  
  The temperature of the contents of the reactor was 3. The method of claim 1 in which said base is emthen increased to about 246 C. and maintained at that ployed in an amount within the range of from about 1 temperature for three hours. The contents of the reacto about 5 gram-equivalents per gram-atom of sulfur. tor were then cooled to about 66 C. and the poly(p- 4. The method of claim 1 in which said organic amide phenylene sulfide) product was recovered. is employed in an amount within the range of from In those runs in which there appeared to be a low about 100 grams to about 2500 grams per gram-mole conversion to polymer, a combination of methanol of said polyhalo-substituted aromatic compound. washes and hot water washes was employed to recover 5. The method of claim 1 in which said base is sodium the polymer. In those runs in which there appeared to hydroxide and said polyhalo-substituted aromatic combe a high conversion to polymer, four hot water washes pound is 1,4-dichlorobenzene. of the product were employed. The product, in all in 6. The method of claim 5 in which said base is emstances, was dried in a vacuum at 80100 C. after the ployed in an amount within the range of from about 1 last wash, the product being swept with nitrogen during .to about 5 gram-equivalents per gram-at0m of sulfur the drying. and said 1,4-dichlorobenzene is employed in an Yields were calculated on the basis of 108 grams of amount within the range of from about 0.6 to about 2 poly(p-phenylene sulfide) as the theoretical yield from gram-moles per gram-atom of sulfur. one mole of 1,4-dichlorobenzene. 7. The method of claim 1 in which water is removed Table I Materials Employed Gram- Gram-moles Polymer Polymer Properties atoms 1.4-Dichloro- Maximum Yield S Inherent Run No. Sulfur NaOH benzene Pressure 71 Content Viscosity 1 1 1.5 1.03 300+ 24 0.02 2 1 b) 2 1.03 293 69 0.02 3 l 2 1.03 250 67 25 5(a) 0.05 4 1 2.5 1.03 0.06 5 1 3 1.03 47 25.6 0.03 6 1 4 1.03 50 26 23.5(a) lnsol 7 1.125 2.81 1.03 65 75 0.07 8 1.125 2.81 1.03(d) 81 0.11 9 1.19 2.98 1.03 65 79 0.07 10 1.19 2.98 l.03(d) 82 0.09 11 1.25 3.125 1.03 70 83 25.8 0.07 12 1.25 2.5 1.03 87 28.2 0.07 13 1.25 2.5 1.03 200+ 59(c) 0.03 14 1.5 3 1.03 262 12 0.03  
 (a) Analysis on methanol-extracted polymer.  
 (b) Sulfur dissolved in N-methyl-&#39;l-pyrrolidone in reactor prior to addition of sodium hydroxide solution.  
 (c) Reaction period was 6 hrs. at 246 C. (d) 1,4-dichlorobenzcne added at the time of initial charge.  
  It is within the scope of this invention to bring the polyhalosubstituted aromatic compound, the sulfur, the base and the organic amide into contact in any order.  
  Also, it is within the scope of this invention to remove water from any combination of the aforesaid compounds.  
 It will be evident from the foregoing that various modifications can be made to the method of this invention. Such are considered, however, to be within the scope thereof.  
 tached to aromatic ring carbon atoms to form a second composition; and,  
 c. maintaining said second composition at polymerization conditions to form said polymer.  
  9. The method of claim 8 in which said polyhalosubstituted aromatic compound is employed in an amount within the range of from about 0.6 to about 2 gram-moles per gram-atom of sulfur.  
  10. The method of claim 8 in which said base is employed in an amount within the range of from about 1 to about 5 gram-equivalents per gram-atom of sulfur.  
  11. The method of claim 8 in which said organic amide is employed in an amount within the range of from about 100 grams to about 2500 grams per grammole of said polyhalo-substituted aromatic compound.  
  12. The method of claim 8 in which said base is sodium hydroxide and said polyhalo-substituted aromatic compound is 1,4-dichlorobenzene.  
  13. The method of claim 12 in which said sodium hydroxide is employed in an amount within the range of from about 1 to about 5 gram-equivalents per gramatom of sulfur and said 1,4-dichlorobenzene is employed in an amount within the range of from about 0.6 to about 2 gram-moles per gram-atom of sulfur.  
  14. The method of claim 12 in which water is removed from said first composition.  
 15. The method of claim 13 in which water is removed from said first composition.