Copolymeric material, sulfur

Sulfur—Dicyclopentadiene Copolymeric Material as Compared with Plastic Sulfur... 

A polysulfone is characterized by the presence of the sulfone group as part of its repeating unit. Polysulfones may be aUphatic or aromatic. AUphatic polysulfones (R and are alkyl groups) were synthesized by radical-induced copolymerization of olefins and sulfur dioxide and characterized many years ago. However, they never demonstrated significant practical utiUty due to their relatively unattractive physical properties, not withstanding the low cost of their raw materials (1,2). The polysulfones discussed in this article are those based on an aromatic backbone stmcture. The term polysulfones is used almost exclusively to denote aromatic polysulfones. 

Al-Omran and Rose controlled the location and extent of sulfonation on poly (ary lene ether) backbones by copolymerizing 4,4 -dichlorodiphenyl sul-fone, durohydroquinone, and hydroquinone to form random copolymers, where only the hydroquinone residue would be expected to be susceptible to sulfonation by sulfuric acid. Although these authors observed sulfonation at positions other than at the desired hydroquinone locations, designing sulfonation sites into a polymer backbone remains an attractive strategy for producing copolymers with known structures. This allows the chemical structure and composition of the material to dictate the extent of sulfonation rather than trying to externally control sensitive and sometimes unpredictable macromolecu-lar sulfonation reactions. 

Materials. Poly (olefin sulfone)s were prepared by copolymerization of liquid mixtures of sulfur dioxide and the appropriate olefin using tert.-butyl hydroperoxide as initiator in the temperature range from —80 to 0°C. The poly (amino acid)s were obtained from Sigma Chemical Co. and used without further purification. The poly (olefin) s were provided by Mr. O. Delatycki and Dr. T. N. Bowmer and were prepared under controlled conditions. The aromatic polysulfones were prepared and purified by Mr. J. Hedrick. The purity of all polymers was checked by H and 13C NMR. 

Another group of potentially large volume plastics that is under development are the polysulfone resins, made by the copolymerization of olefins such as 1-butene with sulfur dioxide 24). Both these feed stocks could be derived in abundant quantities and at relatively low costs from petroleum sources. The polysulfone resins are moldable thermoplastic polymers having physical properties that vary widely depending on the olefin from which they are prepared. They are considered to have excellent prospects for development to a large volume, low cost commercial plastic and may permit the entrance of plastic products into other fields in which they are now limited by the high cost and inadequate supply of present thermoplastic materials. 

This is broadly in agreement with the findings from copolymerization (Table 22 and Section VI-B). The introduction of comonomer units into PTHF reduces its crystallinity and rubbery materials generally result. In one case allylglycidyl ether was copolymerized so that the pendant olefinic side chains would allow sulfur vulcanization (7). 

We are interested in the application of polymers as adsorbents, ion exchangers, fuel cells, and permeable materials. In this regard, the first resins with some of these properties were obtained by D Aleleio in 1944 based on the copolymerization of styrene and divinylbenzene. Unfunctionalized polystyrene resins cross-linked with divinylbenzene (Amberlite) are widely applied as adsorbents [191,192], In addition, the polystyrene-divinylbenzene resins functionalized with sulfuric acid (sulfonation) to create negatively charged sulfonic sites are applied as cation exchangers, and treated by chloromethylation followed by animation produce anionic resins [193,194],... 

Suspension copolymerization of 1-butene and sulfur dioxide can lead to expandable beads. The cellular material obtained has improved properties with respect to expanded polystyrene. The manufacture of expandable beads by suspension copolymerization is covered by a patent... 

Materials. Poly(3-butenyltrimethylsilane sulfone) (PBTMSS) was synthesized by free-radical copolymerization of 3-butenyltrimethylsilane with liquid sulfur dioxide (molar ratio 1 9) initiated with azobisisobutyronitrile (AIBN) at 35X in a sealed glass ampoule. The detailed preparation procedure and properties of this copolymer have been reported elsewhere. (7 3)... 

Cationic polymerization is initiated by acids. Isobutylene, for example, undergoes cationic polymerization to a tacky material used in adhesives. Copolymerization with a little isoprene gives butyl rubber, used to make automobile innertubes and tire liners. A variety of acids can be used sulfuric acid AICI3 or BF3 plus a trace of water. We recognize this process as an extension of the dimerization discussed in Sec. 6.15. 

Attempted Copolymerization of Monomer I with Sulfur. A mixture of 2.5 g of sulfur and 2.5 g of monomer I was placed in a test tube under a continuous stream of ary nitrogen. The tube was heated in an oil bath at 185°C for two hours. A viscous orange fluid was obtained on cooling, the fluid separated into two solid phases. One phase was a hard-orange glassy material, the other hard-yellow material. This... 

Allylstarch can be blended with lower alkyl itaconates in the ratio from 2 1 to 10 1 and then copolymerized with a variety of coating materials to enhance coating plasticity, drying, and hardening.1028 Allylstarch can be polymerized into insoluble products using either sulfur chloride or disulfur dichloride.1029 The reaction product of allylstarch with propylene oxide was utilized as a dispersant for petroleum emulsions.1030 Novel resinous materials have been obtained from adducts of unsaturated esters of dienophilic dioic acids and cyclic polyenic hydrocarbons with mono- and di-allyl starch.1031... 

The main aim for FCC gasoline desulfurization is to remove thiophenic sulfur compounds. Membranes made from polar polymers with solubility parameter close to thiophenic sulfur are used for desulfurization of gasolines by PV It is evident that solubility parameter of primary sulfur components of gasolines, that is, thiophenic sulfur components, is 19-21 (J/cm )", while for other hydrocarbons, these values are 14-15 (J/cm )". This difference can be exploited for separation by PV. Solubility parameter values of most of the polymers used as membrane material lie in the range of 21-26 (J/cm )". Thus, membranes made from these polymers afford good selectivity for thiophenic sulfur. Apart from various homopolymers, chemically and physically modified polymers have also been used for per-vaporative desulfurization. Some of these modifications include using different types and amounts of cross-linkers, blending two polymers, and copolymerization. Composite and treated ionic membranes have also been tried for this separation. Polymer membranes tried for this separation include PDMS/PAN, PDMS/PEI, PDMS/PES, PDMS/ ceramic, polyetherimine (PI)/polyester, PEG/PES, and PU/PTEE. ... 

The copolymerization of acrylic esters with 5%-15% acrylonitrile or 2-chloroethyl vinyl ether produces elastomers which are more heat and oxidation resistant than butadiene/acrylonitrile copolymers because of the absence of double bonds. For the same reasons, these materials are also suitable for the manufacture of gaskets and membranes for use with high-sulfur-content industrial oils (for example, crankshaft gaskets in the automobile industry). Since the side groups have poor resistance to hydrolysis, steam curing is not possible. Curing with amines can be subsequently carried out. 

The structure of the counterion present in Super Filtrol initiated copolymerizations is unknown. However, the material consists of clay-bound sulfuric acid and presumably the counterion is sulfate bound to a silico-aluminate matrix. 

One of the simplest ways to introduce the crosslinks required for rubber-like elasticity is to carry out a copolymerization in which one of the comonomers has a functionality of three or higher [9,21]. This method, however, has been used primarily to prepare materials so heavily crosslinked that they are in the category of hard thermosets rather than elastomeric networks, as it has already been mentioned [11]. The more common techniques include vulcanization (addition of sulfur atoms to unsaturated sites), peroxide thermolysis (covalent bonding through free-radical generation), end linking of functionally terminated chains (isocyanates to hydroxyl-terminated polyethers, organosilicates to hydroxyl-terminated polysiloxanes, and silanes to vinyl-terminated polysiloxanes) [18],... 

Absent from Table 10 are the comonomers carbon monoxide, carbon dioxide, and sulfur dioxide. These comonomers are not included because their copol mieiization does not obey the normal copolymer model illustrated by reactions (vix—xvii) and hence cannot be described by kinetic parameters which take into account only these reactions. For example. Furrow (/28) has i own that caibon dioxide will react with growing polyethylene chains in a free-radical reaction, but that it terminates the chains giving carboxylic acids. It does not copolymerize in the usual sense (which would give polyesters). Carbon monoxide and sulfur dioxide appear not to obey the normal cppol3nner curve of feed composition versus polymer composition and it has been reported that these materials form a complex with ethylene whidi is more reactive than free CO or SOg, perhaps a 1 1 complex. Copolymerization of both CO and SO is further complicated by a ceiling temperature effect. Cppolymerization has been carried out with ethylene and these monomers, however, and poly-ketones and pol3Tsufones are the resultant products. 

Whdi ethylene is copolymerized with propylene, the amorphous, rubbery material called ethylene propylene rubber PM - from ethylene propylene monomers) results if the ethylene content is high commercial polymers may contain 30 to 50% of ethylene units. In order to obtain a sulfur vul-canisable material, a small percentage of a third monomer (3 to 10% of a diene monomer, for example, ethylidene nor-bornene) is incorporated so as to make a terpolymer, this ter-polymer may be referred to as EPDM. An abbreviation which covers both types of ethylene propylene rubber is EP(D)M usually, all types of this rubber have a propylene content of between 25 and 55% by weight. 

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