Polyepichlorohydrin

With one oxygen atom, one methine carbon atom with a chloromethylene substituent, and a methylene carbon atom. Because the methine carbon atom has four different substituents, i.e., O, CH3, CH2 and CH2CI, the monomer exists in both R and S configurations and can be resolved into pure stereoisomers [6]. 

This 2D-NMR method is capable of analysing PECH to ascertain its regiosequence distribution. It consists of taking its heteroonuclear chemical shift correlation spectroscopy (THCSC) spectrum, integrating the peaks corresponding to the 

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In 1957, it was discovered that organometaUic catalysts gave high mol wt polymers from epoxides (3). The commercially important, largely amorphous polyether elastomers developed as a result of this early work are polyepichlorohydrin (ECH) (4,5), ECH—ethylene oxide (EO) copolymer (6), ECH—aUyl glycidyl ether (AGE) copolymer (7,8), ECH—EO—AGE terpolymer (8), ECH—propylene oxide (PO)—AGE terpolymer (8,9), and PO—AGE copolymer (10,11). The American Society for Testing and Materials (ASTM) has designated these polymers as follows ... 

Epichlorohydrin Elastomers without AGE. ECH homopolymer, polyepichlorohydrin [24969-06-0] (1), and ECH—EO copolymer, poly(epichlorohydrin- (9-ethylene oxide) [24969-10-6] (2), are linear and amorphous. Because it is unsymmetrical, ECH monomer can polymerize in the head-to-head, tail-to-tail, or head-to-tail fashion. The commercial polymer is 97—99% head-to-tail, and has been shown to be stereorandom and atactic (15—17). Only low degrees of crystallinity are present in commercial ECH homopolymers the amorphous product is preferred. 

Although these curative systems may also be used with the polyepichlorohydrin elastomers containing AGE, the polymers were developed to be cured with conventional mbber curatives, sulfur, and peroxides. These polymers containing the pendent aHyl group are readily cured with a typical sulfur cure system such as zinc oxide, and sulfur along with the activators, tetramethylthiuram mono sulfide [97-74-5] (TMTM) and... 

Vulcanisation can be effected by diamines, polyamines and lead compounds such as lead oxides and basic lead phosphite. The homopolymer vulcanisate is similar to butyl rubber in such characteristics as low air permeability, low resilience, excellent ozone resistance, good heat resistance and good weathering resistance. In addition the polyepichlorohydrins have good flame resistance. The copolymers have more resilience and lower brittle points but air impermeability and oil resistance are not so good. The inclusion of allyl glycidyl ether in the polymerisation recipe produces a sulphur-curable elastomer primarily of interest because of its better resistance to sour gas than conventional epichlorhydrin rubbers. 

Polyisobutylene rubber Butyl rubber Halobutyl rubber Polyepichlorohydrin Polypropylene Polypropylene oxide... 

Polyepichlorohydrin (PECH) is well known as a reactive elastomer. Displacement at the carbon-chlorine bond of PECH has been accomplished with a wide variety of nucleophilic reagents, for the purposes of polymer modification, grafting and crosslinking (1, 2). On the other hand, the PECH structure (1) is hardly optimal from the point of view of its reactivity as a substrate for nucleophilic... 

These results suggest that poly[(chloromethyl)thiirane] (PCMT, 4) should be substantially more reactive than polyepichlorohydrin... 

Polyepichlorohydrin and dimethylamine Polymerisation of epichlorohydrin in carbon tetrachloride with boron trifluoride/ether catalyst, then reaction with dimethylamine. Applied to cotton by exhaust method or pad-dry. Scheme 10.65 Good yields with direct dyes using only 2 g/l salt. Excellent build-up with most reactive dyes only 10% of normal salt usage needed for low-reactivity dyes and none for highly reactive types. Washing fastness very good but light fastness impaired. 

Table II summarized the ratios of major absorbances of HTE liquid polymers. Only the ratio of hydroxyl absorbance is sensitive to the molecular weight, whereas the other two ratios are independent of it. For comparison, the ratios of absorbances of high molecular weight elastomers (Hydrin 100) made by a coordination catalyst (R3AI/H2O) are also shown in Table II. No hydroxyl absorbance is detected. The two ratios of CH/CO and CC1/C0 absorbances of HTE liquid polymers match well with those of elastomers and are characteristic feature of polyepichlorohydrin.

The complicated pattern for the methylene carbon of the polymers indicates the presence of an irregular structure of head to head and tail to tail linkages. On the other hand, the uniformly head to tail structure of polyepichlorohydrin elastomers made by the coordination catalyst shows a doublet for the methylene carbon at 70.2 and 70.0 ppm (21). No peak corresponding to the terminal methine or chloromethyl carbons is detected in elastomers. 

The PA-300 membrane was commercially developed by Riley and coworkers (15), and is similar to the NS-101 membrane in structure and fabrication method. The principal difference is the substitution of a polyetheramlne, the adduct of polyepichlorohydrin with 1,2-ethanediamine, in place of polyethylenlmine. Use of the polyetheramlne was significant improvement in that considerably higher membrane fluxes were possible at salt rejections equivalent to the NS-lOO membrane system. The actual barrier layer in the PA-300 membrane is a polyamide formed by Interfaclal reaction of Isophthaloyl chloride with the polyetheramlne. 

GAP is synthesized by replacing C-Cl bonds of polyepichlorohydrin with C-N3 bonds.The three nitrogen atoms of the N3 moiety are attached linearly with ionic and covalent bonds in every GAP monomer unit, as shown in Fig. 4.6. The bond energy of N3 is reported to be 378 kj mol per azide group. Since GAP is a liquid at room temperature, it is polymerized by allowing the terminal -OH groups to react with hexamethylene diisocyanate (HMDl) so as to formulate GAP copolymer, as shown in Fig. 4.7, and crosslinked with trimethylolpropane (TMP) as shown in Fig. 4.8. The physicochemical properhes of GAP prepolymer and GAP copolymer are shown in Table 4.4 and Table 4.5, respectively.I ]... 

Polyepichlorohydrin and copolymers and terpolymers of epichlorohydrin with ethylene oxide and allyl glycidyl ether are useful elastomers [Body and Kyllinstad, 1986]. 

The poly(ether/amide) thin film composite membrane (PA-100) was developed by Riley et al., and is similar to the NS-101 membranes in structure and fabrication method 101 102). The membrane was prepared by depositing a thin layer of an aqueous solution of the adduct of polyepichlorohydrin with ethylenediamine, in place of an aqueous polyethyleneimine solution on the finely porous surface of a polysulfone support membrane and subsequently contacting the poly(ether/amide) layer with a water immiscible solution of isophthaloyl chloride. Water fluxes of 1400 16001/m2 xday and salt rejection greater than 98% have been attained with a 0.5% sodium chloride feed at an applied pressure of 28 kg/cm2. Limitations of this membrane include its poor chemical stability, temperature limitations, and associated flux decline due to compaction. 

VC/Polyepichlorohydrin and VC/Poly (epichlorohydrin-co-ethylene oxide) Graft Copolymers. Graft copolymers of this type with high backbone-polymer content should be useful PVC additives. 

VC/Polyepichlorohydrin and VC/Poly(epichlorohydrin-co-ethylene oxide) Graft Copolymers. Alloys of PVC and graft copolymers of this type with high backbone-polymer content give interesting results in the field of bottle blowing (12). The combination of transparency and impact strength that can be realized with these compositions should enable them to penetrate into the field covered at present by PVC-MBS mixtures. 

Sequence distribution studies on several types of rubber by 13C-NMR technique have been reported. Some of the more recent reports include silicone rubbers [28-30], SBR [31], acrylonitrile-butadiene rubber (NBR) [32,33], polyurethane [34,35], polyepichlorohydrin [36], ethylene-norbonene [37] and ethylene-propylene rubber [4, 16, 25, 38-44]. The NMR studies on EPDM have been carried out extensively, because it is one of the important parameters, which control the physical properties of the elastomer. For example, ethylene sequence can influence the crystallisation kinetic and melting behaviour of the rubber [38]. 

FIGURE 9.17 Dependence of productivity and separation factor /3p C6H5CH3/H2O of membranes based on various rubbery polymers on the glass transition temperature of the polymer (pervaporation separation of saturated toluene/water mixture, T = 308 K) (1) polydimethyl siloxane (2) polybutadiene (3) polyoctylmethyl siloxane (4) nitrile butadiene rubber with 18% mol of nitrile groups (5) the same, 28% mol of nitrile groups (6) the same, 38% mol of nitrile groups (7) ethylene/propylene copolymer (8) polyepichlorohydrin (9) polychloroprene (10) pol3furethane (11) polyacrylate rubber (12) fluorocarbon elastomer. (From analysis of data presented in Semenova, S.I., J. Membr. Sci., 231, 189, 2004. With permission.)... 

A number of chlorinated poly(ethers) have practical uses. A common compound from this group is polyepichlorohydrin, [-CH(CH2CI)CH20-]n. Polyepichlorohydrin has practical applications as an elastomer and is used in copolymers with propylene oxide, ethylene oxide, allyl glycidyl ether (1-allyloxy-2,3-epoxypropane), etc. Another example is poly oxy[2,2 -bis(chloromethyl)-1,3-propandiyl] or poly[oxy-1,3-(2,2 -dichloromethyl)propylene], CAS 25323-58-4, which can be used as inert lining material for chemical plant equipment, as adhesive, coating material, etc. This macromolecule can be prepared starting with pentaerythritol in the sequence of reactions shown below ... 

Figure 9.1.18. Result for a Py-GC/MS analysis of polyepichlorohydrin M = 700,000. Pyrolysis done on 0.4 mg material at 60CP C. with the separation on a Carbowax type column.

Table 9.1.13. Compounds identified in the pyrogram of polyepichlorohydrin M 700,000 as shown in Figure 9.1.18.

Polyepichlorohydrin pyrolysate is a complex mixture of compounds, somehow similar to that obtained by the pyrolysis of poly(ethylene oxide). The breaking of the C-O bonds is probably easier than that of C-C bonds. However, C-C bonds are more frequently cleaved in pyrolysis of polyepichlorohydrin than in that of poly(propylene oxide). The elimination of HCI (4.7% in the pyrogram) further complicates the pyrogram of this polymer. 

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