Latices, terpolymer

The most common textile bonding compositions are, of course, the RFL (resorcinol-formaldehyde-latex) dips used to adhere tire carcass rubber to cord reinforcing members. A typical RFL composition calls for a latex terpolymer of styrene-butadiene-vinyl pyridine as well as the resorcinol and hexamethylene tetramine. Some natural rubber latex or regular SBR latex may also be added. The R F resin which forms in situ is able to react chemically with rayon by methylol etherification of the cellulose s hydroxyls. Similar reaction is likely with the amide groups of nylon fibers as shown in Figure 7. 

At the elastomer end, it is reasonable to draw a closer analogy with rubber-to-metal bonding agents. The RLF s latex terpolymer is a diene rubber, and is likely to be vulcanized by any sulfur or accelerators that diffuse over from the carcass rubber. It has further been conjectured that the pendant pyridine rings of the same terpolymer should be attacked by the reactive R-F species. Thus, a total chemical network, but involving two or more kinds of cross-linking or covalent bonding reactions, is plausible. ... 

Vinylpyridine (23) came into prominence around 1950 as a component of latex. Butadiene and styrene monomers were used with (23) to make a terpolymer that bonded fabric cords to the mbber matrix of automobile tires (25). More recendy, the abiUty of (23) to act as a Michael acceptor has been exploited in a synthesis of 4-dimethylaminopyridine (DMAP) (24) (26). The sequence consists of a Michael addition of (23) to 4-cyanopyridine (15), replacement of the 4-cyano substituent by dimethylamine (taking advantage of the activation of the cyano group by quatemization of the pyridine ring), and base-cataly2ed dequatemization (retro Michael addition). 4-r)imethyl aminopyri dine is one of the most effective acylation catalysts known (27). 

One component of a terpolymer of butadiene, styrene and vinyl pyridine used in latex form to promote good adhesion between rubber and textiles, particularly rayon and nylon. Viscoelasticity... 

The polymerization of a mixture of more than one monomer leads to copolymers if two monomers are involved and to terpolymers in the case of three monomers. At low conversions, the composition of the polymer that forms from just two monomers depends on the reactivity of the free radical formed from one monomer toward the other monomer or the free radical chain of the second monomer as well as toward its own monomer and its free radical chain. As the process continues, the monomer composition changes continually and the nature of the monomer distribution in the polymer chains changes. It is beyond the scope of this laboratory manual to discuss the complexity of reactivity ratios in copolymerization. It should be pointed out that the formation of terpolymers is even more complex from the theoretical standpoint. This does not mean that such terpolymers cannot be prepared and applied to practical situations. In fact, Experiment 5 is an example of the preparation of a terpolymer latex that has been suggested for use as an exterior protective coating. 

Vinylpyridine is used in the terpolymer latex component of tire cord dips to improve the bonding of textile to rubber. Rubber hres built with steel cord, however, do not require vinylpyridine latex-based adhesives for the steel belt, Therefore, the consumption of vinylpvridines may be affected in the future,... 

Commercial ABS is prepared primarily by free-radical emulsion copolymerization of styrene and acrylonitrile in the presence of polybutadiene latex (3). This method was therefore adapted for the preparation of ABS and MBS terpolymers and an intermediate AMBS tetrapolymer under similar conditions (Table I). Polymerizations were charged into 12-ounce crown-cap bottles, sparged and flushed with nitrogen, and... 

The author notes that his results are consistent with those of Stam-berger (27) who worked with a styrene-ethyl hexyl acrylate-acrylic acid emulsion terpolymer. At pH 8, the emulsion was stable to liquid shear, whereas at pH 3, it was unstable. There was little difference in zeta potential of the latex at the two pH values. 

Terpolymer Resins. DBPF was dissolved in a mixture of styrene, acrylonitrile, and mercaptan (Table I). About one-tenth of this solution was added to a solution of sodium alkylbenzene sulfonate emulsifier (Nacconal NRSF, 2 parts) in deionized water (180 parts) at 60°C. Potassium persulfate (0.3 part) was added, followed by the remaining monomer mixture at a rate consistent with temperature control (60°C.) Gentle agitation and a nitrogen atmosphere were maintained throughout the polymerization. The latex was maintained at 60 °C. until a solids determination indicated no further conversion (6—8 hours total polymerization time). 

Copolymers 59 [181] and terpolymers 60 [182] were synthesized by micellar copolymerization and characterized with respect to their molecular and solution properties. The subject of further investigations was the interaction with low molecular weight surfactants [181,183]. Another interesting use was made of hydrophobized sulfopropylammonio monomers as surface-active monomers (or surfmers ) [184]. Their use in emulsifler-free emulsion polymerizations [185] reduced the water uptake and improved the mechanical stability of the resulting filmed latexes. 

Styrene is frequently used as part of some terpolymers with large practical utilization. One such copolymer is acrylonitrile-butadiene-styrene terpolymer (ABS). Usually it is made as poly(l-butenylene-graft-l-phenylethylene-co-cyanoethylene). This form of the copolymer can be made by grafting styrene and acrylonitrile directly on to the polybutadiene latex in a batch or continuous emulsion polymerization process. Grafting is achieved by the free-radical copolymerization of styrene and acrylonitrile monomers in the presence of polybutadiene. The degree of grafting is a function of the 1,2-vinyl content of the polybutadiene, monomer concentration, extent of conversion, temperature and mercaptan concentration (used for crosslinking). The emulsion polymerization process involves two steps production of a rubber latex and subsequent polymerization of styrene and acrylonitrile in the presence of the rubber latex to produce an ABS latex. 

This latex is then processed to isolate the ABS resin, ABS thermoplastic combines good mechanical properties and heat resistance. It is used in many household appliances, automotive parts, furniture, etc. Another similar terpolymer is acrylonitrile-styrene-acrylate (ASA). It is used in automobile industry, in house construction, household appliances, etc. 

As previously mentioned, the properties of olefm-CO copolymers depend strongly on the nature of the olefin employed. The glass transition temperature of 1-olefin-CO copolymers decreases from room temperature to nearly -60 °C upon increasing the chain length of the 1-olefin from propylene to 1-dodecene [33]. By contrast to polar ethylene-CO copolymers, copolymers with higher l-olefins display a hydrophobic character. For 1-olefin copolymerization, catalysts with entirely alkyl-substituted diphosphine hgands R2P-(CH2) -PR2 (R=alkyl, by comparison to R=Ph in dppp) such as 3 are particularly well-suited [48]. Efhylene-l-olefin-CO terpolymers and 1-olefin-CO copolymers can be prepared in aqueous polymerizations [43, 47, 48]. In the aforementioned copolymerization reactions, the polyketone was reported to precipitate during the reaction as a sohd [45, 47, 48, 50]. However, in the presence of an emulsifier such as sodium dodecyl sulfate (SDS) and under otherwise suitable conditions, stable polymer latexes can be obtained. 

Pentachlorophenyl acrylate, (1), was terpolymerized with methyl methacrylate (MMA) and n-butyl acrylate (nBA) (Scheme III) to give a latex containing 537 solids and a pll of 4.7 which was adjusted to 6.8 by adding aqueous NaOH. The latex was stable up to pH =10. A small aliquot vzas coagulated and the resulting polymer purified. Its intrinsic viscosity was 3.1 /g and analysis indicated 2 mole percent (1), 587 CIA and 40" nBA. Similar terpolyner latices were prepared from acrylates (2) and (3) (Scheme III). Another terpolymer latex made from (3), vinyl acetate, and 2-ethylhexyl acrylate contained 547 solids. Tliese latices and their compositions are summarized in the Table 1 and a sample experimental procedure is given in the experimental section. 

Attempts to make acrylic latlces containing o-benzyl-p-chlorophenyl acrylate, 17, using the same techniques employed for the systems In Table 6, failed. It was found that no 17 was Incorporated Into the polymer of these latlces. Similar attempts to make terpolymer latlces with vinyl pentachlorophenyl ether, 25 or vinyl 3,4 5-trlbromosallcylanlllde ether, 28 (with MMA and nBA) failed. These fungicidal vinyl ethers were not.Incorporated Into the resulting latex polymers. However, vinyl o-benzyl-p-chlorophenyl ether, 17, was successfully terpolymerized In latex form (see latex 12, Table 6). Formulations for latlces 1-3 and 5-14 are given In Table 7. 

A standard Paint Research Institute latex paint, provided by J. F. Matthews of DuPont, was the reference sample to which the biocidal latex polymers were compared. After two months both the unweathered and weathered samples showed moderate or moderate to heavy growth on the paint surface. The unweathered samples showed severe stain intensities on basswood. The weathered samples showed medium stain intensities on both. When coatings of an MMA/nBA latex blended with a MMA/nBA/8 terpolymer latex were tested, only trace growth of Aureobasidlum pullulans on the coatings was observed using pine or basswood substrates. 

During the course of these studies, a large number of copolymer, terpolymer, and latex samples containing chemically bound biocides were given to the Mildew Steering Committee. 

Pyridine bases namely 2 4-picolines are important commodity chemicals which are used in pharmaceuticals, rubber eind agricultural industries. 2-picoline is consumed for several different pesticides, and is used in the production of 2-vinylpyridine, which is a component of styrene-butadiene-vinylpyridine terpolymer latexes. The major outlet for 4-picoline is for the manufacture of 4-vinylpyridine and INH an anti-tubercular drug. The stringent specifications laid down for these products in pharmaceutical and agricultural applications can not be met from natural sources namely from coal carbonisation byproducts. Synthetic pyridine is the only answer to this problem. 

The largest use of a-picoline (2) is for production of 2-vinylpyridine (11) which, with butadiene and styrene, is converted into a terpolymer latex. This latex provides a coating that stiffens fabrics (e. g. nylon, polyester, rayon) that are incorporated into biased-ply car tires. The 2-vinylpyridinc assists in binding the rubber to the fabric carcass. a-Picoline is also used as a precursor to nitrapyrin (12), which prevents nitrogen loss from soil, and the herbicide picloram (13). 

Beiistein Handbook Reference) AI3-08621 BRN 0507434 EINECS 203-674-6 1,3-Dibutylthiourea 1,3-Di-n-butyl-2-thiourea 1,3-Dibutyl-2-thiourea NSC 3735 Pennzone B Pennzone B 0685 Thiate U Thiourea, N,N -dibutyl- Urea, 1,3-dibutyl-2-thio- Urea, 1,3-di-N-butyl-2-thio- USAF EK-2138. Accelerator for mercaptan-modified chlotoprene rubber, an activator for ethylenepropylenediene terpolymers and natural nibber, an antidegradant for natural rubber-latex and thermoplastic styrene-butadiene rubber. Crystals mp = 63-65°. ElfAtochem N. Am. 

One of the most important bulk property variables of polymers is the glass transition temperature 7g, which must be well below the use temperature to allow the interdiffusion and entanglement of polymer chains when the particles get in contact, once the aqueous phase has been evaporated. Thus, the monomer(s) used have to be selected such that the desired is obtained. Useful tables showing Tg and other physical and chemical properties of homopolymers are available in the literature [66-68]. The well-known Fox equation [69] can be used to estimate the Tg of a copolymer as a function of monomer composition and TgS of the component monomers. It is important to take into account that polar polymers tend to hydroplasticize, reducing the in the film formation process [70]. Several commercial latexes are terpolymers that contain two of the monomers present in major amounts to grossly obtain the basic desired properties, with the third monomer present in a minor amount for fine tuning of a special property [71-73]. 

HIPS) is produced commercially by the emulsion polymerization of styrene monomer containing dispersed particles of polybutadiene or styrene-butadiene (SBR) latex. The resulting product consists of a glassy polystyrene matrix in which small domains of polybutadiene are dispersed. The impact strength of HIPS depends on the size, concentration, and distribution of the polybutadiene particles. It is influenced by the stereochemistry of polybutadiene, with low vinyl contents and 36% d5-l,4-polybutadiene providing optimal properties. Copolymers of styrene and maleic anhydride exhibit improved heat distortion temperature, while its copolymer with acrylonitrile, SAN — typically 76% styrene, 24% acrylonitrile — shows enhanced strength and chemical resistance. The improvement in the properties of polystyrene in the form of acrylonitrile-butadiene-styrene terpolymer (ABS) is discussed in Section VILA. 

In an examination of the shear behaviour of latexes in which the particles were carboxylated terpolymers of styrene, butyl acrylate and ethyl acrylate Husband and Adams [94] found that shear coagulation was sensitive to pH. Their results are illustrated in Figure 3.29. Both the latexes used swelled with increase of pH... 

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