Styrene acrylonitrile , composite

A. J. Yu and R. E. Gallagher, Acrylate-Styrene-Acrylonitrile Composition and Method of Making the Same, U.S. Pat. 3,944, 631 (1976). Latex IPN of acrylate elastomer/styrene-acrylonitrile. Latex IPN embedded in linear styrene-acrylonitrile. Rubber-toughened, impact-resistant plastics. 

Styrene-Acrylonitrile (SAN) Copolymers. SAN resins are random, amorphous copolymers whose properties vary with molecular weight and copolymer composition. An increase in molecular weight or in acrylonitrile content generally enhances the physical properties of the copolymer but at some loss in ease of processing and with a slight increase in polymer color. 

Not only ate ABS polymers useful engineering plastics, but some of the high mbber compositions are excellent impact modifiers for poly(vinyl chloride) (PVC). Styrene—acrylonitrile-grafted butadiene mbbers have been used as modifiers for PVC since 1957 (87). 

Fig. 24. Relationship between feed composition and copolymer composition of styrene—acrylonitrile copolymerization. See text.

The authors of [317] investigated compositions based on PS, PMMA and styrene-acrylonitrile copolymer grafted to various fillers and found that it was possible, in this manner, to obtain particles with a grafted polymeric coating of sufficiently homogeneous thickness. 

Determine the copolymer composition for a styrene-acrylonitrile copolymer made at the azeotrope (62 mol% styrene). Assume = 1000. One approach is to use the Gaussian approximation to the binomial distribution. Another is to synthesize 100,000 or so molecules using a random number generator and to sort them by composition. 

Suppose the reactor sized in Problem 13.14 is converted to manufacture a styrene-acrylonitrile copolymer containing 36% acrylonitrile by weight. Assume 50% conversion as before. What is the required feed composition to the reactor and what is the composition of the unreacted monomer mixture ... 

This method involves the mechanical blending of styrene-acrylonitrile copolymers and acrylonitrile-butadiene rubbers. Many products are possible depending on the composition of each copolymer and the relative amounts employed. 

Fig. 56. Dependence of specific refractive index increment on conversion of monomers to polymer for a styrene/acrylonitrile/methyl methacrylate terpolymer in methyl ethyl ketone at 20 °C and 436 nm. (a) - partial azeotrope, (b) terpolymer with composition distribution163 ...

The sequence distributions expected for the different models have been described [Hill et al., 1982, 1983 Howell et al., 1970 Tirrell, 1986] (Sec. 6-5a). Sequence distributions obtained by 13C NMR are sometimes more useful than composition data for discriminating between different copolymerization models. For example, while composition data for the radical copolymerization of styrene-acrylonitrile are consistent with either the penultimate or complex participation model, sequence distributions show the penultimate model to give the best fit. 

An appropriate formalism for Mark-Houwink-Sakurada (M-H-S) equations for copolymers and higher multispecies polymers has been developed, with specific equations for copolymers and terpolymers created by addition across single double bonds in the respective monomers. These relate intrinsic viscosity to both polymer MW and composition. Experimentally determined intrinsic viscosities were obtained for poly(styrene-acrylonitrile) in three solvents, DMF, THF, and MEK, and for poly(styrene-maleic anhydride-methyl methacrylate) in MEK as a function of MW and composition, where SEC/LALLS was used for MW characterization. Results demonstrate both the validity of the generalized equations for these systems and the limitations of the specific (numerical) expressions in particular solvents. 

Figure 5.99 Relationship of glass fiber content with (a) tensile strength and (b) flexural modulus for styrene acrylonitrile (SAN) and polypropylene (PP). Reprinted, by permission, from G. Lubin, Handbook of Fiberglass and Advanced Plastics Composites, p. 130. Copyright 1969 by Van Nostrand Reinhold.

M. Fowler, J. Barlow, and D. Paul, Effect of copolymer composition on the miscibility of blends of styrene-acrylonitrile copolymers with poly (methyl methacrylate), Polymer, 28(7) 1177-1184, June 1987. 

A typical unsaturated unreinforced polyester resin has an extremely low notched Izod impact strength. The addition of fibrous glass can change this extremely brittle material into a high impact strength composite. The same phenomenon occurs with some brittle thermoplastics, such as polystyrene and styrene—acrylonitrile. 

The particles have a relatively uniform density of about 0.95 g cm-3 and hence a content of poly(butadiene) of 59 percent (ratio of the weight styrene/ acrylonitrile = 88/12). With this gradient system the investigation of the chemical composition and heterogeneity of nearly all butadiene copolymer latices is possible. The experiment needs about 1 hour. 

We will describe its use for controlling the styrene-acrylonitrile emulsion copolymerization system. Results concerning copolymer compositions, molecular characteristics and particle sizes will be compared to the corresponding ones from batch or semi-continuous processes. 

Conventional ABS polymers are blends of poly (styrene-coacrylonitrile) with either poly (butadiene-coacrylonitrile) or a graft of poly-(styrene-coacrylonitrile) onto a rubbery spine. To confer flame-resistance on either ABS system using DBPF as a fourth monomer, the major component should be a styrene-acrylonitrile-DBPF terpolymer since the resinous component is the major one. The composition of such a terpolymer is restricted by two considerations (1) it should contain sufficient acrylonitrile to impart the resistance to solvent attack which is characteristic of ABS polymers, and (2) the amount of DBPF should be sufficient to give a useful level of flame resistance. 

Fig. 22a-h. Glass transition temperature versus composition of copolymers methyl methacrylate + styrene (a) styrene + methyl acrylate (b) acrylonitrile + styrene (c) vinyl chloride + methyl acrylate (d) methyl methacrylate + vinyl chloride (e) acrylonitrile + butadiene (f) acrylonitrile + vinyl acetate (g) a-methyl styrene + acrylonitrile (h). Experimental points obtained at low conversions from various publications, are compared to the theoretical plots calculated according to Eqs. (7.1) within the framework of the terminal model [18]... 

A first indication of the composition of the present sample was obtained from the contour plot in Fig. 32. Component 3 shows typical absorption peaks of a phenyl benzotriazole and can be identified as a UV stabilizer of the Tinuvin type. Component 2 exhibits absorption peaks which are characteristic for nitrile groups (2237 cm x) and styrene units (760,699 cm-1), while component 1 shows a strong ester carbonyl peak around 1740 cm"1 and peaks of styrene units. In agreement with the peak pattern of literature spectra, component 2 can be identified as a styrene-acrylonitrile copolymer. Component 1 is either a mixture of... 

Fig. 1. Approximate compositions of styrene—acrylonitrile copolymers formed at different conversions starting witli various monomer mixtures (35) ...

Gloeckner G, Wolf D and Engelhardt H (1991) Separation of copoly(styrene/ acrylonitrile) samples according to composition under reversed phase conditions. Chromatographia 32 107-12. 

Warakomski, J and Dion R (1992) The effect of chemical composition on the miscibility of styrene/acrylonitrile/fumaronitrile terpolymers with styrene/acryloni-trile copolymers. J Appl Polym Sci 46 1057-63. 

In general, an alternating eopolymer is formed over a wide range of monomer compositions. It has been reported that little chain transfer occurs, and in some cases, conventional free radical retarders are ineffective. Reaction occurs with some combinations, like styrene-acrylonitrile, when the monomers are mixed with a Lewis acid, but addition of a free-radical source will increase the rate of polymerization without changing the alternating nature of the copolymer. Alternating copolymerizations can also be initialed photochemically and electrochemically. The copolymerization is often accompanied by a cationic polymerization of the donor monomer. 

---