Elastomer toughening

In multiphase polymeric systems, the properties of the end products do not solely depend on the properties of the pure components, but other various parameters also have a great impact (Fig. 1). In order to emphasize these factors, the following systems are taken into consideration (I) elastomer toughened styrene system, (2) elastomer toughened polycarbonate blends, and (3) direct reactive blend processing. 

Kumar G., Neelakantan N.R., and Subramanian N., Mechanical behaviour of polyacetal and thermoplastic polyurethane elastomer toughened polyacetal, Polym. Plastics TechnoL Eng., 32, 33, 1993. Newmann W. et al.. Preprints, 4th Rubber Technology Conference, London, May 22-25, 1962. Farrissey W.J. and Shah T.M., Handbook of Thermoplastic Elastomers (Walker B.M. and Rader C.P., eds.). Van Nostrand Reinhold, New York, 1988. 

Block copolymers possess unique and novel properties for industrial applications. During the past 20 years, they have sparked much interest, and several of them have been commercialized and are available on the market. The most common uses of block copolymers are as thermoplastic elastomers, toughened thermoplastic resins, membranes, polymer blends, and surfactants. From a chemist s point of view, the most important advantage of block copolymers is the wide variability of their chemical structure. By choice of the repeating unit and the length and structure of both polymer blocks, a whole range of properties can be adjusted. 

T300/CE339 Ferro Corp LaRC2 121°C cure 2-phase elastomer toughened epoxy... 

Figure 24. Effect of radiation fluence on thermal expansion of elastomer-toughened specimens during cool down from room temperature. (Reproduced from reference 19.)...

Poomalai, R, Varghese, T. O., and Siddaramaiah. 2008. Investigation on thermoplastic CO poly (ether-ester) elastomer toughened poly (methyl methacrylate) blends. Journal of Applied Polymer Science 109(6) 3511-3518. 

R.S. Drake, "Elastomer Toughened Epoxy Resins for Structural Adhesives, 4th Annual Meeting, The Adhesion Society, Savannah, GA (2/22/1981). 

R.Y. Ting and R.J. Moulton, "Fracture Properties of Elastomer-Toughened Epoxies," 12th National SAMPE Tech. Conf., 265, 10/7-9/1980. 

D-B transition temperature, and the effect of elastomer MFI on the D-B transitirMi temperature becomes less prominent with the increased PP molecular weight as seen in Fig. 17.18. The nanocomposites based on the high-octene-content elastomer ( 39 wt%) also lead to a lower D-B transition temperature compared with nanocomposites based on the elastomer with low octene content ( 28 wt%). The toughening mechanism was not explored for this system a more detailed study in this area would further enhance the understanding of the role of organoclay in elastomer-toughened nanocomposites with partially exfoliated clay particles. 

J. Brus, M. Urbanova, I. Kelnar, J. Kotek, A sohd-state NMR study ofstmcture and segmental dynamics of semicrystalline elastomer-toughened nanocomposites. Macromolecules 39 (2006) 5400-5409. 

A limitation of DVS-bisBCB polymer is its restriction in building thick (>S0 pm) stacks because of its modmte fracture toughness. The ductility of DVS-bisBCB polymer is significantly enhanced by the addition of an elastomer. Elastomer-toughened thermosets and thermoplastics are widely used in many diverse industries. Recent advances in this area can be found in diree American Chemical Society Symposium Series (20-22). 

Sivaraman, R, et ai. Thermoplastic copolyether ester elastomer toughened polycarbonate blends 2. Thermal and rheological studies. Polymer Tesfm, 23(6) p. 645. 2004. 

Epoxies have been toughened with elastomer-dispersed phases with a decrease in modulus. Work by Balakrishnan et al. [35] utilized organo-montmorillonite as a dispersed phase in elastomer-toughened epoxies to recover this lost modulus. The montmorillonite was modified with octadecyl ammonium ion. The elastomer-dispersed phase in the epoxy was prepared by free radical polymerization of acrylic monomer within the epoxy. The acrylic elastomer-dispersed phase had epoxy functionality provided through the utilization of glycidyl methacrylate as a comonomer. 

The composite that contained 16 phr of elastomer and 5.5 wt.% of organomontmorillonite provided unexpected results. The Young s modulus recovered modestly when the montmorillonite was in the formula. The unexpected result was the increase of percent elongation to failure from 10.0% for the elastomer toughened epoxy to 11.5% when the montmorillonite was present. 

Stress whitening (indicating cavitation during stress) for the montmorillonite containing elastomer-toughened epoxy was much more extensive that the stress whitening with the elastomer-toughened epoxy without montmorillonite. This unusual behavior will be discussed in Chapter 7 with the review of montmorillonite-elastomer nanocomposites and an unusual amorphous polyester nanocomposite, terephthal-ate copolyester prepared with 2,2,4,4-tetramethyl-l,3-cyclobutanediol and propanediol. 

Reactive Extrusion Processing of Elastomer Toughened Polyphenylene Sulfide. 

Polyphenylensulfide (PPS) features excellent mechanical properties, thermal stability, chemical resistance, flame resistance and precise moldability. However, PPS has a weak point of being a very brittie material. For use as electrical and electronic parts, automobile and mechanical parts, toughened PPS is desired. For these application, improving the toughness of PPS and developing an elastomer toughened PPS and related compounds are desired. 

Using MDA-treated PPS and an olefinic elastomer with a functional group of maleic anhydride, elastomer toughened PPS using the reactive processing method was developed. 

Though the notched izod impact strength of the original PPS is about 1 kg-cm/cm, the elastomer toughened PPS has a notched izod impact strength around 50 kg-cm/cm. 

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