High-impact SPS

Name Trade name Grades/manufacturer Relative advantages high impact very good dimensional stability passes automotive specification (Renault) Moplen SP 98 F Himont... 

Nanocomposites of syndiotactic polystyrene (sPS) employing MMT-hexadecyltributylphosphonium [40, 41] and high-impact polystyrene (H1PS)/MMT-hexadecyltriphenylphosphonium [42] were prepared by melt-blending and in situ coordination-insertion polymerization. Partially exfoliated or intercalated materials were obtained in all cases, and a decrease of crystallinity of sPS was observed. However, the presence of clay did not have a strong influence on the sPS thermal transitions. Thermal decomposition of the material was slowed and mechanieal properties were improved in the presence of low organoclay content. Intercalated HIPS nanocomposites were obtained, with improved thermal and flame retardant properties compared to pure HIPS (Figure 3.8). 

High-impact polystyrene (HIPS) and SPS was melt blended with an extruder at 290°C and was injection molded at a mold temperature of 80 C to tensile bars. Figure 17.6 shows the pictures of tensile bars of HIPS, HIPS/SPS blend and acrylonitrile-butadiene-styrene copolymer (ABS) after dipping into methyl ethyl ketone (MEK) at room temperature. 

N)3CCH3NH.C0.NH.C8H 5 mw 299-20, N23-41% ctysts, sp gr 1-51, mp 162°, bp ignites above 418°. Prepd by refluxing phenylurea with excess trinitroethanol in methanol for 3 h urs (Ref 2). Its sensitivity to impact is about that, of Comp B Refs l)BeiI., not found 2)D.L.Kouba R.H.Saunders, Hercules Powder Co Progress Rept, Sept 1950, High Explosives Task A, Contract NOrd 9925 3)W.F.Sager D.V. 

Properties White crystals. Sp. gr. 1.725. M. P. 155-166°. Decomposes at 210°. Very hygroscopic. Explosives containing ammonium nitrate may be protected from moisture by suitable coating, such as oily nitro compounds, or by selection of waterproof material for cartridges (paraffin). It is a high explosive, very insensitive to impact and difficult to detonate, requiring a combination of an initiator and a high explosive (reinforced detonators). 

---