Syndiotactic polystyrene blends

Liao X, Nawaby AV, Handa YP (2007) Layered and cellular morphologies in atac-tic/syndiotactic polystyrene blends. Cell Polym 26 69-81... 

Chen, B., Tang, T, Xu, S., Zhang, X., Huang, B. Compatibilization of polyam-ide-6/syndiotactic polystyrene blends using styrene/glycidyl methacrylate copolymers. Polymer Journal, 35(2), 141-147 (2003). 

Kolarik, J., Eambri, L., Sloul) M., Konecny, D. Heterogeneous polyamide 66/ syndiotactic polystyrene blends Phase structure and thermal and mechanical properties. Journal of Applied Polymer Science, 96(3), 673-684 (2005). 

Hong, B. K. and Jo, W. H. (2000) Effects of molecular weight of SEBS triblock copolymer on the morphology, impact strength, and rheological property of syndiotactic polystyrene/ ethylene-propylene rubber blends. Polymer, 41, 2069-2079. 

Xu S, Chen B, Tang T, Huang B. Syndiotactic polystyrene/thermoplastic polyurethane blends using poly(styrene-l)-4-vinylpyridine) diblock copolymer as a compatibilizer. Polymer 1999 40 3399-3406. 

Recovery of properties may be based on specific polymers and their blends (viz. syndiotactic polystyrene, polyesteretherimide, some blends of polyphenyleneether) that have been shown to maintain high performance for at least 5-10 re-extrusions. It has been also shown that properly stabilized resins (e.g., polyolefins) are able to maintain performance for at least five re-extrusions [Herbst et ah, 1997]. 

S. Stack, 0. O Donoghue, and C. Birkinshaw. The thermal stability and thermal degradation of blends of syndiotactic polystyrene and polyphenylene ether. Polym. Degrad. Stabil, 79(l) 29-36, 2003. 

Joh Johnsen, B. B., Kinloch, A. J., Taylor, A. C. Toughness of syndiotactic polystyrene/epoxy polymer blends Microstructure and toughening mechanisms. Polymer 46 (2005) 7352-7369. 

Liu and Sen ° have shown that syndiotactic polystyrene (sPS) can be partially brominated at the benzylic positions. Starting from these polymers, graft copolymers could be synthesized by ATRP using the partially brominated sPS as macroinitiator (Figure 10). They extended the strategy to PE-based graft copolymers such as poly(ethylene-co-styrene)- o/t-PMMA (P(E-co-S)-g-PMMA). This is an efficient compatibilizer for blends of poly(ethylene) and PMMA. ... 

S. Cimmino, E. D. Pace, E. Martuscelli, C. Silvestre, D. M. Rice, and F. E. Karasz, Miscibility of syndiotactic polystyrene/poly(vinyl methyl ether) blends. Polymer, Vol. 34, 214-217, 1993. 

Ho and co-workers [62] used SAXS, among other techniques, to examine microphase separation and crystallisation in a melt-mixed blend of syndiotactic polystyrene (sPS) with a block copolymer of styrene and ethylene propylene. 

Syndiotactic polystyrene (sPS) is a hard, stiff material with high temperature stability and excellent isolator properties. The E-module of ca. lO Mpa is similar to that of polyamide 66, and therefore much higher than in amorphous polystyrene. These properties lead to new, very interesting apphcations, especially Lf sPS is blended with polyamides [6]. 

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). 

Recyclable blends of syndiotactic polystyrene, sPS, were prepared by blending sPS with a copolymer of styrene with either maleic anhydride (MA), or with glycidyl methaciylate (GMA), and with an elastomer, e.g., SEES, SBS, SBR, EPDM. The compositions showed good impact resistance, elongation and retention of physical properties upon... 

Recent work on crystallinity measurements is reported below sulfur containing ether ketones [14], polyethylene glycol [15], polystyrene (PS) [16, 17], (PC) [18], polyphenylene alkene diyls [19, 20], isotactic polypropylene [20, 21], polyethylene [21, 22], polyimide [23], poly(2,5 bis (4-methoxyphenyl) oxycarbonyl styrene [24], polyazomethine esters [25], PET-polybutylene terephthalate blends [26], polycyclohexyl ethylene copolymers [27], polycaprolactone [28], syndiotactic polystyrene [29, 30], polyvinylidene fluoride-trifluorethylene copolymer [30], polyethers [31], isotactic methyl methacrylate [32], soy protein isolate polymers [33], polyamide 6/66 [34], polytrimethylene-2,6-naphthalate [35, 36], PE like polyesters [37], polycyclohexadiene [38], p-dioxolone, L-lactide - polyethylene glycol copolymers [39], ethylene - methacrylic acid copolymers and ionomers [40]. 

Blends of PPO with PS containing sulfonated and carboxylated groups have been reported in various studies [394-396]. The miscibility of sulfonated PS with PPO, sulfonated PPO with PS and blends of the sulfonated polymers was reported by Hseih and Peilfer [394]. Miscibility was maintained with sulfonation levels up to 2-4mol% for PS with sulfonated PPO and sulfonated PS with PPO. When both polymers were sulfonated, phase separation occurred at higher levels (> 10mol% sulfonation). The miscibility can be influenced by counter ion, as noted in a comparison of a Zn + neutralized sulfonic acid modified PS, which exhibited a larger miscibility window with PPO than the Na neutralized coimterpart [396]. Syndiotactic polystyrene was noted to be miscible over the entire composition range in amorphous blends with PPO, where the Tg versus composition followed the Fox equation predictions [397]. Isotactic polystyrene miscibility with PPO has also been observed, with crystallization and orientation data reported on the blend [398]. 

Poly(cyclohexyl acrylate) was shown to be miscible with PS with ucst behavior [720]. Random copolymers of cyclohexyl acrylate with n-butyl acrylate showed miscibility with PS above 50% cyclohexyl acrylate[721]. Poly(cyclohexyl methacrylate)/isotactic PS blends showed miscibility based on calorimetry and NMR studies [722]. The NMR results showed homogeneous behavior at a scale of 2.5-3.5 nm. Poly(4-trimethylsilyl styrene) miscibility with polyisoprene was observed with a lest behavior (critical temperature = 172 ° C at degree of polymerization of 370) [723]. The interaction parameter, showed the following relationship = 0.027—9.5/T. Isotactic and syndiotactic polystyrene both exhibit crystallinity, whereas atactic polystyrene is amorphous. Atactic PS/isotactic PS blends exhibited crystallization kinetics, which decreased linearly with atactic PS addition indicating miscibility [724]. The TgS of aPS and iPS are identical, thus Tg methods could not be employed to assess miscibility. Atactic PS/syndiotactic PS blends were also noted to be miscible with rejection of atactic PS in the interfibrillar region between the lamellar stacks of sPS [725]. 

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