Styrenic copolymers, functional grafting

In addition to providing fully alkyl/aryl-substituted polyphosphasenes, the versatility of the process in Figure 2 has allowed the preparation of various functionalized polymers and copolymers. Thus the monomer (10) can be derivatized via deprotonation—substitution, when a P-methyl (or P—CH2—) group is present, to provide new phosphoranimines some of which, in turn, serve as precursors to new polymers (64). In the same vein, polymers containing a P—CH group, for example, poly(methylphenylphosphazene), can also be derivatized by deprotonation—substitution reactions without chain scission. This has produced a number of functionalized polymers (64,71—73), including water-soluble carboxylate salts (11), as well as graft copolymers with styrene (74) and with dimethylsiloxane (12) (75). 

Block copolymers such as styrene-butadiene-styrene (SBS) and its hydrogenated versions (SEBS), along with polyester-polyether block copolymers, can also be used to improve PBT impact. The SEBS and SBS copolymers [47], and especially their functionalized, grafted derivatives [48], show surprisingly good affinity for the polyester. 

Me, Ph, CjH FeCp) A series of fluorinated alcohol derivatives were also prepared.The addition of (Me2SiO)3 followed by Me3SiCl or further addition of cyclosiloxane gives slloxane or poly (slloxane) substituents. The addition of CO2 to the lithiated intermediate gives a carboxylate function which can be converted to the free acid or esterifled with p-nitrobenzylbromide. The addition of styrene to [NP(CH2Li)Ph] causes anonic polymerization of styrene and thus the formation of poly(methylphenylphosphazene)-graft-polystyrene copolymers. 

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. 

PA/PO blends have been compatibihzed through graft copolymer formation between polyamide amine end-groups and pendent anhydride groups on a functionalized styrene copolymer. Also, in one example [Lu et al, 1995] this ternary blend is compatibihzed through copolymer formation between PA and anhydride-functionalized polyolefin (Table 5.14). 

Immiscible blends of PA and PS have been compatibilized through graft copolymer formation between PA amine end-groups and anhydride-functionalized styrene copolymer to form a new imide linkage (Table 5.20). 

PEST/PPE blends have been compatibilized through graft copolymer formation between polyester and a PPE-miscible functionalized styrene copolymer (Table 5.39). In this instance, the reaction is between polyester carboxylic acid... 

PPE is not miscible with SMA containing as much as 28 % MA (Witteler et al. 1993). To compatibilize these two resins, Koning et al. (1993b, 1996) have added a monoamine-terminated PS that can form a graft copolymer with SMA. Since the amine-terminated PS is miscible with PPE, compatibilized PPE-SMA blends are obtained. Specifically, 30 parts of unfunctionalized PPE was blended (internal mixer at 220 °C, or mini-SSE at 280 °C, or TSE at 326 °C) with 56 parts SMA (28 % MA) and 14 parts amine-functionalized PS. The blend was characterized by TEM, SEM, mechanical and thermal properties, DMA, and GPC copolymer detection. The effect of pre-reacting amine-terminated PS with SMA was studied. The blend properties were compared to those for uncompatibilized blends. Blends were also made containing ABS -i- SEBS. Eurther examples of compatibilizing copolymer formation in PPE-styrene copolymer blends are shown in Table 5.43. 

PE -1- PP -f PS -1- PET -1- PA PE, PP, EPDM, PS, E/P copolymers functionalized (grafted) with maleic anhydride or acrylic acid, succinc anhydride, styrene, trimelitic anhydride... 

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