PC/ABS‐Mischungen haben als polymere Konstruktionswerkstoffe in den verschiedensten Anwendungsbereichen zunehmend an Bedeutung gewonnen, weil sie aufgrund ihres Legierungsaufbaues günstige Eigenschaftskombinationen besitzen. Obwohl diese Legierungen bereits seit längerem im Einsatz sind, liegen in der Literatur nur vergleichsweise wenige Untersuchungen über die grundlegenden physikalischen Aspekte vor. Mit den hier vorgestellten Untersuchungen wird der Einfluß unterschiedlicher Zusammensetzungen der Mischungen aus den Einzelkomponenten PC, SAN und Pfropfpolymerisat (SAN gepfropft auf Polybutadien) auf das Phasenverhalten sowie auf das Yield‐ und Bruchverhalten betrachtet und mit den Deformationsmechanismen in Verbindung gebracht. Eine nachfolgende Arbeit wird sich mit der Deformationsmorphologie befassen.

Oligomers with polymerizable endgroups are of increasing interest. These "macromers" 1, can be obtained by a transfer reaction with a telogen acting as transfer agent and initiator (inifer2)).This method can be applied to synthesize polytetrahydrofuran with acrylate and methacrylate endgroups (I)*), respectively. The polymerization is performed in bulk using protic initiators (super acids) and the corresponding carboxylic acid anhydride as a transfer agent. 8 0 II Acf-OCH,CH,CHzCHz+OAc Ac = H,C=$-C or H,C==CH-C 1 CH3 Experimental PartTHF was destilled from potassium/benzophenon under nitrogen immediately before use. To 150 ml of THF the anhydride (amount given in Tabs. 1 and 3) and 100 to 200 mg of 2,6-dimethylphenol (ionol, as inhibitor of radical polymerization) were added. The mixture was cooled to about -10°C and the initiator was added (e.g. 0,i ml of HSbF6 or 0,4 g of acetyl-hexachloroantimonate~, The mixture was heated to the reaction temperature of 40 "C.The course of the reaction was followed by IR-spectroscopy. When the complete consumption of the anhydride was indicated 0,5 ml of water were added. The mixture was diluted by adding 100 ml of THF, and the SbF6-ions were removed by an anion exchanger (Serva IRA 400). The solution was treated i.vac. to remove solvent and water. The product is a colourless to pale yellow viscous liquid or wax like material depending on the molecular weight.M,, values were obtained by vapour pressure osmometry using a Knauer instrument. The ester functionality was determined by titration of the hydrolyzed sample. 0,4 to 1 g of the product were dissolved in 100 ml of dry THF. 3 -5 ml of 1 N KOH were added and the mixture was heated to reflux for 3 h. After adding 100 mi of water the acid was titrated by use of a Mettler Memo-Titrator DL 40.The initiators HSbF6 (from Aldrich), CF,SO,H (from Fluka), and acetylhexachloroantimonate (from Ega) were used as received. Acrylic anhydride (from Atlanta) contained 16% *) Systematic name: a-methacryloyl-(or acryloyl)-o-methacryloyIoxy-(or acryIoy1oxy)poly-(oxytetramethylene).

Tetrahydrofuran (THF) was polymerized by protic and non-protic cationic initiators in presence of acetic anhydride (A5O) in methylene dichloride. Due to a low transfer coefficient (CAczO = 0,058) the molecular weight increases during the early part of the reaction. The consumption of A 5 0 continues even when the THF concentration approaches zero, which results in a lowering of the number-average degree of polymerization P,. Degradation of poly(THF) continues until the A 5 0 is exhausted. The equilibrium concentration of THF can reach almost zero at small P, . The equilibrium constants K2, K 3 , K4, etc., up to KZ3 for the successive monomer additions are obtained from gel permeation chromatography. With the exception of K, the equilibrium constants K, are independent of n.Tetrahydrofuran (THF) was refluxed and freshly distilled from potassium/benzophenone. Acetic acid was distilled from acetic anhydride using an effective rectifying column. The anhydride was refluxed and distilled using 4,4'-methylenedi(phenyl isocyanate) as drying agent and dibutyltin dilaurate ((C4Hg),Sn (O2CCl H,, )2) as a catalyst in a circulating distillation. The purity was better than 99,8% as checked by gas chromatography.Dichloromethane was dried with methylphenylene diisocyanate (techn. grade, mixture of isomers) and dibutyltin dilaurate. After distillation it was stored over CaH,; HSbF, (Aldrich) was used as received. PolymerizationAppropriate amounts of THF, acetic anhydride and methylene dichloride as given in Tabs. 3, 4, 5 and 7 were directly distilled into the reaction vessel from three circulating distillations. The mixture was cooled to between -10 and -20 "C and the catalyst was added. The reaction vessel was heated to the temperature desired. The consumption of acetic anhydride was followed by measuring samples by IR-spectroscopy ( Fig. 1). At the end of the reaction 0,s ml of water was added, and the SbF,-ions were removed by an anion exchanger. The reaction products were isolated by removing the monomer, solvent, and water by evaporation und vacuum.The ester functionality was determined by titration of a hydrolyzed sample; 0,4 to 1 g of the product was dissolved in 100 ml of dry THF; 3 -5 ml of 1 M KOH was added and the mixture was heated to reflux for 3 h. After adding 100 ml of water the acid was titrated using a Mettler Memo-Titrator DL 40. The reproducibility of the determination of the ester functionality is 2,5%. The error is mainly caused by the uncertainty of the number-average molecular weight M n .

Condensation polymers with block structure are stable only if one of the constituent blocks is stable against reactions like transesterification, transamidation, etc. This stable block must have a pure CC chain which may be interrupted by ether, sulfide or sulfone linkages. It must be strictly bifunctional in order to be no limiting factor for the molecular weight in the synthesis of blockcopolymers. If the two functional groups are located at both ends of the polymer chain, we name this product a telechelic. The characterization of telechelics needs the determination of the functionality. Any end group analysis will give only average values. An efficient chromatographic method is necessary to guarantee that bifunctionality is caused by one polymer homologous series. A number of commercial telechelic polytetrahydrofuranes are strictly bifunctional as shown by GPC1). Two functional end groups can be introduced either by bifunctional initiation and killing the living end groups by a proper nucleophile. The disadvantage of this method is that one mole of an expensive initiator is needed to produce one mole of polymer. The second method to introduce functional end groups uses a proper transfer agent. Only catalytic amounts of initiator are necessary in this case.