Use of statistical and multi-block copolymers as compatibilisers in PS/PC blends

作者：Penco M^*; Sartore L; Della Sciucca S; D'Amore A

来源：Journal of the Balkan Tribological Association, 2007, 13(4): 488-505.

• polystyrene
• polycarbonate
• poly(2,6-dimethyl-1,4-phenileneoxide)
• copolymer
• blend
• compatibility

In the first part of the work the compatibility of aromatic copolycarbonates containing bisphenol A (BPA) and tetramethyl bisphenol A (TMBPA) with polystyrene (PS) was investigated. Miscibility prediction data were used to select copolycarbonates of potential interest for developing high compatible blends. Statistical copolycarbonates (CPCs) containing different BPA/TMBPA molar ratios were synthesised by polycondensation reaction and the effect of copolymer composition on the PS/CPC miscibility was studied. The compatibility was evaluated by optical microscopy (OM), calorimetric (DSC) and dynamic-mechanical thermal (DMTA) analyses. Two glass transition temperatures were found for all the prepared PS/CPC blends, but an improvement of compatibility was obtained increasing TMBPA content in CPC copolymer. Blends of polycarbonate of bisphenol A (PCPA) and CPCs were characterised by a single glass transition temperature and transesterification reaction was noticed.
On the other hand, block-copolymers containing poly(2,6-dimethyl-1,4phenylene oxide) (PPO) and polycarbonate of bisphenol A (PC) segments were employed as compatibilisers in polystyrene (PS)/PC blends. Block-copolymers were prepared starting from oligomeric diols terminated PPO and PC. The poly(phenylene ethers) were obtained by oxidative coupling of 2,6-dimethyl-phenol in the presence of tetramethyl bisphenol A. The copolymers were obtained with a chain extension reaction between the starting oligomers using bischloroformate of bisphenol A or phosgene as coupling agent.
PS/PC blends, cast from chloroform solutions or mixed by melt, were studied by differential scanning calorimeter (DSC), dynamic-mechanical thermal analysis (DMTA) and optical microscopy (OP). The thermal and morphological analyses showed a clear compatibilsation effect between PS and PC if PPO-PC copolymer is added when blending is performed in the melt; in addition also mechanical properties are increased if compared with those of blends without PPO-PC.

• 出版日期2007