Preparation of Block Copolymers with a Single T_g Based on Segments of Poly(oxy‐2,6‐dimethyl‐1,4‐phenylene) and Polycarbonate of Bisphenol A

Abstract

Summary: The synthesis and the properties of block copolymers based on PPO and PC segments are reported. Copolymers that have a multi‐block structure are synthesized by a polycondensation reaction that employs oligomeric PPO and PC diol terminated with phosgene or bischloroformate of bisphenol A. In the reaction scheme two steps are involved: first, the reaction of one of the oligomeric diols (PPO or PC) with the bischloroformate or phosgene; second, the oligomeric bischloroformate is reacted with the other diol. The molecular characteristics of the prepared samples are studied by SEC, 1H and 13C NMR, and FT‐IR spectroscopy. The thermal and rheological properties and the thermal stability have also been investigated by means of DSC, rotational rheometry, and TGA, respectively. Polymers that have a single glass transition temperature are obtained if low‐molecular‐weight segments are used. From a rheological point of view, these materials show a remarkably lower melt viscosity compared with a PPO homopolymer that has a comparable average molecular weight.

Full Characterization of a Multiblock Copolymer Based on Poly(2,6-dimethyl-1,4-phenylene oxide) and Poly(bisphenol-A carbonate)

“…PPO- b -PC is a relatively new block copolymer. In a previous article, we have reported the synthesis and the preliminary characterization of some PPO- b -PC multiblock copolymers showing one single T g and lower melt dynamic viscosity η compared to starting PPO homopolymer having similar average molar mass. These thermal and rheological properties are very important because are characteristic of high performance PPO- b -PC materials having potential good processability compared to the PPO homopolymer.…”

“…From a practical point of view a relatively simple method in obtaining polymeric materials based on PPO homopolymer showing good processability consists of blending it with traditional or modified polystyrene (PS). − Another classical method consists of synthesizing block copolymers based on PPO segments. In the past, General Electric Co. synthesized some di- and triblock PPO- b -PC copolymers based on high molar mass PPO showing two different T g . , On the contrary, an important finding of our previous study was that these new multiblock PPO- b -PC copolymers show one single T g if low molar mass starting PPO and PC blocks were used. − These new PPO- b -PC materials show remarkably lower dynamic viscosity of the melt compared with the PPO homopolymer having similar average molar mass. The PPO- b -PC copolymer could be also employed as a compatibilizer in PS/PC blends …”

“…A poly(bispenol A carbonate) sample terminated with bisphenol A groups (BPA) at both ends was prepared by a polycondensation reaction between the BPA and phosgene. The reaction was carried out in chloroform in the presence of two tertiary amines: N , N -diisopropylethylamine and 4-(dimethylamino)pyridine. ,, Finally, by using the PC-2OH sample and the four PPO-2OH samples, four different PPO- b -PC multiblock copolymers were prepared by coupling in the presence of phosgene or bisphenol A bischloroformate. First, an oligomeric PC bischloroformate terminated was obtained by the reaction of PC-2OH with bisphenol A bischloroformate in the presence of DIPEA.…”

“…First, an oligomeric PC bischloroformate terminated was obtained by the reaction of PC-2OH with bisphenol A bischloroformate in the presence of DIPEA. Later this product was reacted with PPO-2OH in the presence of DIPEA and DMAP (see Scheme and ref for details).

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“…In a previous study, we have reported synthesis and preliminary characterization of some new multiblock copolymers based on poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) and poly(bisphenol A carbonate) (PC) segments, referred in short as PPO- b -PC copolymers. Interest for PPO- b -PC macromolecular systems derives from their potential mechanical, rheological and thermal properties.…”