“…The following reagents were used: 1,4-butanediol (BD-1,4, Sigma-Aldrich, USA), dimethyl terephthalate (DMT, Chemical Plant ''Elana,'' Poland), poly(oxytetramethylene)diol with molecular weight 1000 g mol -1 (PTMO, Du Pont, USA), a,x-dicarboxylicoligo(laurolactam) with molecular weight 2250 g mol -1 prepared in our laboratory [26][27][28][29][30], a titanate catalyst (TiO 2 /SiO 2 , Sachtleben Chemic GmgH, Germany), thermal stabilizer (Irganox 1010, Ciba Geigy, Swiss).…”