Synthesis and characterization of poly(ester ether siloxane)s

Abstract

A series of novel thermoplastic elastomers based on ABA-type triblock prepolymers, poly[(propylene oxide)-(dimethylsiloxane)-(propylene oxide)] (PPO-PDMS-PPO), as the soft segments, and poly(butylene terephthalate) (PBT), as the hard segments, was synthesized by catalyzed two-step melt transesterification of dimethyl terephthalate (DMT) with 1,4-butanediol (BD) and α,ω-dihydroxy-(PPO-PDMS-PPO) (M n = 2930 g mol −1 ). Several copolymers with a content of hard PBT segments between 40 and 60 mass% and a constant length of the soft PPO-PDMS-PPO segments were prepared. The siloxane-containing triblock prepolymer with hydrophilic terminal PPO blocks was used to improve the compatibility between the polar comonomers, i.e. DMT and BD, and the non-polar PDMS segments. The structure and composition of the copolymers were examined using 1 H NMR spectroscopy, while the effectiveness of the incorporation of α,ω-dihydroxy-(PPO-PDMS-PPO) prepolymer into the copolyester chains was controlled by chloroform extraction. The effect of the structure and composition of the copolymers on the transition temperatures (T m and T g ) and the thermal and thermo-oxidative degradation stability, as well as on the degree of crystallinity, and some rheological properties, were studied.

Analysis of dynamic mechanical, thermal and surface properties of poly(urethane-ester-siloxane) networks based on hyperbranched polyester

“…α,ω-Dihydroxy-(ethylene oxide-poly(dimethylsiloxane)-ethylene oxide) (EO-PDMS-EO; ABCR) was dried over molecular sieves (0.4 nm) before use. M n of the EO-PDMS-EO was calculated from the 1 H NMR (M n = 1200 g/mol) [21]. 4,4′-Methylenediphenyl diisocyanate (MDI; Aldrich, purity >98%) was used as received.…”

Synthesis and characterization of copolymers based on poly(butylene terephthalate) and ethylene oxide‐poly(dimethylsiloxane)‐ethylene oxide

“…Siloxane triblock prepolymer with poly(propylene oxide) (PPO) terminal blocks [a,x-dihydroxy-(PPO-PDMS-PPO)] was used in further investigations to increase the miscibility of the polar and nonpolar reactants during copolymer synthesis. 18,19 However, the presence of ether PPO chains in the siloxane-containing prepolymer did not improve the homogeneity of the prepared TPEES samples. All the TPEES samples were partially soluble in chloroform, as were the TPES samples based on PDMS-CP prepolymer.…”

“…1,2 Several studies on multiblock copolymers based on poly(butylene terephthalate), PBT, hard segments and soft segments based only on poly(organosiloxane)s or on combinations of poly(siloxane)s and polyethers have been presented since 1990. [7][8][9][10][11][12][13][14][15][16][17][18][19][20] The incorporation of poly(organosiloxane) segments into a polyester backbone results in improved clarity, surface smoothness, and nonsticking properties, as well as good film, fiber, and hydrophobic properties of the resulting copolymers, which is described in the patent literature. [21][22][23][24][25][26] Our research in the field of siloxane-containing copolymers is related to the synthesis of thermoplastic poly(ester-siloxane)s (TPES) and poly(ester-ethersiloxane)s, (TPEES), based on PBT as the hard segment, and different siloxane prepolymers as the soft segments.…”

Direct Synthesis of Poly(dimethylsiloxane) Copolymers with TPE‐Properties via CuAAC (Click Chemistry)

“…These are readily reversible making the TPE easier to process without curing steps and much more recyclable, thereby allowing for the recirculation of the valuable components into the silicon-cycle. TPEs that incorporate poly(siloxane)s are known from literature [1][2][3][4][5][6] and industry. [7] We have researched different possibilities for the synthesis of novel poly(siloxane) block copolymers considering both new (polar) hard blocks and formerly unused reactions to connect the siloxane and the organic building block.…”