A convenient one-pot method for the controlled synthesis of polystyrene- block -polycaprolactone (PS- b -PCL) copolymers by simultaneous reversible addition?fragmentation chain transfer (RAFT) and ring-opening polymerization (ROP) processes is reported. The strategy involves the  use of 2-(benzylsulfanylthiocarbonylsulfanyl)ethanol (1) for the dual roles of chain transfer agent (CTA) in the RAFT polymerization of styrene and co-initiator in the ROP of ε -caprolactone.  One-pot poly merizations using the electrochemically stable ROP catalyst diphenyl phosphate (DPP) yield well-defi ned PS- b -PCL in a relatively short reaction time (≈4 h; Mn = 9600−43 600 g mol−1 ; Mw/Mn = 1.21−1.57). Because the hydroxyl group is strategically located on the Z substituent of the CTA, segments of these diblock copolymers are connected through  a trithiocarbonate group, thus offering an easy way for subsequent growth of a third segment between PS and PCL. In contrast, an oxidatively  unstable Sn(Oct) 2 ROP catalyst reacts with (1) leading to multimodal distributions of polymer chains with variable composition.Fil: de Freitas, Augusto G. O.. Universidade Federal de Santa Maria; BrasilFil: Trindade, Suelen G.. Universidade Federal de Santa Maria; BrasilFil: Muraro, Paulo I. R.. Universidade Federal de Santa Maria; BrasilFil: Schmidt, Vanessa. Universidade Federal de Santa Maria; BrasilFil: Satti, Angel Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); ArgentinaFil: Villar, Marcelo Armando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); ArgentinaFil: Ciolino, Andrés Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Bahía Blanca. Planta Piloto de Ingeniería Química (i); ArgentinaFil: Giacomelli, Cristiano. Universidade Federal de Santa Maria; Brasi

Ciolino, Andrés Eduardo

de Freitas, Augusto G. O.

Giacomelli, Cristiano

Muraro, Paulo I. R.

Satti, Angel Jose

Schmidt, Vanessa

Trindade, Suelen G.

Villar, Marcelo Armando

Macromolecular Chemistry and Physics

CONICET Digital

Copyright WILEY-VCH Verlag GmbH & Co. KGaA, 69469 Weinheim, Germany, 2013.         Supporting Information   for Macromol. Chem. Phys., DOI: 10.1002/macp. 201300416  Controlled One-Pot Synthesis of Polystyrene-block-Polycaprolactone Copolymers by Simultaneous RAFT and ROP  Augusto G. O. de Freitas, Suelen G. Trindade, Paulo I. R. Muraro, Vanessa Schmidt, Angel J. Satti, Marcelo A. Villar, Andrés E. Ciolino, Cristiano Giacomelli*       - 1 -   Copyright WILEY-VCH Verlag GmbH & Co. KGaA, 69469 Weinheim, Germany, 2011.  Supporting Information   for Macromol. Chem. Phys, DOI: 10.1002/macp.201300416   Controlled One-pot Synthesis of Polystyrene-b-Polycaprolactone Copolymers by Simultaneous RAFT and ROP  Augusto G. O. de Freitas, Suelen G. Trindade, Paulo I. R. Muraro, Vanessa Schmidt, Angel J. Satti, Marcelo A. Villar, Andrés E. Ciolino, Cristiano Giacomelli*         - 2 -  S1. Results   Figure S1. Assigned 1H NMR spectra in CDCl3 for PCL, PS and PS-b-PCL polymers synthesized using (1) in the dual roles of CTA for RAFT of styrene and coinitiator for ROP of ε-CL mediated by DPP. Selected shifts associated with (1) are indicated by a symbol (*).          - 3 -  GPC analysis with selective detection of trithiocarbonate function by UV at 433 nm (chain extension experiment) 104 105UV (433 nm) UV (433 nm)Molar Mass (g/mol)PCL macroCTAPS-b-PCL (chain extension) Figure S2.  GPC chromatograms recorded with UV-vis detector set at the λmax of (1) (433 nm) for a PCL macroCTA prepared using DPP as the catalyst for the ROP process (Table 1, entry 1), and corresponding chain extension by RAFT polymerization of styrene (Table 1, entry 2).        - 4 -  Analysis of chain-end functionalization with triothiocarbonate groups by UV-vis  00.020.040.060.080.10.120.140.16360 400 440 480 520 560 6000369Abs. (a.u.)Wavelength (nm)Volume of 1.0 M CTA added (μL)(A)00.020.040.060.080.10.120.140.16-2 0 2 4 6 8 10Abs = 0.0236 + 0.014533*Volume   R= 0.99994Abs @ λ max = 433 nm (a.u.)Added volume of 1.0 M CTA stock solution (μL)(B) Figure S3. (a) UV-vis spectra recorded in THF showing the typical absorption band of (1) centered at 433 nm for a 15.0 mg/3.0 mL PCL macroCTA sample (entry 1, Table1, main document) and subsequent addition of indicated volumes of 1.0 M CTA stock solution; (b) corresponding standard addition plot used to determine the amount of CTA present in the polymer sample. The amount of CTA found corresponds to 105% chain-end functionalization for the PCL macroCTA sample (entry 1, Table 1, main document).     Conversion and Mn(theo) calculation  Theoretical molar masses (Mn(theo)) and degree of polymerization (DP(theo)), were calculated from the conversion of styrene determined by 1H NMR analysis of a reaction aliquot containing anisole as the internal reference, assuming quantitative efficiency of (1) (Figure S2, spectrum a and b), and from 1H NMR integral ratio corresponding to PS  A(7.3- 6.3)  and PCL  A(4.2 - 3.9) protons (Figure S2, spectrum c). The NMR integral area between 3.77 and 3.68 ppm  A(3.77 - 3.68) , assigned to -OCH3 anisole protons, is initially set to 3.0 at t = 0, where t is the reaction time (Figure S2, spectrum a).       - 5 -   Figure S4. 1H NMR spectra in CDCl3 for a one-pot reaction mixture before (A) and after (B) the polymerization, and for the pure (precipitated) PS-b-PCL copolymer product (C).        - 6 -  Hydrolysis of PS-b-PCL block copolymer yielding PS homopolymer as product  Figure S5. GPC traces of a PS-b-PCL copolymer synthesized in a one-pot polymerization procedure and corresponding hydrolyzed product obtained after 24 h of reaction at 85 °C in 30% wt. HCl.  Figure S6. 1H NMR spectra of a PS-b-PCL copolymer synthesized in a one-pot polymerization procedure and corresponding hydrolyzed product obtained after 24 h of reaction at 85 °C in 30% wt. HCl.        - 7 -  Chain extension experiment using a Sn(Oct)2-made PCL macroCTA for the RAFT polymerization of styrene  Figure S7. GPC chromatograms of a PCL macroCTA prepared using Sn(oct)2 as catalyst for ROP process (Table 1, entry 10), and corresponding chain extension by RAFT polymerization of styrene (Table 1, entry 11).                     - 8 -   GPC analysis with selective detection of trithiocarbonate function by UV at 433 nm (one-pot reaction with Sn(Oct)2 catalyst)  Figure S8. GPC chromatograms recorded with three detection settings (as indicated) in THF for 5.0 mg/mL of polymer sample resulting from a one-pot polymerization experiment involving simultaneous RAFT and ROP processes in the presence of Sn(Oct)2 catalyst (Table 1, entry 12, main document).       - 9 -   Chain extension experiment using PS-b-PCL macroCTA made in a one-pot simultaneous RAFT and ROP in presence of Sn(Oct)2   Figure S9. GPC chromatograms of a PS-b-PCL copolymer prepared using Sn(oct)2 as the catalyst for ROP process (experimental conditions: [CTA]:[I]:[Sn(Oct)2]:[St]:[CL] = 1:0.25:0.5:150:150, [St]0 = [CL]0 = 2.88 M, T = 120 ˚C) and used for further chain extension by RAFT polymerization of styrene (experimental conditions: [PS-b-PCL macroCTA]:[I]:[Sn(Oct)2]:[St]:[CL] = 1:0.25:−:200:−, [St]0 = 2.88 M, T = 120 °C).           - 10 -   Figure S10. GPC chromatograms in THF at 5.0 mg/mL of the polymer obtained in a one-pot/two-step polymerization experiment involving RAFT first (step 1, 7 h), and then simultaneous RAFT (thermally initiated) and ROP processes in the presence of Sn(Oct)2 catalyst (step 2, + 5 h, conv.(St) = 73%, conv.(CL) = 77%). Experimental conditions: [CTA]:[I]:[Sn(Oct)2]:[St]:[CL] = 1:0.25:0.5:200:200, [St]0 = [CL]0 = 2.88 M, T = 120 ˚C.   

Controlled One-Pot Synthesis of Polystyrene-block-Polycaprolactone Copolymers by Simultaneous RAFT and ROP

LAReferencia - Red Federada de Repositorios Institucionales de Publicaciones Científicas Latinoamericanas

English

http://onlinelibrary.wiley.com/store/10.1002/macp.201300416/asset/supinfo/macp201300416-sup-0001-S1.pdf?v=1&s=8d707c1e8ade7ad2e7a87f56330c759f57a65bef

Controlled One-Pot Synthesis of Polystyrene-block-Polycaprolactone Copolymers by Simultaneous RAFT and ROP

Abstract

Similar works

Full text

Available Versions

CONICET Digital

LAReferencia - Red Federada de Repositorios Institucionales de Publicaciones Científicas Latinoamericanas