Data on the identification of isoprene and Styrene triblock copolymers with difunctional t-BuLi initiator

The data article refers to the paper “Synthesis of High-Vinyl Isoprene and Styrene Triblock Copolymers via Anionic Polymerization with Difunctional t-BuLi Initiator” [1]. Data presented here include the number average molecular weight (Mn), the weight average molecular weight (Mw), and polydispersity index (PDI) (Mw/Mn) of the triblock copolymers poly(styrene)-b-poly(isoprene)-b-poly(styrene) (PS-b-PI-b-PS, SIS) and poly(isoprene)-b-poly(styrene)-b-poly(isoprene) (PI-b-PS-b-PI, ISI). Mn of SIS and ISI were in the range of 208,000 to 274,000 (g/mol) and PDI of SIS and ISI are located at 1.18 to 1.2, respectively. The triblock copolymers were further identified with 2D HSQC NMR spectrum. Different vinyl content (1,2- and 3,4-addition units) of polyisoprene domains were characterized in the data.


Data description
The dataset contains raw data obtained the M n , M w , PDI (M w /M n ) for the SIS and ISI triblock copolymers. Besides, the characteristic of the SIS and ISI triblock copolymers were also identified by 2D HSQC NMR. Fig. 1 shows the gel permeation chromatography (GPC) traces of PI homopolymers and SIS Specifications Table   Subject Chemistry; Polymers and Plastics Specific subject area Anionic Living Polymerization  Type of data  Figures, Tables  How data were acquired Gel Permeation Chromatography (GPC), Refractive Index (RI) detector (Viscotek VE 3580), 2D NMR HSQC (Bruker AVANCE III HD 600 MHz spectrometer) Data format Raw, analysed data Parameters for data collection Elution solvent, column, detector, and environment temperature for GPC analyst.
Solvent, concentration for sample, and environment temperature for 2D HSQC NMR. Description of data collection GPC: Samples with different molecular weights and different vinyl groups were analysed by the RI detector after being injected into the instrument, and the computer collected data. 2D HSQC NMR: Samples with a fixed concentration were placed in the instrument, the data through Fourier transformed, and the file was output by the instrument software. Data source location Tainan, Taiwan Value of the Data Relevant data may be useful in the anionic polymerization of isoprene and styrene monomer, in particular for characteristic identification of isoprene with different structures. Further understanding of the behaviour of styrene polymerization with different vinyl content of polyisoprene from this data. These data could be meaningful for understanding the interaction between the reaction of styrene with different viscosity of vinyl content of polyisoprene. The identification methods for different vinyl content of polyisoprene are mostly 1 H NMR identification. In addition to 2D HSQC NMR, which can confirm the characteristic peaks efficiently, it can also analyse the corresponding isoprene structure of the H-backbone. Synthesis of SIS and ISI triblock copolymer with difunctional t-BuLi initiator may be the starting point for the further control the unique properties of block copolymers by using anionic polymerization.  Table 1. The SIS triblock copolymers were synthesized following the polymerization of PI. The higher apparent molecular weight of SIS was the evidence of the structural transformation from PI to SIS. The SIS triblock copolymers had M n values shown in Table 1 (see Fig.1).
On the other hand, the PS homopolymers had M n values which were shown in Table 2. The synthesized samples were named as PS(V)M, where V is the percentage of vinyl groups in the triblock copolymers and M is the number average molecular weight (M n ) of the PS homopolymers in kDa. The ISI triblock copolymers had M n values which were shown in Table 2 (see Fig. 2).   2D HSQC NMR spectroscopy experiments were performed to probe the relative positions of protons and their directly attached carbons in SIS triblock copolymers (Fig. 3). The main cross-signals in the aromatic regions of SIS(7)274 and SIS(90)246 were observed at dC ¼ 127.2e127.9 ppm and dH ¼ 6.9e7.2 ppm, respectively. The characteristic signals of 1,4-addition units in PI were observed at dC ¼ 123.0e126.0 ppm and dH ¼ 5.1 ppm. The chemical shift of dC ¼ 111.8 ppm represented the isomerization structure of 3,4-addition units in PI, which correlated with dH ¼ 4.6e4.75 ppm (Fig. 3(a)). Notably, the cross-signals in dC ¼ 110.1e113.8 ppm and dH ¼ 4.6e5.0 ppm represented the vinyl group isomerization structure (percentage of 1,2-and 3,4-addition units) in PI (Fig. 3(b)). Characteristic signals in the aliphatic region were observed at dC ¼ 15.9e47.8 ppm and dH ¼ 1.4e2.1 ppm.

Preparation of SIS and ISI triblock copolymer for GPC
The number average molecular weight (M n ), weight average molecular weight (M w ), and polydispersity index (PDI) (M w /M n ) of the triblock copolymers were determined by gel permeation chromatography (GPC) with a refractive index (RI) detector (Viscotek VE 3580). The system was equipped with three linear columns (SHODEX KF-803L, KF-804L, and KF-805L) at 30 C. Linear polystyrene (PS) was used for standard calibration, and THF (HPLC grade, Duksan) was the elution solvent at a flow rate of 1.0 mL/min. The injection concentration was 2.0 mg/mL and filtered before use.

Characteristic of SIS and ISI triblock copolymer with 2D HSQC
Nuclear magnetic resonance (NMR) spectroscopy measurements were performed using a Bruker AVANCE III HD 600 MHz spectrometer at 25 C for 2D HSQC, using deuterated chloroform (CDCl 3 ) as the solvent. 2D NMR HSQC determination was performed according to spectral widths of 3 kHz (5 ppm) for 1 H and 15 kHz (100 ppm) for 13 C. All NMR spectral analysis was conducted using Bruker Top Spin 4.0.4 software.