Nunzia Galdi, Antonio Buonerba,* Patrizia Oliva and Leone Oliva*
A judicious choice of a polyinsertion catalyst and monomer feed composition allows the one-pot synthesis
of ethylene–styrene copolymers with an unprecedented structure, containing an isotactic polystyrene (iPS)
block joined to an isotactic ethylene-alt-styrene sequence (iP(E-alt-S)). Both segments in the native
polymer give rise to crystallinity. The characterization of the materials has been performed through
different techniques. In particular AFM analysis of samples obtained by spin coating shows the presence
of either circular nano-domains with about a 30 nm diameter due to self-assembling of the copolymer
chains or bicontinuous nanostructured phases depending on the block lengths.
Introduction
Since the rst reports on the ethylene–styrene (E–S) copoly-merization1,2 a variety of materials having structures with widelydifferent properties has been described.3
At rst, the paper of one of us1 as well as the Dow patent2
reported the copolymerization of the two monomers in thepresence of homogeneous polyinsertion catalysts to give anamorphous or semi-crystalline material depending on theamount of styrene incorporated into the polymer chains. Suchcrystallinity, when present, is due to the packing of the poly-ethylene sequences, as inferred from the X-ray diffractionpattern. In contrast when the molar styrene content is over 20%the material is amorphous and shows an elastomericbehaviour.4
Furthermore ethylene and styrene can copolymerize togive alternating copolymers with either an atactic5 orisotactic6–8 stereostructure. The isotactic one shows a meltingpoint close to that of polyethylene but with an X-raydiffraction pattern denoting a typical crystallinity due to thepacking of the regular sequences in a trans planar confor-mation.9 This result is obtained by using stereoselectivepolyinsertion catalysts based on zirconocene complexes andcan be justied with the peculiar behaviour of the styrenemonomer when it inserts in the secondary manner into themetal–carbon bond.10
Indeed when the styrene inserts with primary regiochemistrya widely different structure of the copolymers is obtained. Thisis what happens in the presence of a hindered zirconocene that
produces an E–S copolymer with a block-wise structure ofisotactic polystyrene sequences and polyethylene sequences.11
The literature also reports living polymerizations by meansof catalysts through a ne tuning of the Ziegler–Natta catalyst,co-catalysts, as well as the polymerization conditions in terms ofmonomer pressure and temperature.12 The key-point for theachievement of living polymerization conditions lies in theprevention of termination reactions as the b-elimination andpolymer chain transfer to the co-catalyst.
Recently, our studies on the styrene polyinsertion catalysisshowed, at low temperature, the substantial absence of spon-taneous chain transfer processes,13 thus suggesting the possi-bility of obtaining new E–S architectures through suitable co-monomer feed.
In the present paper we report on the facile synthesis ofethylene–styrene copolymers able to control their spatial orga-nization in the solid phase and thus enrich the armoury of somaterials attractive as scaffolds for engineering ofnanostructures.14
Experimental sectionGeneral considerations
All the moisture sensitive operations were carried out in anatmosphere of nitrogen using standard Schlenk techniques. Drysolvents were freshly distilled before use. Toluene was keptunder reux in the presence of sodium for 48 h and thendistilled in an atmosphere of nitrogen. Styrene (99%, Aldrich)was puried by stirring for 1 h over calcium hydride beforedistillation under nitrogen at reduced pressure. Methyl-aluminoxane (MAO) supplied by Aldrich as a 10 wt% solution intoluene was dried to form a white powder by removing in vacuothe solvent and traces of trimethylaluminum. rac-Methylene-bis(1-indenyl)zirconium dichloride was prepared by using theprocedures described in the literature.15 Other materials andreagents available from commercial suppliers were generallyused without further purication.
Polym. Chem., 2014, 5, 3045–3052 | 3045
Polymer Chemistry Paper
Measurements and characterization1H and 13C NMR spectra in solution were recorded on a BrukerAvance 300-MHz spectrometer (75.48 MHz for 13C). The sampleswere prepared by dissolving 25 mg of the polymer into 0.5 mL of1,1,2,2-tetrachloro-ethane-d2 (C2D2Cl4). The spectra wererecorded at 373 K with D1 ¼ 2 s, and the chemical shis refer tothe central peak of C2D2Cl4, which was used as an internalreference at d¼ 74.26 ppm. The average length of the sequenceswas evaluated from the area of methylene resonances from eqn(1) and (2) (see Fig. 1 for the adopted notation):
Mn ¼ n104 + m132 (1)
n/m ¼ A(Saa)/A(Sbb) (2)
The styrene unit content in the copolymers was evaluatedfrom the area of the methylene signals in the 13C NMR spectrathrough the following equation (eqn (3)):
where A(Sag) represents the area of the peak of the methylenecarbon at 36.8 ppm and so on (see Fig. 1). The peaks not labelledin Fig. 1 have been assigned to defects with respect to the strictlyregioregular alternating copolymer: at 27.5 ppm the Sbd, at29.9 ppm the Sgg and at 35.0 ppm the Sab.
Solid-state 13C NMR experimentswereperformedon thesameBruker Avance 300MHz spectrometer operating at 75.48MHz for13C. The samples were packed in the zirconium rotors of 4 mmand were spun at a rate of 9 kHz, which is fast enough to removespinning sidebands for aliphatic and aromatic carbons at thiseld strength. The spectra were acquired using magic-anglespinning with cross polarization pulse sequence (CP-MAS) with a
Fig. 1 13C NMR spectra in solution of the aliphatic region of thealternate E–S copolymer, sample 1 (a) and of the diblock copolymer ofsample 2 (b) of Table 1.
3046 | Polym. Chem., 2014, 5, 3045–3052
contact time of 5ms, at room temperature by using a pulse lengthof 2.9 ms (90�) with an acquisition time of 0.022 s and a recycletime of 5 s to ensure quantitative detection. For each spectrum30K transients were accumulated. All 13C peaks were referenced tothe upeld peak of adamantane centred at d ¼ 29.5 ppm.
Gel permeation chromatography (GPC) analysis was per-formed at 135 �C using a Waters Instrument GPCV 2000equipped with viscometer and refractive index detectors, usinga four column set purchased from PSS-USA with a particle sizeof 10 mm and pore sizes of 106, 105, 104 and 103 A. 1,2-Dichlorobenzene was the carrier solvent used with a ow rate of1.0 mL min�1. The calibration curve was established withcommercial polystyrene standards.
The analysis by temperature raising elution fractionation(TREF) was carried out with a fully automated preparative TREFinstrument PREP mc2 from Polymer Char. o-Xylene, mixed withpentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionate) as a stabilizer (0.5 g L�1), was used either for dis-solving the sample (306 mg) and as an eluent. The sample wasdissolved at 135 �C, cooled at 5 �C min�1 to 115 �C and kept atthis temperature for 30 min and then cooled to 30 �C at 0.1 �Cmin�1 in order to afford slow polymer crystallization. Aer30 min the collection of the fractions was started at thefollowing temperatures: 30, 50, 70, 90, 110 and 130 �C. Weadopted a heating rate of 20 �Cmin�1 and an equilibration timeof 20 min. The copolymer samples were isolated by precipita-tion in acetone, followed by drying to constant weight.
Wide-angle X-ray diffraction (WAXD) patterns with nickelltered Cu Ka radiation were obtained, in reection, using anautomatic Bruker D8 diffractometer.
Differential scanning calorimetry (DSC) measurements,recorded from the rst heating run, were carried out with a DSC2920 TA Instruments in a owing nitrogen atmosphere with aheating rate of 10 �C min�1.
Tapping mode atomic force microscopy (TM-AFM) images ofthin lms were collected in air at room temperature with aDimension 3100 coupled with a Bruker Nanoscope V controller.The specimens to be analyzed were obtained by spin-coatingchloroform solutions (30 mL; 0.2 wt%) onto glass slides using aspeed rate of 1500 rpm for 30 s and a starting acceleration of2000 rpm s�1 at room temperature. Commercial probe tips withnominal spring constants of 20–100 N m�1, resonancefrequencies in the range of 200–400 kHz and tip radii of 5–10nm were used. The images were analyzed using the Brukersoware Nanoscope Analysis v1.40r2sr1.
Ethylene–styrene copolymerization
The copolymerizations were carried out in a 100 mL glass askprovided with a magnetic stirrer and thermostatted at 0 �C. Thereactor was sequentially charged under an ethylene atmosphere(sample 1, Table 1) or a nitrogen atmosphere (samples 2, 5 and6, Table 1) with styrene (10 mL), MAO (0.3 g), and rac-methyl-ene-bis(1-indenyl)zirconium dichloride (5 mg) (Al/Zr molar ratio¼ 500). For the samples 2, 5 and 6 the inert atmosphere wasremoved aer the lapse of time reported in Table 1 and thereaction mixture was saturated with ethylene and the gaseous
monomer at atmospheric pressure was continuously fed to keepits concentration constant in the reaction medium; nallypouring the mixture into 100 mL of acidied ethanol stoppedthe copolymerizations. Then the polymers were recovered byltration, washed three times with fresh ethanol and driedin vacuo at 70 �C. The raw polymers of samples 2, 5 and 6 werefurther washed with boiling butanone in a Kumagawa-typeextractor in order to remove some ethylene-alt-styrene copoly-mer not linked to polystyrene sequences (weight fraction lessthan 10%). The copolymer yields span between 300 and 500 mg.
The syntheses of the samples 3 and 4 were carried out in aglass tube inside a stainless steel reactor following the sameprocedure as that used for the syntheses of samples 2, 5 and 6except for the different liquid phase (15 mL of styrene dilutedwith the same volume of toluene) and the ethylene pressureadjusted respectively to 5 and 15 atm. At the end of thecopolymerization the gaseous monomer was vented off, themixture poured into acidied methanol and the polymer wastreated as usual.
Styrene polymerization
The styrene polymerization (sample 7, Table 1) was carried outin a 100 mL glass ask provided with a magnetic stirrer andthermostatted at 0 �C. The reactor was sequentially chargedunder a nitrogen atmosphere with styrene (10 mL), MAO (0.3 g),and rac-methylene-bis(1-indenyl)zirconium dichloride (5 mg)(Al/Zr in mol ¼ 500). Aer 60 min the reaction mixture waspoured into acidied methanol and the polymer was treated asusual. The yield was 0.3 g.
Results and discussion
A series of copolymerizations have been carried out by using thecatalyst based on the C2 symmetric zirconocene rac-methylene-bis(1-indenyl)zirconium dichloride activated by methyl-aluminoxane (MAO).
By feeding styrene and ethylene at atmospheric pressure tothis system, a strictly alternate copolymer is obtained with astereoregular isotactic structure (Scheme 1; sample 1 ofTable 1). This copolymerization was performed in a glass askloaded with MAO dissolved in styrene, by injecting a solution ofthe metallic complex into a small amount of toluene under anethylene atmosphere. The mixture was kept for one hour toreact under continuous ethylene feed. The copolymer 13C NMRspectrum exhibits the resonances of the alternate sequence at25.5, 36.8, and 45.7 ppm as the main peaks of the aliphaticregion (0–50 ppm relative to TMS) (Fig. 1a). The other copoly-merizations were carried out by following, in the starting phase,the same procedure except for the atmosphere that wasconstituted of nitrogen. Aer a varying lapse of time, the inertgas was vented off and substituted by the ethylene atmosphere,with continuous feed.
A typical 13C NMR spectrum of such a copolymer (sample 2 ofTable 1) is reported in Fig. 1b. In the aliphatic region one canrecognize at 41.3 (Saa) and 43.5 (Tbb) ppm the peaks assigned tothe isotactic polystyrene sequences and the three signals at
Polym. Chem., 2014, 5, 3045–3052 | 3047
Scheme 1 Polymerization of ethylene and styrene by rac-CH2(1-indenyl)ZrCl2/MAO.
Fig. 2 WAXD pattern labelled with reflection assignments of iPS17 (#)and iP(E-alt-S)9 (*) crystallinity of sample 2 in Table 1.
Polymer Chemistry Paper
25.5 (Sbb), 36.8 (Sag + Sga) and 45.7 (Tdd) ppm with a 1 : 2 : 1intensity ratio due to the alternating ethylene–styrene sequencewith isotactic conguration.
The molecular weight distribution and the mono modalshape of the GPC curves indicate a homogeneous structuralcomposition of the macromolecules, i.e. a block-wise structurewith the isotactic polystyrene sequence joined to the alternatingethylene–styrene sequence (see Fig. S1‡). The broadening ofMw/Mn ratios (Table 1) with respect to the expected values for aliving copolymerization could be justied as a result of a slowinitiation process at the adopted reaction temperature.
As an additional method for the investigation of the polymerstructure, TREF analysis was performed on sample 6, followingthe method described in the experimental part. This samplewas chosen due to its high iPS content in order to enhance theeventual separation of the low melting alternate E–S segmentsfrom the crystalline iPS not linked. The sample was quantita-tively recovered in a single TREF fraction that, characterized by13C NMR spectroscopy, revealed a chemical compositionperfectly matching with that of the starting polymer sample (seeFig. S2 and S3‡). The polymer in the TREF elution behaved as ahomogeneous material, i.e. a diblock copolymer with iPSsegments joined to the iP(E-alt-S) sequences.
The stereoregular sequences are long enough to organizethemselves into distinct crystalline domains. Actually the X-raypowder diffraction patterns of sample 2 show the presence ofdiffractions due to both the isotactic polystyrene17 and theisotactic ethylene-alt-styrene sequences9 (Fig. 2).
The same evidence can be drawn from the DSC analysis ofthe as-polymerized material. Melting endothermic peaks aregenerally observed around 130� and 225 �C, assigned respec-tively to melting of the iP(E-alt-S) and the iPS crystalline phases(Fig. 3). The melting peaks and the corresponding enthalpyvalues in Fig. 3 can be related to the copolymer composition. Sothe lower melting-point of the iP(E-alt-S) crystalline phase forsamples 2–6 in Table 1 with respect to the corresponding valueof 134 �C for the mono-block copolymer (sample 1) could beseen as further evidence of the block-wise structure of the title
3048 | Polym. Chem., 2014, 5, 3045–3052
copolymers. On the other hand the crystallinity degree of the iPSsegments, evaluated from the literature value of 64.3 J g�1
tabulated by Mandelkern et al.,16 seems affected by the presenceof the iP(E-alt-S) segment (Table 1) in a way that is not easy torationalize.
For sample 2, with a high content in the alternate E–Ssegment, a more complex thermal behaviour is observed, withmultiple melting peaks. Actually a bimodal peak, with maximaat 82 and 92 �C, was detected immediately before the expectedmelting of the iP(E-alt-S) occurring at 125 �C (Fig. 3a). A similarthermal behaviour was previously observed for the alternate E–Scopolymers by Arai et al., but no attempt to explanation wasreported.7b At present the origin of multiple melting peaks ofpolymers is still a matter of debate and, oen, a single reason isnot discernible due to the overlap of the contribution of a varietyof sources as: (1) the crystalline polymorphism; (2) the relaxationof the rigid or constrained amorphous phase; (3) the sizedistribution of the crystalline regions and of the lamellar
Fig. 3 DSC traces of iPS-b-iP(E-alt-S) diblock copolymers of Table 1:(a) sample 2, (b) sample 3, (c) sample 5 and (d) sample 6.
Fig. 4 Comparison of CP-MAS 13C NMR spectra in the aliphatic regionof the copolymers: (a) the alternate sample 1; (b) the diblock sample 2;and (c) the diblock sample 5.
Paper Polymer Chemistry
thickness; (4) the multimodal distribution of the molecularweights; (5) imperfection of the crystalline regions prone toreorganization, perfection, or even recrystallization.16a,18 Theexistence of an extra crystalline phase, different from the crys-talline iPS and iP(E-alt-S) phases, is ruled out by the WAXDpattern reported in Fig. 2. The analysis by DSC of sample 2 aerannealing at 100 �C for 5min evidenced the disappearance of theextra-peak and the contemporary increase of the area of the peakaround 130 �C (see Fig. S4 in the ESI‡). Imperfect crystalline oreven constrained amorphous regions of the alternate E–Ssegments able to afford a perfectly crystalline phase could be asource for the existence of this low temperature melting peak.
Sample 2 shows relevant length of both sequences. Its Mn isabout 77 kDa and from this value and from the integration ofthe methylene signals in the 13C NMR spectrum one can eval-uate the average length of the sequences by using the ratio ofthe peak areas of the Sbb and of the Saa. It results for the poly-styrene an average sequence of 216 units, and for the ethylene-alt-styrene sequences an average of 413 E–S units. The otherfeeding conditions in contrast give rise to copolymers withlargely prevailing polystyrene sequences.
Some insight into the chain arrangement in the crystallinephase can be obtained from the analysis of the CP-MAS 13CNMRspectra. In Fig. 4 we report the comparison of the aliphaticregion of three copolymers. The isotactic alternate copolymer(Fig. 4a) shows three main peaks, with about 1 : 2 : 1 intensityratio, that can be assigned to the secondary carbons, Sbb (31ppm) and Saa (40 ppm), and to the tertiary one Tdd (51 ppm).These resonances are downeld from the corresponding values
observed in solution (25.5, 36.8, 45.7 ppm respectively), soindicating less gauche character, in accordance with the zig-zagchain conformation previously proposed on the basis of X-raydiffraction studies.9
The block-wise copolymers exhibit the same pattern with, inaddition, a broad signal due to the coalescence of the twoaliphatic carbons of the isotactic polystyrene arranged in theusual helix conformation.11 The copolymer sample 2 is reportedin Fig. 4b, with prevalence of the alternating sequence while, incontrast, the copolymer sample 5 (Fig. 4c) shows weak signals ofthe alternate sequence beside the strong signal of the prevailingisotactic polystyrene sequence. As a consequence from these CP-MAS NMR spectra one can argue that in the solid-state poly-styrene sequences in helix conformation coexist with alternateethylene–styrene sequences in planar zig-zag conformation.
Additional evidence of the phase separated architecture ofthe iPS-b-iP(E-alt-S) diblock copolymers comes from the analysisof their thin lms by atomic force microscopy operating intapping mode (TM-AFM), prepared by spin coating of polymersolutions in chloroform (0.2 wt%). In TM-AFM a sharp tip(probe), excited by an external signal at a frequency close to itsresonance value with a given amplitude set point value, scansthe surface providing simultaneously information about thetopography and the phase distribution in the specimen.19 In(chemically) phase separated materials, the TM-AFM maps thephase distribution as a (physical) phase shi betweenthe excitation and the response of the tip, as a consequence ofthe different mechanical properties, including stiffness, elas-ticity and adhesion. As a reference, a fully alternating E–Scopolymer (sample 1 of Table 1) has been analyzed by TM-AFM,exhibiting a at surface without any specic structural organi-zation of the surface as conrmed by the corresponding phasecontrast image (Fig. 5a and S5‡). The introduction of a segmentof iPS in the polymer backbone, for sample 2 (23 wt% of iPS),
Polym. Chem., 2014, 5, 3045–3052 | 3049
Fig. 5 Height (on the left) and phase contrast (on the right) TM-AFM micrographs of the samples: (a) 1; (b) 2; (c) 3; (d) 4; (e) 6; and (f) 7.
Polymer Chemistry Paper
does not produce signicant changes of the surface topographyas shown in the height image in Fig. 5b and S6.‡ In contrast, thecorresponding phase image shows the presence of a circularrigid domain (represented as bright reliefs), with an averagediameter of 27 nm, embedded in a so polymer matrix (repre-sented as a dark ground; see Fig. 5b and S6‡).14 On the basis ofthe polymer composition and the different mechanical prop-erties of the polymer segments, one can argue that the rigidphase consists of iPS, whereas the soer matrix is constituted bythe alternating E–S segments. Unfortunately from the scanningof the surface by means of TM-AFM it is not possible todiscriminate whether these circular domains are crystalline aswell as whether they are due to isolated spheres or the verticallyaligned cylindrical array of iPS domains. An increase of the iPScontent (sample 3, 51 wt%) produces considerable changes ofthe surface morphology (Fig. 5c and S7‡). A typical polymericbicontinuous nanostructure is clearly visible in the relativephase contrast image,14 with a thickness of the domains foundin the range of 40–70 nm. For sample 4, a similar morphologywas observed with a slightly higher iPS content of 59 wt%, wherethe phase thickness ranges between 50 and 80 nm (Fig. 5d, S8and S9‡). Also in these cases, by TM-AFM it is not possible toidentify the morphology of the bulk material, i.e. if thesebicontinuous phases are constituted of defective lamellae orsubstrate aligned cylinders. As a comparison a thin lm of asolution blend of the iPS homopolymer (sample 7) and thealternate iP(E-alt-S) copolymer (sample 1) with a composition of50 wt% of iPS adjusted close to those of the previous diblockcopolymers (sample 3 and 4) owning a bicontinuous
3050 | Polym. Chem., 2014, 5, 3045–3052
morphology showed a rough phase separated morphology withdomains in micrometer size (see Fig. S12‡).
At a high iPS content (89 wt%, sample 6), the circumscriptionof the iP(E-alt-S) domains was observed, which were foundembedded in the iPS matrix with a shape approximately circularand an average size of around 35 nm (Fig. 5e and S10‡). Finally,an iPS homopolymer (sample 7) obtained using the samecatalyst and analyzed by TM-AFM conrms the expectedabsence of any specic nanoscale morphology as shown inFig. 5f and S11.‡ The analyzed thin lms were not thermal orsolvent annealed, thus presenting non-equilibrium morpho-logies. The analyses by small angle X-ray scattering (SAXS)conrmed the absence of regular distributions of these nano-structures (Fig. S13‡). The formation of these morphologiesclearly conrms although in an indirect manner, as a suitablecomplement of the NMR, GPC and TREF analyses, the obtain-ment of true block copolymers, excluding the formation ofpolymer blends.20
On the basis of these results and the thermal and X-rayanalyses, one can conclude that the two polymer segments, iPSand alternating E–S, are incompatible, i.e. each segment doesnot affect the other notwithstanding their tight chemical simi-larity, affording a material with two different phases.
Conclusions
At 0 �C the low polyinsertion rate of the styrene into the metal–carbon bond of the ansa zirconocene-based catalyst coupledwith the low termination rate allows the facile synthesis of
di-block copolymers where the two segments are the isotacticstyrene homosequence and alternating isotactic ethylene–styrene sequence. The synthetic procedure we exploited seemsexible enough to allow the achievement of tailor made furtherunprecedented architectures by playing with the feed condi-tions and the catalyst symmetry.
These copolymers were studied by X-ray diffraction, thermalanalysis by DSC, and solid state NMR that highlight the crys-tallinity due to packing of the two different stereoregularsequences.
The AFM analysis of specimens obtained through spin-coating shows different nanostructures, depending on thecopolymer composition, ranging from: (i) isolated domains ofiPS, with a size of about 30 nm, embedded in a matrix ofiP(E-alt-S); (ii) bicontinuous nanostructured phases; (iii) iso-lated domains of iP(E-alt-S), with a size of about 35 nm, sur-rounded by a matrix of iPS.
Acknowledgements
The authors thank Dr Ivano Immediata and Dr Vito Speranzafrom the Universita degli Studi di Salerno, Dr Marino Lavorgnaand Dr Andrea Sorrentino from the Consiglio Nazionale delleRicerche for technical assistance and useful discussions, and DrGiuseppe Ferrara and Dr Giorgio Nadalini from LyondellbasellPolyolens for TREFmeasurements. The work was supported bythe project PRIN 2010–2011 “Materiali Polimerici Nano-strutturati con strutture molecolari e cristalline mirate, pertecnologie avanzate e per l'ambiente”.
Notes and references
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I.1. HT GPC analysis iPS-b-iP(E-alt-S) diblock copolymers 2−5 of Table 1. ...................................... 3 Fig. S1. GPC chromatograms at 135 °C of: a) sample 2, b) sample 3, c) sample 4 and d) sample 5 of Table1. ................................................................................................................................. 3
II. TEMPERATURE RAISING ELUTION FRACTIONATION. ....................................................................... 4 II.1. TREF analysis of sample 6. .................................................................................................. 4
Fig. S2. Plot of TREF fractions for sample 6. ............................................................................... 4 II.2. 13C NMR analysis of TREF fractions of sample 6. ................................................................... 5
Fig. S3. 13C NMR spectra of: a) sample 6; b) TREF fraction collected at 30 °C containing the sample 6 (signals highlighted in red) and pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (added to the eluent as stabilizer); c) TREF fraction collected at 130 °C containing pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate). .............................................................. 5
III. ANALYSIS BY DIFFERENTIAL SCANNING CALORIMETRY. ................................................................. 6 III.1. Thermal behaviour of sample 2 annealed at 100 °C for 5 min. ................................................ 6
Fig. S4. DSC trace of sample 2 annealed at 100 °C for 5 min: 1st run (blue curve) and 2nd run (red curve).6 IV. ATOMIC FORCE MICROSCOPY ANALYSIS. ..................................................................................... 7
IV.1. AFM analysis of sample 1 of Table 1. ................................................................................... 7 Fig. S5. Height (a) and phase (b) 2D TM-AFM micrographs of sample 1 of Table 1 corresponding to the 3D micrographs in Fig. 5a. ........................................................................................................ 7
IV.2. AFM analysis of sample 2 of Table 1. ................................................................................... 8 Fig. S6. Height (a) and phase (b) 2D TM-AFM micrographs of sample 2 of Table 1 corresponding to the 3D micrographs in Fig. 5b. Dimension distribution analysis (c) of iPS domains in Figure (b) performed with Nanoscope Analysis v1.40 r2sr1 software from Bruker as shown in Figure (d). ............................ 8
IV.3. AFM analysis of sample 3 of Table 1. ................................................................................... 9 Fig. S7. Height (a) and phase (b) 2D TM-AFM micrographs of sample 3 of Table 1 corresponding to the 3D micrographs in Figure 5c. .................................................................................................... 9
IV.4. AFM analysis of sample 4 of Table 1. ................................................................................. 10 Fig. S8. Height (a) and phase (b) 2D TM-AFM micrographs of sample 4 of Table 1 corresponding to the 3D micrographs in Figure 5d. .................................................................................................. 10 Fig. S9. Height (a and c) and phase (b and d) TM-AFM micrographs a iPS-b-iP(E-alt-S) diblock copolymer sample 4, illustrating the large scale formation of bicontinuous phases. ............................ 11
IV.5. AFM analysis of sample 6 of Table 1. ................................................................................. 12 Fig. S10. Height (a) and phase (b) 2D TM-AFM micrographs of sample 6 of Table 1 corresponding to the 3D micrographs in Figure 5e. c) Dimension distribution analysis of iP(E-alt-S) domains in Figure (b) performed with Nanoscope Analysis v1.40 r2sr1 software from Bruker as shown in Figure d............... 12
IV.6. AFM analysis of iPS homopolymer. ................................................................................... 13 Fig. S11. Height (a) and phase (b) 2D TM-AFM micrographs of a thin film of iPS homopolymer (sample 7) corresponding to the 3D micrographs in Figure 5f. ................................................................... 13
IV.6. AFM analysis of iPS and iP(E-alt-S) solution blend. ............................................................. 14 Fig. S12. Height (a and c) and phase (b and d) TM-AFM micrographs of a solution blend of iPS homopolymer and iP(E-alt-S) alternate copolymer sample 1 (50:50 by weight), illustrating the large scale raw phase separation. ............................................................................................................. 14
V. SAXS ANALYSIS. .................................................................................................................. 15 Fig. S13. SAXS patterns of samples reported in Table 1. .............................................................. 15
II.2. 13C NMR analysis of TREF fractions of sample 6.
Fig. S3. 13C NMR spectra of: a) sample 6; b) TREF fraction collected at 30 °C containing the sample 6 (signals highlighted in red) and pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) (added to the eluent as stabilizer); c) TREF fraction collected at 130 °C containing pentaerythritol tetrakis(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate).
Fig. S6. Height (a) and phase (b) 2D TM-AFM micrographs of sample 2 of Table 1 corresponding to the 3D micrographs in Fig. 5b. Dimension distribution analysis (c) of iPS domains in Figure (b) performed with Nanoscope Analysis v1.40 r2sr1 software from Bruker as shown in Figure (d).
Fig. S9. Height (a and c) and phase (b and d) TM-AFM micrographs a iPS-b-iP(E-alt-S) diblock copolymer sample 4, illustrating the large scale formation of bicontinuous phases.
Fig. S10. Height (a) and phase (b) 2D TM-AFM micrographs of sample 6 of Table 1 corresponding to the 3D micrographs in Figure 5e. c) Dimension distribution analysis of iP(E-alt-S) domains in Figure (b) performed with Nanoscope Analysis v1.40 r2sr1 software from Bruker as shown in Figure d.
Fig. S11. Height (a) and phase (b) 2D TM-AFM micrographs of a thin film of iPS homopolymer (sample 7) corresponding to the 3D micrographs in Figure 5f.
IV.6. AFM analysis of iPS and iP(E-alt-S) solution blend.
Fig. S12. Height (a and c) and phase (b and d) TM-AFM micrographs of a solution blend of iPS homopolymer and iP(E-alt-S) alternate copolymer sample 1 (50:50 by weight), illustrating the large scale raw phase separation.
