**1.1. Materials, methods and instrumentations**

Polypropylene glycol (PPG, MW 1000) was dried under vacuum at 120 oC for 2 h. Tolylene diisocyanate (mixture 80/20 of 2,4- and 2,6- isomers) (TDI) was distilled under vacuum.

Diethylene glycol (DEG) was distilled under vacuum at 105 oC. Trimethylol propane (98%) (TMP) was dried under vacuum at 40-45 oC for 2-4 h. Dichloromethane (CH2Cl2), 1,4 dioxane and N,N- dimethylformamide (DMF) were distilled at 40 oC, 101 oC, 153 oC, respectively. The following chelate compounds of transition and rare-earth metals as PU modifier were used:

Bottom-Up Nanostructured Segmented Polyurethanes with Immobilized in situ Transition and Rare-Earth Metal Chelate Compounds – Polymer Topology – Structure and Properties Relationship 53

In metal chelate compounds used as PU modifier metal ions are already surrounded with organic ligands. This facilitates solvation of modifier in polymer. The listed above transition and rare-earth metal chelate compounds are commercial products (Aldrich). The heteroligand rare-earth metal compounds were synthesized by Professor Svetlana B. Meshkova's group (A. V. Bogatsky Physic-Chemical Institute of National Academy of Sciences of Ukraine, Odessa). Polyheteronuclear metal complexes of Cu (2+), Cd (2+), Zn (2+), Ni (2+) and Co (3+), described in (Skopenko et al., 1997; Vinogradova et al., 2002), were provided by Prof. V. Kokozay's goup (Kiev Taras Shevchenko University). Polyheteronuclear metal chelate compounds can realize unexpected coordination states of transition metal ions. That, in turn,

PUs were synthesized in two stages according to standard procedure described in detail elsewhere (Saunders&Frish,1968; Wirspza,1993) using PPG-1000 and TDI based prepolymer. DEG was used as chain extender to obtain LPU (Scheme 2). TMP was used as cross-linking agent to obtain CPU (Scheme 3). Metal chelate compounds were added into reaction mixture as solution in CH2Cl2, 1,4-dioxane or DMF to obtain the metal containing PUs with homogeneous distribution of modifier (from 0,5 to 5 %wt.) in polymer matrix. High ability of metal chelate compound to complex formation leads to enrichment of PU matrix with heteroligand macro complexes of 3d- and 4f-metal with prevalence of outer-sphere coordination of macro chains. Such macro complexes act like coordination linkages between

Thus, in the LPU (Scheme 2) in the presence of chelate metal compounds the "coordination

N H C O

O CH2 CH2 O CH2 CH2 O

m

n C O N H

H3C

can give new properties to a polymer formed in their presence.

polymer chains and form "coordination nodes" in PU (Scheme 1).

**Scheme 1.** The coordination junction of PUs networks.

N C O H

O CH3 CH2 CH O

nodes" can form.

H

**Scheme 2.** The general formula of LPU.

C N

O H3C

**Table 1.** The PU modified chelate compounds of transition and rare‐earth metals.

In metal chelate compounds used as PU modifier metal ions are already surrounded with organic ligands. This facilitates solvation of modifier in polymer. The listed above transition and rare-earth metal chelate compounds are commercial products (Aldrich). The heteroligand rare-earth metal compounds were synthesized by Professor Svetlana B. Meshkova's group (A. V. Bogatsky Physic-Chemical Institute of National Academy of Sciences of Ukraine, Odessa). Polyheteronuclear metal complexes of Cu (2+), Cd (2+), Zn (2+), Ni (2+) and Co (3+), described in (Skopenko et al., 1997; Vinogradova et al., 2002), were provided by Prof. V. Kokozay's goup (Kiev Taras Shevchenko University). Polyheteronuclear metal chelate compounds can realize unexpected coordination states of transition metal ions. That, in turn, can give new properties to a polymer formed in their presence.

PUs were synthesized in two stages according to standard procedure described in detail elsewhere (Saunders&Frish,1968; Wirspza,1993) using PPG-1000 and TDI based prepolymer. DEG was used as chain extender to obtain LPU (Scheme 2). TMP was used as cross-linking agent to obtain CPU (Scheme 3). Metal chelate compounds were added into reaction mixture as solution in CH2Cl2, 1,4-dioxane or DMF to obtain the metal containing PUs with homogeneous distribution of modifier (from 0,5 to 5 %wt.) in polymer matrix. High ability of metal chelate compound to complex formation leads to enrichment of PU matrix with heteroligand macro complexes of 3d- and 4f-metal with prevalence of outer-sphere coordination of macro chains. Such macro complexes act like coordination linkages between polymer chains and form "coordination nodes" in PU (Scheme 1).

**Scheme 1.** The coordination junction of PUs networks.

Thus, in the LPU (Scheme 2) in the presence of chelate metal compounds the "coordination nodes" can form.

**Scheme 2.** The general formula of LPU.

52 Polyurethane

Met

modifier were used:

R1 <sup>O</sup>

<sup>O</sup> CH3 <sup>2</sup>

O

O

O Eu

L4

Met

O

3

R2

R1

R2

3

1 2 31 23 *<sup>M</sup> k m npq r t et Met Met R R R Sol pqkm* ,,, ,,,; 1234 *nrt* ,, ,; 0 1 where Me2Ea = deprotonated residue of dimethyl aminoethanol Dea = doubly deprotonated residue of diethanolamine

**Table 1.** The PU modified chelate compounds of transition and rare‐earth metals.

R1

Diethylene glycol (DEG) was distilled under vacuum at 105 oC. Trimethylol propane (98%) (TMP) was dried under vacuum at 40-45 oC for 2-4 h. Dichloromethane (CH2Cl2), 1,4 dioxane and N,N- dimethylformamide (DMF) were distilled at 40 oC, 101 oC, 153 oC, respectively. The following chelate compounds of transition and rare-earth metals as PU

*(R=-CH3)* 

*(R = -OC2H5)*  Cu(eacac)2 - Copper (2+) ethyl acetoacetate *(R = --CF3).*  Cu(tfacac)2 - Copper (2+)trifluoro acetylacetonate

*(R1=R2=-CH3 )* 

*(R1 =-C(CH3)3 , R2 =-(CF2)2-CF3)*  Eu(fod)3 – Europium (3+) tris(6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionate) *(R1 =- thiophene , R2 =- CF3)*  Eu(TTA)3 – Europium (3+) thenoyltrifluoroacetonate

*(R1 =- thiophene , R2 =- CF3 ; L4= phen)*  Eu(TTA)3 phen – Europium (3+) tris(thenoyltrifluoroacetonate) phenantroline *(R1 =- thiophene , R2 =- CF3 ; L4= triphenylphosphine oxide)*  Eu(TTA)3 TPPO –Europium (3+) tris (thenoyltrifluoroacetonate) (triphenylphosphine oxide)

> *k*=2, *m*=1, n=0, *p*=3, *q*=3, r=0, *t*=1, R1=NCS, R2=Me2Ea, Sol= CH3CN [Cu2Zn(NCS)3(Me2Ea)3]CH3CN *k*=2, *m*=3,n=0, p=6, *q*=4, r=0, *t*=2, R1=Br, R2=Me2Ea, Sol= dmso [Cd2Cu3Br6(Me2Ea)4(dmso)2] *k*=1, *m*=2, *n*=2, *p*=3, *q*=4, r=4, t=0, R1= H2Dea, R2= NCS, R3= Dea [Ni(H2Dea)2][CoCu(Dea)2(H2Dea) (NCS)]2(NCS)2

Cu(acac)2 - Copper(2+) acetylacetonate Ni(acac)2 – Nickel(2+) acetylacetonate

Co(acac)3 – Cobalt (3+) acetylacetonate Cr(acac)3 – Chromium (3+) acetylacetonate Gd(acac)3 – Gadolinium (3+) acetylacetonate Nd(acac)3 – Neodymium (3+) acetylacetonate Er(acac)3 – Erbium (3+) acetylacetonate

In the metal containing CPU both the chemical linkages (Scheme 3) and the "coordination nodes" can form (Scheme 1).

**Scheme 3.** The fragment of PU network with cross‐linkage.

*Wide-angle X-ray scattering (WAXS)* profiles of studied samples were recorded on a Dron-4- 07 diffractometer with Ni-filtered Cu-Kα radiation and Debay-Sherer optical schema. Distance between PU atomic layers (*d*) was estimated using the Bragg equation:

$$
\lambda = 2d \sin \theta \tag{1}
$$

Bottom-Up Nanostructured Segmented Polyurethanes with Immobilized in situ Transition and Rare-Earth Metal Chelate Compounds – Polymer Topology – Structure and Properties Relationship 55

0 sg lg *γ γ* ,5 (1 cos ) *θ* (4)

1 1 *ε С С δ ωС ε ε δ* ' / ,t *<sup>о</sup>* g R and " ' t g (5)

M\* M' M",M' "/ ' " ,M" '/ ' " 2 2 2 2 *ε ε ε εε ε* (7)

*σ σ σ σ ωε σ ωε* \* ' ", ' " , " ', (6)

Z' M"/( C ), Z" M'/( C ) *ω ω* o o (8)

*The differential scanning calorimetry* in temperature interval from 223 to 750 K was performed using Perkin Elmer DSC 2 instrument with the IFA GmbH's software. The heating rate was

*Micro images* in light transmission were obtained using an optical microscope XY-B2 (NS Instr. Co.) equipped with digital video ocular ICM 532 and AMCAM/VIDCAP (Microsoft)

*The surface tension* of PUs (sg) was determined according to Elton's equation (Tavana et al., 2004) using measurement of contact wetting angle with ethyleneglycol (EG) as wetting

where sg and γlg are the surface tension on solid-gas and liquid-gas boundaries,

The mean value of γsg was calculated as average of 5 different measurements and error of

*The spectra of luminescence* were obtained using the luminescent spectrometer SDL-1 (LOMO) in an excitation by the mercury lamp. The emission of the most intensive line with the

*Two-electrode method measurements of conductivity* at a direct current (dc) were conducted using a Hiresta UP high resistivity meter (Mitsubishi Chemicals, Japan). A dc voltage of 10 V was applied across the sample thickness. The samples were dried over night in an oven at 40°C under vacuum and then kept in dried environment, for the elimination of any

*Dielectric relaxation analysis* was performed using dielectric spectrometer on the base on alternating current bridge R5083. *C*omplex dielectric permittivity, ε\* = ε' – iε'', of disc-like specimens (diameter: 20 mm) sandwiched between gold-coated brass electrodes was measured over the frequency window from 102 to 105 Hz in the temperature interval from -- 40 to 120 °С. They have been analyzed from the traditional point of view (Pathmanatham & Johari, 1990; Pissis & Kanapitsas, 1996). Additional formalisms such as: complex admittance

σ\*, electrical modules М\* and impedances Z', Z" were used according to formulas.

Со and С1 – are instrument and standard capacitor capacities, ω – cyclic frequency.

respectively; is the boundary wetting angle; solid is PU; liquid is EG.

measurements did not exceed the value of 0,5 mN/m.

maximum on 365 nm was selected with light filter UFS-2.

0,05-2 grad/min.

liquid at 20oC:

moisture effects.

image processing system.

where *λ* – the X-ray wave length (*λ* = 0,154 nm); θ - the diffraction maximum angular position, degrees.

*Small-angle X-ray scattering (SAXS)* profiles were recorded using KPM-1 X-ray camera (Kratky et al., 1966). The Schmidt's method (Schmidt & Hight, 1960) was used to smooth out the SAXS-profiles to point collimation. X-ray measurements are carried out using monochromatic Ni-filter of Cu-Kα radiation at temperature 22±2 оС. The Bragg's period of uniform electronic density scattering elements was estimated through the equation:

$$D = 2\pi \mid \mathfrak{q} \tag{2}$$

*The X-band EPR-spectra* were recorded at temperature 20оС using radio spectrometer РE-1306 equipped with frequency meter ChZ-54. The magnetic field was calibrated using 2, 2 diphenil-1-pycrilhydrazyl (DPPH) (g=2,0036) and ions of Mn(2+) in MgO matrix (g=2,0015).

Stable nitroxide radical 2,2,6,6-tetramethylpiperidinyl-1-oxy (ТЕМPО) was used as paramagnetic spin probe (SP). Nitroxide SP was introduced into PU films via diffusion of its saturated vapor at 30oC for 2 hours with subsequent keeping at 20oC for 24 hours.

Correlation time () of SP rotational diffusion in the range of its fast motion (10-11 < <10-9s) was calculated according (Vasserman & Kovarskii, 1986) as follows:

$$\tau = 6,65\Delta H\_{\text{(+1)}}(\sqrt{\left(I\_{+1}\left/I\_{-1}\right)}-1)\times 10^{-10}\text{c}}.\tag{3}$$

where Н (+1) – is width of the low-field- component of ТЕМPО EPR-spectrum, *І+1* and *І–1* are intensities of low-field and high-field components of the spectrum, respectively.

*The differential scanning calorimetry* in temperature interval from 223 to 750 K was performed using Perkin Elmer DSC 2 instrument with the IFA GmbH's software. The heating rate was 0,05-2 grad/min.

54 Polyurethane

nodes" can form (Scheme 1).

position, degrees.

CH2 OCN

O

O

O

**Scheme 3.** The fragment of PU network with cross‐linkage.

CH2 O C N

C2H5 C CH2 OCN

H

H3C

H

H3C

H3C

H

In the metal containing CPU both the chemical linkages (Scheme 3) and the "coordination

O CH3 CH2 CH O

O CH3 CH2 CH O

O CH3

*Wide-angle X-ray scattering (WAXS)* profiles of studied samples were recorded on a Dron-4- 07 diffractometer with Ni-filtered Cu-Kα radiation and Debay-Sherer optical schema.

where *λ* – the X-ray wave length (*λ* = 0,154 nm); θ - the diffraction maximum angular

*Small-angle X-ray scattering (SAXS)* profiles were recorded using KPM-1 X-ray camera (Kratky et al., 1966). The Schmidt's method (Schmidt & Hight, 1960) was used to smooth out the SAXS-profiles to point collimation. X-ray measurements are carried out using monochromatic Ni-filter of Cu-Kα radiation at temperature 22±2 оС. The Bragg's period of

> *D q* 2 /

*The X-band EPR-spectra* were recorded at temperature 20оС using radio spectrometer РE-1306 equipped with frequency meter ChZ-54. The magnetic field was calibrated using 2, 2 diphenil-1-pycrilhydrazyl (DPPH) (g=2,0036) and ions of Mn(2+) in MgO matrix (g=2,0015). Stable nitroxide radical 2,2,6,6-tetramethylpiperidinyl-1-oxy (ТЕМPО) was used as paramagnetic spin probe (SP). Nitroxide SP was introduced into PU films via diffusion of its

Correlation time () of SP rotational diffusion in the range of its fast motion (10-11 < <10-9s)

where Н (+1) – is width of the low-field- component of ТЕМPО EPR-spectrum, *І+1* and *І–1* -

are intensities of low-field and high-field components of the spectrum, respectively.

uniform electronic density scattering elements was estimated through the equation:

saturated vapor at 30oC for 2 hours with subsequent keeping at 20oC for 24 hours.

was calculated according (Vasserman & Kovarskii, 1986) as follows:

n C O N H

n C O N H

CH 2 CH O

H3C

H3C

H3C

*λ* 2*d* sin*θ* (1)

(2)

10 1 11 6 65 1 10 ( ) *<sup>τ</sup>* , (( / ) ) , *H II c* (3)

H N O C n

N H C O O

N H C O O

O O C H N

N C O H

N C O H

H N C O

Distance between PU atomic layers (*d*) was estimated using the Bragg equation:

*Micro images* in light transmission were obtained using an optical microscope XY-B2 (NS Instr. Co.) equipped with digital video ocular ICM 532 and AMCAM/VIDCAP (Microsoft) image processing system.

*The surface tension* of PUs (sg) was determined according to Elton's equation (Tavana et al., 2004) using measurement of contact wetting angle with ethyleneglycol (EG) as wetting liquid at 20oC:

$$\gamma\_{\rm sg} = 0.5 \gamma\_{\rm lg} (1 + \cos \theta) \tag{4}$$

where sg and γlg are the surface tension on solid-gas and liquid-gas boundaries, respectively; is the boundary wetting angle; solid is PU; liquid is EG.

The mean value of γsg was calculated as average of 5 different measurements and error of measurements did not exceed the value of 0,5 mN/m.

*The spectra of luminescence* were obtained using the luminescent spectrometer SDL-1 (LOMO) in an excitation by the mercury lamp. The emission of the most intensive line with the maximum on 365 nm was selected with light filter UFS-2.

*Two-electrode method measurements of conductivity* at a direct current (dc) were conducted using a Hiresta UP high resistivity meter (Mitsubishi Chemicals, Japan). A dc voltage of 10 V was applied across the sample thickness. The samples were dried over night in an oven at 40°C under vacuum and then kept in dried environment, for the elimination of any moisture effects.

*Dielectric relaxation analysis* was performed using dielectric spectrometer on the base on alternating current bridge R5083. *C*omplex dielectric permittivity, ε\* = ε' – iε'', of disc-like specimens (diameter: 20 mm) sandwiched between gold-coated brass electrodes was measured over the frequency window from 102 to 105 Hz in the temperature interval from -- 40 to 120 °С. They have been analyzed from the traditional point of view (Pathmanatham & Johari, 1990; Pissis & Kanapitsas, 1996). Additional formalisms such as: complex admittance σ\*, electrical modules М\* and impedances Z', Z" were used according to formulas.

$$\boldsymbol{\varepsilon}^{\prime} = \mathbf{C}\_{1} \; / \, \mathbf{C}\_{o} \; \text{tg}\boldsymbol{\delta} = \boldsymbol{\alpha} \mathbf{R} \mathbf{C}\_{1} \mathbf{n} \mathbf{n} \; \text{d} \; \text{e}^{\prime} = \boldsymbol{\varepsilon}^{\prime} \cdot \mathbf{t} \mathbf{g} \boldsymbol{\delta} \tag{5}$$

$$
\sigma^\* = \sigma' + \sigma''\prime\prime \; \sigma' = \alpha \varepsilon''\prime\prime \; \sigma'' = \alpha \varepsilon\prime\prime \tag{6}
$$

$$\mathbf{M}^\* = \mathbf{M}' + \mathbf{M}'' , \mathbf{M}' = \varepsilon'' / \left(\varepsilon'^2 + \varepsilon''^2\right) , \mathbf{M}'' = \varepsilon' / \left(\varepsilon'^2 + \varepsilon''^2\right) \tag{7}$$

$$
\hbar Z' = \mathbf{M}'' / (\omega \mathbb{C}\_{\mathbf{o}})\_{\prime} \, Z'' = \mathbf{M}' / (\omega \mathbb{C}\_{\mathbf{o}}) \tag{8}
$$

Со and С1 – are instrument and standard capacitor capacities, ω – cyclic frequency.

*The electron spectra* of the copper (2+) containing PU films and of copper (2+) chelate compounds solutions in dichloromethane (c = 10-2M) in the ultra-violet and visible region were recorded using the spectrometer Specord UV-VIS.

Bottom-Up Nanostructured Segmented Polyurethanes with Immobilized in situ Transition and Rare-Earth Metal Chelate Compounds – Polymer Topology – Structure and Properties Relationship 57

System 2θ, degree *d*, nm q*m*, nm-1 D, nm CPU-0 20 0.44 1.7 3.7 CPU-0,5% Eu(fod)3 20 0.44 1.7 3.7 CPU-1% Eu(fod)3 19.9 0.45 1.76 3.6 CPU-3% Eu(fod)3 19.9 0.45 1.76 3.6 CPU-5% Eu(fod)3 19.4 0.46 2.0 3.1 LPU-0 20 0.44 1.7 3.7

LPU-0,5% EEu(fod)3 20 0.44 1.7 3.7 LPU-1% Eu(fod)3 20 0.44 1.9 3.3 LPU-3% Eu(fod)3 20 0.44 1.8 3.5 LPU-5% Eu(fod)3 20 0.44 1.9 3.4

**Figure 2.** The SAXS intensity profiles of CPU (a) and LPU (b): metal-free (1), modified with 0,5% (2), 1%

Analysis according (Porod, 1982) of heterogeneity range (*lp*) and average diameter (*l1, l2*) of different scattering elements in CPU-0, CPU-Cr and CPU-Со indicate existence of two types of nanosize heterogeneities in the bulk of PU. The first one (with *l1* < *D* ) is inherent to segmented PU. The second one (with *l2* > *D*) is generated in the presence of transition metal chelate compound. We can define the latter structures as "metal chelate compound – polyurethane" complexes with polymer chains as macro ligands (Kozak et al., 2006;

Thus, the immobilization *in situ* of metal chelate compounds in polyurethane is accompanied with enrichment of polymer matrix with the nanosize heteroligand macro complexes of metal formed simultaneously with organic nanosize structures typical for

*2* θ - the diffraction maximum angular position, degrees; *d* – distance between PU atomic layers from WAXS, nm; *qm -* value at maximum intensity of *I*(*q*) relationship, nm-1;

(3), 3% (4) and 5% (5) Eu(fod)3.

Nizelskii & Kozak, 2006) (Scheme 1).

metal-free polymer.

**Table 2.** X-ray structural characteristic of LPU and CPU

*D* - changeover period of uniform electronic density scattering elements from SAXS, nm.

*The quasi-elastic neutron scattering* (QENS) was recorded using the multi detector spectrometer "NURMEN" on the atomic reactor ВВР-М (The institute of the nuclear research of the NAS of Ukraine). The self-diffusion of chloform used as low molecular probe liquid in swelled PU films was analyzed.
