- Email: [email protected]
Evidence of cooperativity length anisotropy in drawn polymers
Materials Letters 128 (2014) 12–14
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
Evidence of cooperativity length anisotropy in drawn polymers Florian Hamonic, Allisson Saiter n, Eric Dargent AMME-LECAP EA4528 International Laboratory, Université de Rouen, 76801 Saint Etienne du Rouvray, France
art ic l e i nf o
a b s t r a c t
Article history: Received 13 March 2014 Accepted 18 April 2014 Available online 24 April 2014
The goal is to quantify the respective influence on relaxation dynamics of the molecular orientation and of the crystallinity in uniaxially drawn polyethylene terephthalate and poly(ethylene glycolco-cyclohexane-1,4-dimethanol terephthalate) films, the last one presenting a lower ability to crystallize under drawing. Combining Temperature Modulated Differential Scanning Calorimetry and Dynamical Mechanical Analysis investigations we evidenced that cooperativity length scale becomes anisotropic with the molecular orientation induced by drawing. & 2014 Elsevier B.V. All rights reserved.
Keywords: Cooperativity Strain Induced Crystallization TMDSC DMA
1. Introduction The evolution of the molecular mobility and of the cooperativity length in glass forming liquids with time and temperature is still attracting the interest of researchers [1–3]. The idea of a growing characteristic length scale influencing relaxation dynamics of glass formers [4–6] has been introduced with the concept of Cooperative Rearranging Region (CRR). The CRR is defined as the smallest amorphous domain where conformational rearrangements may occur without causing rearrangements in the surrounding [7].The cooperativity length can be estimated from calorimetric investigations on the basis of the Donth's approach [8]: !1=3 ð1=C p Þglass ð1=C p Þliquid 2 ξT α ¼ kB T α ð1Þ ρðδTÞ2 where Tα is the glass transition temperature, δT the mean temperature fluctuation related to the glass transition of an average CRR, ρ is the glass density, and kB the Boltzmann constant. Many studies focused on the cooperativity length (or dynamic heterogeneity) at the glass transition for systems where relaxation processes in the amorphous phase are affected by different physical or chemical routes: the presence of crystalline phases [9–12], the presence of nano-inclusion [13–16], a pure geometric confinement as in ultrathin films and multilayers [17–20]. Note that some studies are based on Dynamical Mechanical Analysis (DMA) investigations to characterize the cooperativity length in the amorphous phase [21,22]. The influence of a structural anisotropy, as that induced by drawing, on the molecular mobility is not yet a topic well explored. In previous works [23,24], combining Temperature n
Corresponding author. Tel.: þ 332 32 95 50 86; fax: þ332 32 95 50 82. E-mail address: [email protected] (A. Saiter).
http://dx.doi.org/10.1016/j.matlet.2014.04.090 0167-577X/& 2014 Elsevier B.V. All rights reserved.
Modulated Differential Scanning Calorimetry (TMDSC) and DMA investigations, we showed for the first time that in PET the CRR size at Tg becomes anisotropic with molecular orientation induced by drawing. By studying only PET films it was not possible to quantify the respective influence of the molecular orientation and of the crystallinity on the cooperativity evolution. Indeed, drawing a polymer can change the macromolecular orientation inducing chain alignment and even Strain Induced Crystallization (SIC) [25–27]. In this work, we present data of uniaxially drawn polyethylene terephthalate (PET) and poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) (PETg) films. The greatest interest in studying the PET and PETg materials is that they exhibit a similar chemical structure [12], similar parameters characterizing the glass transition [12,28,29] (see Table 1), but very different ability to crystallize [30]. Furthermore, it has been recently proved that the macromolecular orientation is equivalent in these two drawn systems [31,32]. Thus, it seems possible to quantify the respective influence of the molecular orientation and the crystallinity on relaxation dynamics. This is the reason for which we propose to compare PET and PETg and also to increase the investigated draw ratio, λ, range in comparison to previous works. As far as we know, this is the first time that such a study is presented.
2. Materials and methods PET material is obtained from a film extruded by Carolex Co. 1 The number-average molecular weight is Mn ¼ 31; 000 g mol . The initial film is isotropic and the crystallinity degree is negligible [27]. The PETg used (6763 from Tennessee Eastman Co.) is an amorphous copolymer, consisting of cyclohexane dimethanol, ethylene glycol and terephthalic acid with a molar ratio of
F. Hamonic et al. / Materials Letters 128 (2014) 12–14
13
Table 1 Values of Tg, ΔCp(Tg), fragility index m, and crystallinity degree Xcmax reached by drawing.
PET PETg
800 700
Tg (K)
ΔCp(Tg) (J/K g)
M
Xcmax (%)
346 7 0.5 345 7 0.5
0.29 7 0.02 0.28 7 0.02
1607 16 1407 15
357 1 77 1
λ l longitudinal λ t transversal λl = 3
600 Loss modulus (MPa)
PET
λl = 5 λl = 1
500
λt = 1
400
λt = 3
300
λt = 5
200 100 0 40
50
60
70
80
90
100
110
120
130
140
150
Temperature (°C) 800 700
λ l longitudinal λ t transversal
PETg
Loss modulus (MPa)
λl = 6
λt = 6
600 500 400
λ l = 4.4
λl = 1
300
λt = 1
200 100
λ t = 4.4
0 40
50
60
70
80
90
100
110
120
130
140
150
Temperature (°C)
Fig. 1. Loss modulus data for PET (top) and for PETg (bottom) as a function of temperature.
Fig. 2. Cooperativity length evolution as a function of λ and for different excitations (longitudinal or transversal) for PET (top) and PETg (bottom), obtained from DMA and BDS experiments.
3. Results and discussion approximately 1: 2: 3. The number-average molecular weight is 1 Mn ¼ 26; 000 g mol . Before drawing, PET and PETg films are kept in the heating chamber of a tensile machine at 100 1C for 15 min. The films are then uniaxially drawn at 100 1C with a strain rate of 0.14 s 1. After drawing the films are cold air-quenched down to room temperature thus freezing their structural state. The draw ratio ranges studied in this work are 1 rλ r6.6 for PET and 1 rλr 7.6 for PETg. Temperature modulated differential scanning calorimetry: TMDSC experiments are performed in a TA DSC 2920 apparatus. The experiments are performed with “Heat-Iso” mode (oscillation amplitude of 0.318 K, oscillation period of 60 s and heating rate of 2 K/min). Calibration procedure is described elsewhere [23]. Some results are given in Table 1 and the experimental curves are shown in Ref. [32] for interested readers. Dynamical mechanical analysis: DMA measurements are performed on TA Q800 instrument in tension mode. Calibration procedure is described elsewhere [23]. Measurements are carried out for temperatures ranging from 40 1C to 150 1C with a heating rate of 2 1C min 1 under air atmosphere. The oscillation amplitude is 15 mm with a frequency of 1 Hz. Two measurement series are performed on each sample corresponding to two stress directions. The first one is the draw direction (called longitudinal direction), and the second one corresponds to the in-plane normal direction of the draw (called transversal direction).
The method for calculating the cooperatity length from TMDSC and DMA experiments is already described in previous works [23,24] and not reported here. δT is estimated from loss modulus spectra and it is proportional to the width at the middle height of the loss modulus peaks. As clearly shown in Fig. 1, this width varies with the draw ratio and the draw direction (longitudinal or transversal direction). For PET (Fig. 2 top) the cooperativity length is the same for longitudinal and transversal drawing directions for λ¼ 1 and for λZ 4. To verify that these results are consistent with those obtained from Broadband Dielectric Spectroscopy (BDS) analysis for the same excitation frequency (1 Hz), we added some results obtained from this technique [12]. For 1 oλ o4 a difference between the transversal and the longitudinal excitation is experimentally observed. For PETg (Fig. 2 bottom) the difference between the transversal and the longitudinal excitation exists for 1 oλo 6. To quantify this difference, we estimated the relative cooperativity length variation ΔξTα defined as: ΔξTα ¼
ξTα ðtransÞ ξTα ðlongÞ ξTα ðtransÞ
ð2Þ
where ξTα(trans) is the cooperativity length obtained from the transversal excitation, and ξTα(long) from the longitudinal excitation. The ΔξΤα evolution with λ is presented in Fig. 3. For PET and PETg
14
F. Hamonic et al. / Materials Letters 128 (2014) 12–14
uniaxially drawn PET and PETg films. The comparison is worth to be done because the two materials have a significant difference in terms of ability to crystallize and a similar ability in terms of macromolecular orientation. These two systems show the same behavior in terms of anisotropy of the cooperativity length, putting in evidence that this anisotropy is directly linked to the macromolecular orientation induced by the drawing procedure.
References
Fig. 3. Relative variation of cooperativity length as a function of λ for PET and PETg.
systems the trend is similar: the anisotropy is nil for λ ¼1, increases up to a maximum and then decreases. In order to understand the physical meaning of the anisotropy appearance in terms of cooperativity length, we compare the changes in ΔξTα values with the microstructure evolution of the samples: – For 1r λr2.3 for PET and 1 rλ r3.6 for PETg, the crystallinity degree is nil or very low. Upon drawing, macromolecules start to be oriented [32]. The loss modulus curves corresponding to the relaxation of the oriented amorphous phase are different between longitudinal and transversal excitations, thus ΔξΤα increases. – For PET and PETg ΔξΤα reaches a maximum corresponding to a drastic change in terms of microstructure: the SIC phase appearance at the critical draw ratio λc [23,24]. – For λZλc, there is a strong coupling between crystallites and oriented amorphous phase, even if the crystallite amount is low (as for PETg). In this case only the isotropic amorphous phase can relax at Tg, implying a decrease of the anisotropy. Note that the lower amount of crystallites in PETg than in PET implies greater CRR size able to relax at Tg (see Fig. 2) [23,24]. Since the crystallinity degree is very different for the two systems, we can assume that the anisotropy is directly correlated to the macromolecular orientation. 4. Conclusion In this work we studied the respective influence on relaxation dynamics of the molecular orientation and of the crystallinity in
[1] Sharifi S, Capaccioli S, Lucchesi M, Rolla P, Prevosto D. J Chem Phys 2011;134:044510. [2] Krutyeva M, Wischnewski A, Monkenbusch M. Phys Rev Lett 2013;110 (10):108303. [3] Zardalidis G, Floudas G. Macromolecules 2012;45(15):6272–80. [4] Saiter A, Delbreilh L, Couderc H, Arabeche K, Schonhals A, Saiter JM. Phys Rev E: Stat Nonlinear Soft Matter Phys 2010;81(4):041805. [5] Lacevic N, Starr FW, Schroder TB, Glotzer SC. J Chem Phys 2003;119 (14):7372–87. [6] Tarjus G, Kivelson SA, Nussinov Z, Viot P. J Phys Condens Matter 2005;17(50): R1143–R1182. [7] Adam G, Gibbs JH. J Chem Phys 1965;43(1):139. [8] Donth E. J Non-Cryst Solids 1982;53:325. [9] Capsal JF, Dantras E, Lacabanne C. J Non-Cryst Solids 2013;363:20–5. [10] Saiter A, Delpouve N, Dargent E, Saiter JM. Eur Polym J 2007;43(11):4675–82. [11] Delpouve N, Saiter A, Dargent E. Eur Polym J 2011;47:2414–23. [12] Hamonic F, Saiter A, Prevosto D, Dargent E, Saiter JM. AIP Conf Proc 2012;1459:211. [13] Saiter A, Couderc H, Grenet J. J Therm Anal Calorim 2007;88(2):483. [14] Bergman R, Swenson J, Borjesson L, Jacobsson P. J Chem Phys 2000;113 (1):357–63. [15] Couderc H, Saiter A, Grenet J, Saiter JM. Physica B 2011;406(14):2908–13. [16] Saiter A, Prevosto D, Passaglia E, Couderc H, Delbreilh L, Saiter JM. Phys Rev E: Stat Nonlinear Soft Matter Phys 2013;88:7. [17] Nguyen HK, Labardi M, Lucchesi M, Rolla P, Prevosto D. Macromolecules 2013;46(2):555–61. [18] Zhang C, Guo YL, Priestley RD. J Polym Sci, Part B: Polym Phys 2013;51 (7):574–86. [19] Arabeche K, Delbreilh L, Adhikari R, Michler GH, Hiltner A, Baer E, et al. Polymer 2102; 53: 1355-1361. [20] Arabeche K, Delbreilh L, Saiter JM, Michler GH, Adhikari R, Baer E. Polymer 2014. http://dx.doi.org/10.1016/j.polymer.2014.02.006. [21] Wu J, Huang G, Qu L, Zheng J. J Non-Cryst Solids 2009;355:1755–9. [22] Capsal JF, Pousserot C, Dantras E, Dandurand J, Lacabanne C. Polymer 2010;51:5207–11. [23] Delpouve N, Lixon C, Saiter A, Dargent E, Grenet J. J Therm Anal Calorim 2009;97(2):541–6. [24] Lixon C, Delpouve N, Saiter A, Dargent E, Grohens Y. Eur Polym J 2008;44 (11):3377–84. [25] Delpouve N, Stoclet G, Saiter A, Dargent E, Marais S. J Phys Chem B 2012;116:4615. [26] Chaaria F, Chaouchea M, Doucet J. Polymer 2003;44:473. [27] Dargent E, Bureau E, Delbreilh L, Zumailan A, Saiter JM. Polymer 2005;46:3090. [28] Saiter A, Dargent E, Saiter JM, Grenet J. J Non-Cryst Solids 2008;354:345–9. [29] Couderc H, Saiter A, Grenet J, Saiter JM, Boiteux G, Nikaj E, et al. Polym Eng Sci 2009;49:836–43. [30] Kattan M, Dargent E, Ledru J, Grenet J. J Appl Polym Sci 2001;81:3405–12. [31] Hamonic F PhD thesis. University of Rouen, France; 2012. [32] Hamonic F, Miri V, Saiter A, Dargent E. Eur Polym J 2014 (accepted).
Contents lists available at ScienceDirect
Materials Letters journal homepage: www.elsevier.com/locate/matlet
Evidence of cooperativity length anisotropy in drawn polymers Florian Hamonic, Allisson Saiter n, Eric Dargent AMME-LECAP EA4528 International Laboratory, Université de Rouen, 76801 Saint Etienne du Rouvray, France
art ic l e i nf o
a b s t r a c t
Article history: Received 13 March 2014 Accepted 18 April 2014 Available online 24 April 2014
The goal is to quantify the respective influence on relaxation dynamics of the molecular orientation and of the crystallinity in uniaxially drawn polyethylene terephthalate and poly(ethylene glycolco-cyclohexane-1,4-dimethanol terephthalate) films, the last one presenting a lower ability to crystallize under drawing. Combining Temperature Modulated Differential Scanning Calorimetry and Dynamical Mechanical Analysis investigations we evidenced that cooperativity length scale becomes anisotropic with the molecular orientation induced by drawing. & 2014 Elsevier B.V. All rights reserved.
Keywords: Cooperativity Strain Induced Crystallization TMDSC DMA
1. Introduction The evolution of the molecular mobility and of the cooperativity length in glass forming liquids with time and temperature is still attracting the interest of researchers [1–3]. The idea of a growing characteristic length scale influencing relaxation dynamics of glass formers [4–6] has been introduced with the concept of Cooperative Rearranging Region (CRR). The CRR is defined as the smallest amorphous domain where conformational rearrangements may occur without causing rearrangements in the surrounding [7].The cooperativity length can be estimated from calorimetric investigations on the basis of the Donth's approach [8]: !1=3 ð1=C p Þglass ð1=C p Þliquid 2 ξT α ¼ kB T α ð1Þ ρðδTÞ2 where Tα is the glass transition temperature, δT the mean temperature fluctuation related to the glass transition of an average CRR, ρ is the glass density, and kB the Boltzmann constant. Many studies focused on the cooperativity length (or dynamic heterogeneity) at the glass transition for systems where relaxation processes in the amorphous phase are affected by different physical or chemical routes: the presence of crystalline phases [9–12], the presence of nano-inclusion [13–16], a pure geometric confinement as in ultrathin films and multilayers [17–20]. Note that some studies are based on Dynamical Mechanical Analysis (DMA) investigations to characterize the cooperativity length in the amorphous phase [21,22]. The influence of a structural anisotropy, as that induced by drawing, on the molecular mobility is not yet a topic well explored. In previous works [23,24], combining Temperature n
Corresponding author. Tel.: þ 332 32 95 50 86; fax: þ332 32 95 50 82. E-mail address: [email protected] (A. Saiter).
http://dx.doi.org/10.1016/j.matlet.2014.04.090 0167-577X/& 2014 Elsevier B.V. All rights reserved.
Modulated Differential Scanning Calorimetry (TMDSC) and DMA investigations, we showed for the first time that in PET the CRR size at Tg becomes anisotropic with molecular orientation induced by drawing. By studying only PET films it was not possible to quantify the respective influence of the molecular orientation and of the crystallinity on the cooperativity evolution. Indeed, drawing a polymer can change the macromolecular orientation inducing chain alignment and even Strain Induced Crystallization (SIC) [25–27]. In this work, we present data of uniaxially drawn polyethylene terephthalate (PET) and poly(ethylene glycol-co-cyclohexane-1,4-dimethanol terephthalate) (PETg) films. The greatest interest in studying the PET and PETg materials is that they exhibit a similar chemical structure [12], similar parameters characterizing the glass transition [12,28,29] (see Table 1), but very different ability to crystallize [30]. Furthermore, it has been recently proved that the macromolecular orientation is equivalent in these two drawn systems [31,32]. Thus, it seems possible to quantify the respective influence of the molecular orientation and the crystallinity on relaxation dynamics. This is the reason for which we propose to compare PET and PETg and also to increase the investigated draw ratio, λ, range in comparison to previous works. As far as we know, this is the first time that such a study is presented.
2. Materials and methods PET material is obtained from a film extruded by Carolex Co. 1 The number-average molecular weight is Mn ¼ 31; 000 g mol . The initial film is isotropic and the crystallinity degree is negligible [27]. The PETg used (6763 from Tennessee Eastman Co.) is an amorphous copolymer, consisting of cyclohexane dimethanol, ethylene glycol and terephthalic acid with a molar ratio of
F. Hamonic et al. / Materials Letters 128 (2014) 12–14
13
Table 1 Values of Tg, ΔCp(Tg), fragility index m, and crystallinity degree Xcmax reached by drawing.
PET PETg
800 700
Tg (K)
ΔCp(Tg) (J/K g)
M
Xcmax (%)
346 7 0.5 345 7 0.5
0.29 7 0.02 0.28 7 0.02
1607 16 1407 15
357 1 77 1
λ l longitudinal λ t transversal λl = 3
600 Loss modulus (MPa)
PET
λl = 5 λl = 1
500
λt = 1
400
λt = 3
300
λt = 5
200 100 0 40
50
60
70
80
90
100
110
120
130
140
150
Temperature (°C) 800 700
λ l longitudinal λ t transversal
PETg
Loss modulus (MPa)
λl = 6
λt = 6
600 500 400
λ l = 4.4
λl = 1
300
λt = 1
200 100
λ t = 4.4
0 40
50
60
70
80
90
100
110
120
130
140
150
Temperature (°C)
Fig. 1. Loss modulus data for PET (top) and for PETg (bottom) as a function of temperature.
Fig. 2. Cooperativity length evolution as a function of λ and for different excitations (longitudinal or transversal) for PET (top) and PETg (bottom), obtained from DMA and BDS experiments.
3. Results and discussion approximately 1: 2: 3. The number-average molecular weight is 1 Mn ¼ 26; 000 g mol . Before drawing, PET and PETg films are kept in the heating chamber of a tensile machine at 100 1C for 15 min. The films are then uniaxially drawn at 100 1C with a strain rate of 0.14 s 1. After drawing the films are cold air-quenched down to room temperature thus freezing their structural state. The draw ratio ranges studied in this work are 1 rλ r6.6 for PET and 1 rλr 7.6 for PETg. Temperature modulated differential scanning calorimetry: TMDSC experiments are performed in a TA DSC 2920 apparatus. The experiments are performed with “Heat-Iso” mode (oscillation amplitude of 0.318 K, oscillation period of 60 s and heating rate of 2 K/min). Calibration procedure is described elsewhere [23]. Some results are given in Table 1 and the experimental curves are shown in Ref. [32] for interested readers. Dynamical mechanical analysis: DMA measurements are performed on TA Q800 instrument in tension mode. Calibration procedure is described elsewhere [23]. Measurements are carried out for temperatures ranging from 40 1C to 150 1C with a heating rate of 2 1C min 1 under air atmosphere. The oscillation amplitude is 15 mm with a frequency of 1 Hz. Two measurement series are performed on each sample corresponding to two stress directions. The first one is the draw direction (called longitudinal direction), and the second one corresponds to the in-plane normal direction of the draw (called transversal direction).
The method for calculating the cooperatity length from TMDSC and DMA experiments is already described in previous works [23,24] and not reported here. δT is estimated from loss modulus spectra and it is proportional to the width at the middle height of the loss modulus peaks. As clearly shown in Fig. 1, this width varies with the draw ratio and the draw direction (longitudinal or transversal direction). For PET (Fig. 2 top) the cooperativity length is the same for longitudinal and transversal drawing directions for λ¼ 1 and for λZ 4. To verify that these results are consistent with those obtained from Broadband Dielectric Spectroscopy (BDS) analysis for the same excitation frequency (1 Hz), we added some results obtained from this technique [12]. For 1 oλ o4 a difference between the transversal and the longitudinal excitation is experimentally observed. For PETg (Fig. 2 bottom) the difference between the transversal and the longitudinal excitation exists for 1 oλo 6. To quantify this difference, we estimated the relative cooperativity length variation ΔξTα defined as: ΔξTα ¼
ξTα ðtransÞ ξTα ðlongÞ ξTα ðtransÞ
ð2Þ
where ξTα(trans) is the cooperativity length obtained from the transversal excitation, and ξTα(long) from the longitudinal excitation. The ΔξΤα evolution with λ is presented in Fig. 3. For PET and PETg
14
F. Hamonic et al. / Materials Letters 128 (2014) 12–14
uniaxially drawn PET and PETg films. The comparison is worth to be done because the two materials have a significant difference in terms of ability to crystallize and a similar ability in terms of macromolecular orientation. These two systems show the same behavior in terms of anisotropy of the cooperativity length, putting in evidence that this anisotropy is directly linked to the macromolecular orientation induced by the drawing procedure.
References
Fig. 3. Relative variation of cooperativity length as a function of λ for PET and PETg.
systems the trend is similar: the anisotropy is nil for λ ¼1, increases up to a maximum and then decreases. In order to understand the physical meaning of the anisotropy appearance in terms of cooperativity length, we compare the changes in ΔξTα values with the microstructure evolution of the samples: – For 1r λr2.3 for PET and 1 rλ r3.6 for PETg, the crystallinity degree is nil or very low. Upon drawing, macromolecules start to be oriented [32]. The loss modulus curves corresponding to the relaxation of the oriented amorphous phase are different between longitudinal and transversal excitations, thus ΔξΤα increases. – For PET and PETg ΔξΤα reaches a maximum corresponding to a drastic change in terms of microstructure: the SIC phase appearance at the critical draw ratio λc [23,24]. – For λZλc, there is a strong coupling between crystallites and oriented amorphous phase, even if the crystallite amount is low (as for PETg). In this case only the isotropic amorphous phase can relax at Tg, implying a decrease of the anisotropy. Note that the lower amount of crystallites in PETg than in PET implies greater CRR size able to relax at Tg (see Fig. 2) [23,24]. Since the crystallinity degree is very different for the two systems, we can assume that the anisotropy is directly correlated to the macromolecular orientation. 4. Conclusion In this work we studied the respective influence on relaxation dynamics of the molecular orientation and of the crystallinity in
[1] Sharifi S, Capaccioli S, Lucchesi M, Rolla P, Prevosto D. J Chem Phys 2011;134:044510. [2] Krutyeva M, Wischnewski A, Monkenbusch M. Phys Rev Lett 2013;110 (10):108303. [3] Zardalidis G, Floudas G. Macromolecules 2012;45(15):6272–80. [4] Saiter A, Delbreilh L, Couderc H, Arabeche K, Schonhals A, Saiter JM. Phys Rev E: Stat Nonlinear Soft Matter Phys 2010;81(4):041805. [5] Lacevic N, Starr FW, Schroder TB, Glotzer SC. J Chem Phys 2003;119 (14):7372–87. [6] Tarjus G, Kivelson SA, Nussinov Z, Viot P. J Phys Condens Matter 2005;17(50): R1143–R1182. [7] Adam G, Gibbs JH. J Chem Phys 1965;43(1):139. [8] Donth E. J Non-Cryst Solids 1982;53:325. [9] Capsal JF, Dantras E, Lacabanne C. J Non-Cryst Solids 2013;363:20–5. [10] Saiter A, Delpouve N, Dargent E, Saiter JM. Eur Polym J 2007;43(11):4675–82. [11] Delpouve N, Saiter A, Dargent E. Eur Polym J 2011;47:2414–23. [12] Hamonic F, Saiter A, Prevosto D, Dargent E, Saiter JM. AIP Conf Proc 2012;1459:211. [13] Saiter A, Couderc H, Grenet J. J Therm Anal Calorim 2007;88(2):483. [14] Bergman R, Swenson J, Borjesson L, Jacobsson P. J Chem Phys 2000;113 (1):357–63. [15] Couderc H, Saiter A, Grenet J, Saiter JM. Physica B 2011;406(14):2908–13. [16] Saiter A, Prevosto D, Passaglia E, Couderc H, Delbreilh L, Saiter JM. Phys Rev E: Stat Nonlinear Soft Matter Phys 2013;88:7. [17] Nguyen HK, Labardi M, Lucchesi M, Rolla P, Prevosto D. Macromolecules 2013;46(2):555–61. [18] Zhang C, Guo YL, Priestley RD. J Polym Sci, Part B: Polym Phys 2013;51 (7):574–86. [19] Arabeche K, Delbreilh L, Adhikari R, Michler GH, Hiltner A, Baer E, et al. Polymer 2102; 53: 1355-1361. [20] Arabeche K, Delbreilh L, Saiter JM, Michler GH, Adhikari R, Baer E. Polymer 2014. http://dx.doi.org/10.1016/j.polymer.2014.02.006. [21] Wu J, Huang G, Qu L, Zheng J. J Non-Cryst Solids 2009;355:1755–9. [22] Capsal JF, Pousserot C, Dantras E, Dandurand J, Lacabanne C. Polymer 2010;51:5207–11. [23] Delpouve N, Lixon C, Saiter A, Dargent E, Grenet J. J Therm Anal Calorim 2009;97(2):541–6. [24] Lixon C, Delpouve N, Saiter A, Dargent E, Grohens Y. Eur Polym J 2008;44 (11):3377–84. [25] Delpouve N, Stoclet G, Saiter A, Dargent E, Marais S. J Phys Chem B 2012;116:4615. [26] Chaaria F, Chaouchea M, Doucet J. Polymer 2003;44:473. [27] Dargent E, Bureau E, Delbreilh L, Zumailan A, Saiter JM. Polymer 2005;46:3090. [28] Saiter A, Dargent E, Saiter JM, Grenet J. J Non-Cryst Solids 2008;354:345–9. [29] Couderc H, Saiter A, Grenet J, Saiter JM, Boiteux G, Nikaj E, et al. Polym Eng Sci 2009;49:836–43. [30] Kattan M, Dargent E, Ledru J, Grenet J. J Appl Polym Sci 2001;81:3405–12. [31] Hamonic F PhD thesis. University of Rouen, France; 2012. [32] Hamonic F, Miri V, Saiter A, Dargent E. Eur Polym J 2014 (accepted).