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ELECTRICAL PROPERTIES AND ELECTRICAL PROPERTIES AND STRUCTURE OF POLYMER COMPOSITES STRUCTURE OF POLYMER COMPOSITES
WITH CONDUCTIVE FILLERSWITH CONDUCTIVE FILLERS2. Filled polymer blends: influence of 2. Filled polymer blends: influence of morphology on spatial distribution morphology on spatial distribution
of filler and electrical propertiesof filler and electrical properties
Ye. P. MamunyaInstitute of Macromolecular Chemistry
National Academy of Sciences of Ukraine Kiev, Ukraine
yemamun@i.kiev.ua
• Immiscible polymer blends create the two-phase systems with variety of morphologies, for example:a) dispersed structure (TPU/PP=80/20)
b) matrix-fiber structure (SAN/PA=70/30)
c) lamellar structure (PP/EPDM=80/20)
d) co-continuous structure (PS/PE=75/25)
• Type of structure mainly depends on the fraction ratio of components, processing (technological regimes) and viscosity ratio.
Types of the polymer blend structureTypes of the polymer blend structure
P. Potschke, D. R. Paul. J. Macromol. Sci., Part C-Polym. Revs., 2003, C43, 87-141.
2
D.A. Zumbrunnen. S. Inamdar. Chem. Eng. Sci., 2001, 56, 3893–3897.
• Schematic description of theblend morphology develop-ment along the axis of a twin-screw extruder for a polymerpair AB.
• Conditions: 1) φB > φA, ηA > ηB
2) φB < φA, ηA < ηB
Forming of the blend structure during processingForming of the blend structure during processing
3
P. Potschke, D. R. Paul. J. Macromol. Sci., Part C-Polym. Revs., 2003, C43, 87-141.
J.K.Lee, C.D.Han. Polymer, 2000, 41, 1799–1815.
J.K.Lee, C.D.Han. Polymer, 1999, 40, 6277–6296.
Structural model of development of the blend Structural model of development of the blend morphology depending on the componets ratio morphology depending on the componets ratio
4
• Depeding on fraction ratio A/B of components the morphology of polymer blend changes from the insulated inclusions of polymer B within polymer A (at low content of polymer B) to the co-continuous structure at equal content of the phases and further to the inclusions of polymer A within polymer B (at low content of polymer A).
A
B
A
B
B
A
B
A
B
A
A B
Polymer A / Polymer B = 100 / 0
Polymer A / Polymer B = 99 / 1
Polymer A / Polymer B = 95 / 5
Polymer A / Polymer B = 50 / 50
Polymer A / Polymer B = 20 / 80
Polymer A / Polymer B = 0 / 100
Polymer blend based on:• Polymer A:cellulose acetate butyrate• Polymer B:polyoxymethylene
There are three regions of mechanical properties of this polymer blend that strongly depend on the structure: (1) corresponds to inclusions of B in A; (2) the polymer components behave as the connected phases; (3) corresponds to inclusions of A in B.
Morphology of polymer blend and derived Morphology of polymer blend and derived mechanical propertiesmechanical properties
Ye. P. Mamunya, E. V. Lebedev, E. N. Brukhnov, Yu. S. Lipatov.Vysokomolek. Soed., 1979, A21, 1008-1013 (in Russian).
5
ε, %σi, kg cm/cm2
σt, σy, kg/cm2
Content of polymer B
A
B
a
A
B
A/B
b
• Thickness of the interfacial layer δs is 2-10 nm and comparable with length of molecular segment.
• Thickness of the transition layer δt is up to 1 μm and defined by conditions of the structure forming.
Yu.S. Lipatov. Physical chemistry of filled polymers.Moscow: Chemistry, 1977 (in Russian).
a bδs δt
a b
δs δt
δs δt
a) TmA<Tproc<TmB
b) TmA<Tproc>TmB
Polymer blend PE-POM = A-B
Temperature of processing
Interfacial region in polymer blendsInterfacial region in polymer blends
Yu.S. Lipatov, Ye. P. Mamunya, E. V. Lebedev, N.A. Sytenko, G.Ya. Boyarskii. Vysokomolek. Soed., 1981, B23, 282-287 (in Russian).
6
Filling of polymers and polymer blendsFilling of polymers and polymer blends
Usually the polymers can be filled for several reasons:• To reduce the cost of polymer product. The cheap and widespread fillers are used;
• To improve the mechanical characteristics (toughness, bendingstrength etc.) of polymer. The reinforcing fillers are used.
• To obtain the colored polymer product. The pigments are used.
• To create the composite material. Content of filler in a polymer is very high (close to the limit of filling). The fiber fillers are often used.
• To impart new properties to the polymer. The functional fillers are used, for example conductive filler (carbon black, dispersed metals) that transforms filled polymer from insulating to conductive state.
• Filing of polymer blend with functional filler suggests additional potential in properties of the functional polymer systems because of heterogeneous structure of the polymer matrix that changes the spatial distribution of the filler. It is very important for conductive polymer systems.
7
• Heterogeneity of polymer blend can influence on spatial distribution of filler in the polymer matrix
• Immiscible polymer blend is two-phase system with developed interfacial region
• Generally 4 cases of spatial distribution of the filler can be realized in the polymer blend:
Influence of heterogeneity of polymer blend on the Influence of heterogeneity of polymer blend on the spatial distribution of filler spatial distribution of filler
8
Filler occupates both of polymer phases
Filler occupates one of twopolymer phases
Filler is localized on the interface
Filler occupates second oftwo polymer phases
filling
• Last three cases of filler distribution are of the highest interests because of nonuniform distribution of filler.
9
Generally 5 methods of filling of the polymer blend exist:
Electrical properties of composites depend on the conductive filler distribution and consequently on the method of filling
Influence of processing on the spatial Influence of processing on the spatial distribution of filler distribution of filler
Filler occupates both of polymer phases
Filler occupates one of twopolymer phases
Filler is localized on the interface
Filler occupates second oftwo polymer phases
filler → polymer 1polymer 2 FPB
polymer 1filler → polymer 2 FPB
filler → polymer 1filler → polymer 2 FPB
polymer 1+
polymer 2 FPBfiller +
polymer 1polymer 2 filler → FPB
1
2
3
4
5
Methods 1- 4 are two-stages, method 5 is one-stage.
polymer 1 polymer 2
processing
filler
filledpolymer blend
10
Variation of the composite composition leads to phase inversion in such a way:
Nonconductive matrix with inclusions of conductive phase
Co-continuous structures of conductive and non-conductive phases
Conductive matrix with inclusions of nonconductive phase
First, the composite is not conductive
Separated inclusions are merged creating the continuous filled phase which provides the appearance of jump of the conductivity
When conductive phase becomes a matrix, the con-ductivity increases slowly due to the decrease of the nonconductive inclusions
Structure
Conductivity
Correlation structureCorrelation structure--conductivity in filled conductivity in filled polymer blendspolymer blends
conductivenonconductive
Filler volume fraction, ϕ
Con
duct
ivity
, log
σ
ϕc
percolation threshold
Region 1
Region 2
Region 3
11
Structure and conductive properties of filled Structure and conductive properties of filled polymer blendpolymer blend
Conductivity of filled polymer blend is a function of the filler content and reflects its heterogenious structure.
Region 1 – the composite is non-conductive, the polymer blend consists of nonconductive polymer 1 with inclusions of filled conductive polymer 2 phase.
Region 2 – Co-continuous conductive and non-conductive unfilled polymer 1 – filled polymer 2 phases. It is a region of percolation, the conductivity sharply increases at ϕ > ϕc.Region 3 – Structure of composite consists of conductive matrix (filled polymer 2) with inclusions of nonconductive polymer 2 phase. The conductivity slowly increases.
J. Feng, C-M. Chan. Polym. Eng. Sci., 1998, 38, 1649-1657.
Double percolation phenomenaDouble percolation phenomena
The conception of double percolation first was proposed by Sumita in 1992.
M. Sumita, K. Sakata, Y. Hayakawa, S. Asai, K. Miyasaka, M. Tanemura. Colloid. Pol. Sci., 1992, 270, 134-139.
PP
HDPE
PMMA
HDPE
• The system is over percolation threshold and conductivity exists when two conditions are fulfilled:
1 - continuity of conductive filler (network 1) within the polymer phase;
2 - continuity of filled conductive phase (network 2) within the polymer matrix.
network 1
network 2
• If one of two networks is destroyed then the composite becomes nonconductive.
12
13
3 factors define the spatial distribution of filler in the two-componets polymer matrix:
Thermodynamic factor
Relationship between interfacial tensions polymer 1 – filler (γp1f), polymer 2 – filler (γp2f) and polymer 1 – polymer 2 (γpp)
Kinetic factor Relationship between viscosities of polymer 1 (ηp1) and polymer 2 (ηp2)
Processing factor
Methods of the filler introduction into the two-components polymer matrix
The main conditions to realize the irregular spatial The main conditions to realize the irregular spatial distribution of filler in polymer blenddistribution of filler in polymer blend
M. Sumita, K. Sakata, S. Asai, K. Miyasaka, H.Nakagawa.Polym. Bull., 1991, 25, 265-271
Parameters, mJ/m2Components of polymer blend γp γpf γpp
HDPE – CBPP – CBPMMA – CBHDPE – PPHDPE – PMMAPMMA - PP
25.920.228.1
---
13.1-12.217.1-16.712.2-14.6
---
---
1.28.66.8
γCB = 55 mJ/m2
BA
CBBCBA
−
−− −=
γγγω
Wetting coefficient
Influence of surface tension on the morphology of Influence of surface tension on the morphology of filled polymer blendfilled polymer blend
PP
PMMA
PP
HDPE
PMMA
HDPE
γA-CB, γB-CB – interfacial tensionpolymer-filler
γA-B – interfacial tension polymer-polymer
Conditions of filler ditribution
ω > 1 CB is distributed within B phase-1 < ω < 1 CB is distributed at the interface
ω < -1 CB is distributed within A phase
14
15
Behaviour of the filler particle on the boundary between components in polymer blend
c
0,0 0,1 0,2 0,3-16
-12
-8
-4
0
lg (σ
, См
/м)
ПП/ПЭ-сажаметод А
2 1
концентратПЭ-сажа
концентратПП-сажа
4 3
0,0 0,1 0,2 0,3
ПП/ПЭ-сажаметод Б
0,0 0,1 0,2 0,3
ПЭ/ПОМ-сажаметод А
6 5
концентратПОМ-сажа
объемная доля наполнителя, ϕ
а б в
PP/PE-CB, ϕc=0.05PE-CB, ϕc=0.09
PE/POM-CB, ϕc=0.03POM-CB, ϕc=0.12
PE/PP-CB, ϕc=0.05PP-CB, ϕc=0.05
log
(σ,
S/m
)
Filler volume fraction, ϕ
Interfacial tensions polymer–filler can be calculated by Fowkes equation or Owens and Wendt equation
( ) ( ) 5,05,0 22 pf
pp
df
dpfppf γγγγγγγ ⋅⋅−⋅⋅−+=
Fowkes eq.
Owens and Wendt eq.
Influence of the thermodynamic factorInfluence of the thermodynamic factor
Ye.P. Mamunya. J. Macromol. Sci.-Phys., 1999, B38, 615-622.
γp1f > γp2f + γpp γp2f > γp1f + γppγp1f < γp2f + γppγp2f < γp1f + γpp
Polymer 1
Polymer 2
Polymer 1
Polymer 2
Polymer 1
Polymer 2
16
• Shift of ϕc and deviation from equation (curves 5 and 5a) are observed in the polymer row PP-PE-PS-PMMA-PA filled with carbon black.• Interaction polymer-filler becomes stronger in the row PP-PA.• The higher difference (γf - γp) or interfacial tension γpf, the more branched conductive structure can be formed. This effect provides low value of percolation threshold ϕc .
log
(σ, S
/m)
Filler volume fraction, ϕ
1 – PP-CB2 – PE-CB 3 – PS-CB 4 – PMMA-CB 5 – PA-CB
Interfacial interaction between polymer and filler Interfacial interaction between polymer and filler
σ= σ0 (ϕ - ϕc)t
Parameters, mJ/m2Components of polymer blend ϕc γp γpf γf- γp
PP – CBPE – CBPS – CBPMMA – CBPA-CB
0.0450.0550.0700.1000.255
30.035.540.743.446.6
3.762.131.070.690.35
25.019.514,311.68.4
γCB = 55 mJ/m2
PP PE
E.P. Mamunya, V.V. Davidenko, E.V. Lebedev. Composite Interfaces, 1997, 4, 169-176.
K. Miyasaka , K. Watanabe, E. Jojima, H. Aida, M. Sumita, K. Ishikawa. J. Mater. Sci., 1982, 17, 1610-1618.
( )nc
cKk
ϕϕ
ϕ
−
⋅=
K = A +B⋅γpf
( ) ( ) 5,05,0 22 pf
pp
df
dpfppf γγγγγγγ ⋅⋅−⋅⋅−+=
Proposed model changes eq. 1 and 2 by eq. 3. Exponent kincludes the value of interfacial tension γpf
Model approach of polymerModel approach of polymer--filler interactionfiller interaction
E.P. Mamunya, V.V. Davidenko, E.V. Lebedev. Composite Interfaces, 1997, 4, 169-176.
1 σ= σ0 (ϕ - ϕc)t
pf
f
VVV
F+
=
Filler packing density coefficient - packing-factor
( )t
c
ccmc F ⎟⎟
⎠
⎞⎜⎜⎝
⎛−−
−+=ϕϕϕ
σσσσ2
( )k
c
ccmc F ⎟⎟
⎠
⎞⎜⎜⎝
⎛−−
⋅−+=ϕϕϕσσσσ loglogloglog3
Wetting of the filler by polymer: 1-poor; 2 – intermediate; 3 - absolute
In the first case the system has low values of ϕc1 and F1. In the last case the percolation appears only at value ϕc3=F3 because the particles are separated by polymer interlayers. PP-CB is closer tothe first case, PA-CB is closer to the last case.
17
M.L. Clingerman, E.H. Weber, J.A. King, K.H. Schulz.J. Appl. Polym. Sci., 2003, 88, 2280-2299.
σp
σc
σm
ϕc F
log σ
Filler content
ϕc1 ϕc3=F3ϕc2 F2F1
log σ
1 2 3
18
• If the polymer components have big difference in the viscosity values (ηp1 >> ηp2) then kinetic factor is essential.
• During processing through polymer melt, under shear stresses, the filler is captured by polymer component with lower viscosity.
0,0 0,1 0,2 0,3 0,4-16
-12
-8
-4
0
4321
Filler volume fraction, ϕ
log
(σ, S
/m)
PE/POM-Fe, ϕc = 0.09PE-Fe, ϕc = 0.21POM-Fe, ϕc = 0.24PA-Fe, ϕc = 0.29
ϕ < ϕc ϕ > ϕc ϕ >> ϕc
POM-Fe
PE
The value of melt flow index(MFI, g/10min) for polymers
PE – 1.6 POM – 10.9 PA – 11.7
The model and the real structure for the filled polymer blend PE/POM-Fe
Influence of the kinetic factorInfluence of the kinetic factor
Ye.P. Mamunya, Yu.V. Muzychenko, P.Pissis, E.V. Lebedev, M.I. Shut. Polym. Eng. Sci., 2002, 42, 90-100.
Conductivity jumps up when the co-continuous structure of polymer phases is appears. There is a region of phase inversion. Existence of such structure in filled polymer blend is necessary to obtain the conductive system.
P. Pötschke, D.R. Paul. J. Macromol. Sci.-Part C., 2003, C43, 87-141.
Φ1=φ1/(φ1+φ2) – continuity index
Definition 1:Co-continuity means the coexistence of two continuous structures within the same volume; both components have three-dimensional spatial continuity.Definition 2:Co-continuous structures are those in which at least a part of each phase forms a coherentcontinuous structure that permeates the whole volume.
19Phase inversion in polymer blendsPhase inversion in polymer blends
• The degree of co-continuity (or continuity index) Φ of a specific phase is the ratio between the extracted mass of this phase and the total content, assuming self-supporting of residuary material after extraction.
C. Lagreve, J.F. Feller, I.Linossier, G. Levesque. Pol. Eng. Sci., 2001, 41, 1124-1132.
P. Pötschke, D.R. Paul. J. Macromol. Sci.-Part C., 2003, C43, 87-141.
F. Gubbels, S. Blacher, E. Vanlathem, R. Jerome, R. Deltour, F.Brouers, Ph. Teyssie. Macromolecules, 1995, 28, 1559-1566.
• Extraction experiments are easy and convenient way to check for co-continuity when the components are soluble in the specific solvents.
Definition of coDefinition of co--continuous phases by extractioncontinuous phases by extraction20
PSPE-CB
PSPE
PS/PE-CB
PBT/(PE-co-AA)-CB(PE-co-AA)-CB phase is extracted
PA6/ABSPA6 phase is extracted
• A co-continuous structure is present if the part remaining after dissolution of the other component is selfsupporting and if its mass is approximately that in the original blend.
Method of selective extraction
P. Pötchke, A.R. Bhattacharyya, A. Janke. Polymer 2003, 44, 8061-8069
Phase inversion in PE/PCPhase inversion in PE/PC--CNT polymer blendCNT polymer blend21
Ratio PE/PC-CNT
80/20 60/40
40/60 20/80
Morphology of PE/PC-CNT composite after extraction of PC-CNT phase by chloroform.
Polymer blend
Intervals of phase
inversion(content of
filled phase)
Type of conductive
filler
Localization of filler Refs.
PMMA/PP 20-60 CB, 10 % PMMA+interf. [1]
PS/SIS 70-80 CB, 2 % PS [2]
CPA/PP 50-70 CB, 2 % CPA [3]
PE/PS 10-60 CB, 4 % PE+interface [4]
LDPE/EVA 50-80 CB, 18 % LDPE+interf. [5]
PC/HDPE 30-80 MWCNT, 2 % PC [6]
POM/PE 30-50 Fe, 32 % POM
CPA/PP 10-20 Fe, 35 % CPAour
study
1. M. Sumita, K. Sakata, Y. Hayakawa, S. Asai, K. Miyasaka, M. Tanemura.Colloid Polym. Sci., 1992, 270, 134-139.
2. R. Tchoudakov, O. Breuer, M. Narkis. Polym. Eng. Sci., 1996, 36, 1336-1346.
3. R. Tchoudakov, O. Breuer, M. Narkis. Polym. Eng. Sci., 1997, 37, 1928-1935.
4. F. Gubbeles, S. Blancher, E. Vanlathem, R. Jerome, R. Deltour, F. Brouers, Ph.Teyssie. Macromolecules, 1995, 28, 1559-1566,.
5. G. Yu, M.Q. Zhang, H.M. Zeng, Y.H. Hou, H.B. Zhang. Polym. Eng. Sci., 1999, 39, 1678-1688.
6. P. Potschke, A.R. Bhattacharyya, A. Janke. Polymer, 2003, 44, 8061-8069.
22
Regions of phase inversion in different polymer blendsRegions of phase inversion in different polymer blends
• Depending on kind of the polymer components the intervals of phase inversion are different.
• Filler can be localized in one of two polymer phases or on the interface.
Localization of filler is defined by both thermodynamic and kinetic factors. Conditions of phase inversion are defined by kinetic factor.
Conditions of phase inversion in polymer blendsConditions of phase inversion in polymer blends
B
A
B
A
ϕϕ
ηη
>
B
A
B
A
ϕϕ
ηη
<
CB
A
B
A ±=ϕϕ
ηη
Phase of B is continuous
Phase of A is continuous
Region of phase inversionC is width of phase inversion region
D.R. Paul, J.W. Barlow. J. Macromol. Sci.-Rev. Macrom. Chem., 1980, C18, 109-168.
Co-contin
uous phas
esContinuous phase of B
Continuous phase of A
1
1
Visc
osity
ratio
A/B
Volume ratio A/B
-2,0
-1,0
0,0
1,0
2,0
0 0,25 0,5 0,75 1
100
10
1
0.1
0.010/1 0.5/0.5 1/0
Volume fraction ratio, ϕ2/ϕ1
Visc
osity
ratio
, η1/η
2
Continuous phase 2
Continuous phase 1
1
2
2
1
ϕϕ
ηη
⋅≥ 1 phase 2 continuous
≤ 1 phase 1 continuous
≈ 1 dual phase continuous
G.M. Jordhamo, J.A. Manson, L.H. Sperling. Polym. Eng. Sci., 1986, 26, 517-524.
23
24
PE/POMPE/POM--FeFe
7Fe 12Fe 18Fe 23Fe 28Fe4Fe 70 μm
5Fe 7Fe 10Fe 15Fe 30Fe3Fe
PP/CPAPP/CPA--FeFe
Nonconductive phase is a matrix.Conductive phase is in a form of separated inclusions
Region 1 Region 2
Region of phase inversion.Conductive and non-conductive phase are co-continuous.
Conductive phase is a matrix.Nonconductive phase is in a form of separa-ted inclusions.
Region 3
PE POM-Fe
PP CPA-Fe
Morphology development of filled polymer blends Morphology development of filled polymer blends
•Such a structure is a result of two stage processing and a big difference of the viscosity of polymer components. The filler is introduced in the low viscous polymer at the first stage and remains in it during second stage of processing.
• Several kinds of phase structure can be formed in the composite:
25
PE/POMPE/POM--FeFePP/CPAPP/CPA--FeFe
Conductive phase is distributed in the form of separated inclusions. Nonconductive phase is a matrix.
PE/POMPE/POM--FeFeConductive and non-conductive phases create the co-conti-nuous structure.
The composite is conductive with conductivity σ1.
PP/CPAPP/CPA--FeFeConductive phase is more branched.The composite is
conductive with conductivity σ2 > σ1 at lower content of filler than in previous case.
PE/POMPE/POM--FeFePP/CPAPP/CPA--FeFe
Conductive phase is a matrix, nonconduc-tivephase is in the form of separated inclusions.
Structure model of conductive phaseStructure model of conductive phase
Relationship of viscosities for the systems:MFIPP/MFICPA = 4.2·10-2
MFIPE/MFIPOM = 1.5·10-1
26
• Composites demonstrate two-step percolation behavior with plateau in the region of phase inversion which corresponds to the co-continuous structure of phases.
• For PE/POMPE/POM--FeFe the plateau located in the interval 12-18 vol.% of FeFe.
• For PP/CPAPP/CPA--FeFe the plateau located in the interval 6-10 vol.% of FeFe.
• It is possible to calculate theore-tical curves separately for region 2 and region 3 (dotted curves in Fig.) with the values of parameters:
σc
ϕc F
σm t
c
c
cm
c
F ⎟⎟⎠
⎞⎜⎜⎝
⎛−−
=−−
ϕϕϕ
σσσσ
parameters of equationσc , σm , ϕc , F
PP/CPAPP/CPA--FeFe
PE/POMPE/POM--FeFeParameters t ϕc,% F, % log σc log σm
PE/POMPE/POM--FeFeregion 2region 2region 3region 3PP/CPAPP/CPA--FeFeregion 2region 2region 3 region 3
3.22.1
1.713
55
99
3535
1232
-15.5-15.5
-15.0-15.0
-2.48-2.32
-7.58-2.51Filler content, ϕ, %
-1
-1
-1
7
4
1
-8
-5
-2
0 0,1 0,2 0,3 0,4
Con
duct
ivity
, log
(σ, S
/cm
)
0 10 20 30 40
PE/POMPE/POM--FeFePP/CPAPP/CPA--FeFe
Conductivity of PP/CPAConductivity of PP/CPA--Fe and PE/POMFe and PE/POM--Fe compositesFe composites
27
PP/CPAPP/CPA--FeFe PE/POMPE/POM--FeFe
• Structure in the region of phase inversion
• Region of phase inversion
• Percolation threshold
• Conductivity on a level of plateau
• Maximal conductivity σmat ϕ = F (conductivity of a master batch)
more branched less branched
plateau 7-10 vol.% plateau 12-18 vol.%
lower (5 vol.%) higher (9 vol.%)
higher (8·10-7 S/cm) lower (6·10-8 S/cm)
equal (3·10-3 S/cm) equal (3·10-3 S/cm)
Features of phase structure and conductivities of Features of phase structure and conductivities of PP/CPAPP/CPA--Fe and PE/POMFe and PE/POM--Fe compositesFe composites
28
Temperature, 0C
Expa
nsio
n / D
efor
mat
ion,
L, %
-1
0
1
2
3
0 40 80 120 160 200
100ПЭ78PE/15POM-7Fe62PE/26POM-12Fe53PE/32POM-15Fe28PE/49POM-23Fe68POM-32Fe100POM
Tm POMTm PE
Expa
nsio
n / D
efor
mat
ion,
L, %
-1
1
3
5
0 40 80 120 160 200
100PP80PP/13CPA-7Fe71PP/19CPA-10Fe57PP/28CPA-15Fe20PP/52CPA-28Fe65CPA-35Fe100CPA
Temperature, 0C
Tm PP
Tm CPA
• In the region of phase inversion the systems PP/CPAPP/CPA--FeFe andand PE/POMPE/POM--FeFehave two peaks of Tm which correspond to the melting point of each polymer phase.
• The slope of TMA curves depends on the composite composition for the system PE/POMPE/POM--FeFe whereas for the system PP/CPAPP/CPA--Fe Fe slope is equal for all compositions.
Thermomechanical analysis (TMA) of PP/CPAThermomechanical analysis (TMA) of PP/CPA--Fe Fe and PE/POMand PE/POM--Fe composites Fe composites
29
0
1
2
3
4
0 10 20 30 40Filler content, ϕ, %
α⋅1
04, 0
C-1
PE/POMPE/POM--FeFePP/CPAPP/CPA--FeFe
PE/POMPE/POM--Fe Fe systemsystem• Coefficient of thermal expansion αundergoes a jump in the region of phase inversion 12-18 % of Fe.• In the region 1 the values of α equal to the α of PE (αPE = 3.10·10-4 0C-1).•In the region 3 the values of α equal to the α of POM-Fe (αPOM-Fe =1.08·10-4 0C-1).
PE/POMPE/POM--Fe Fe systemsystem• The change of the composite composition does not influence on the value of α.•It is a result of equality of the α for polymer phases (PP and CPA-Fe): αPP = 1.80·10-4 0C-1,αCPA-Fe = 1.78·10-4 0C-1.
0LTL⋅
=ΔΔα
Coefficient of thermal Coefficient of thermal expansionexpansion
ΔL/ΔT is a slope of TMA curve; L0 is the initial size of sample.
Thermal expansion of PP/CPAThermal expansion of PP/CPA--Fe and PE/POMFe and PE/POM--Fe Fe composites composites
30
•The regions of phase inversion are different:
- for PP/CPAPP/CPA--FeFe system the region of phase inversion is less extended and shifted to low content of CPACPA;
- for PE/POMPE/POM--FeFe system this region is wider and located at comparable content of polymer phases PEPE and POMPOM.
0
10
20
30
40
0 20 40 60 80 100
Content of CPA (POM) in polymer matrix, vol.%
Con
tent
of F
e in
com
posi
te, v
ol.%
PP/CPAPP/CPA--FeFe
PE/POMPE/POM--FeFe
region of phase inversion
Region of phase inversion:
2929--50 POM50 POM in the polymer matrix1212--20 CPA20 CPA in the polymer matrix
• Relationship between content of filler in the polymer blend and the composition of polymer matrix.
Regions of phase inversion in PP/CPARegions of phase inversion in PP/CPA--Fe and Fe and PE/POMPE/POM--Fe composites Fe composites
0 0.25 0.5 0.75 1
η EPR
/ηPP
(200
0 C, γ
= 5.
5 s-1
)
MFI
PP (P
E)/M
FIC
PA(P
OM
)(1
90 0 C
, P=2
.16
kg)
101
100
10-1
Weight fraction of PP
Continuous EPR phase
Continuous PP phase
Co-continuous phase
PE/POMPE/POM--FeFe
PP/CPAPP/CPA--FeFe
31
D. Romanini, E. Garagnani, E. Marchetti. In: Martuscelli E., Marchetta C., editors. New polymeric materials. Reactive processing and physical properties. Utrecht: VNU Science Press, 1987, p. 56-87.
• Intervals of phase inversion of composites PE/POMPE/POM--FeFe and PP/CPAPP/CPA--FeFe were superimposed on the plot for EPR/PP system.
• In spite of using the ratio of MFIsinstead of ratio of viscosities the intervals of phase inversions for the EPR/PP system and for the PE/POMPE/POM--FeFe and PP/CPAPP/CPA--FeFecomposites are in good agreement.
Ratio of viscosities for PE/POMPE/POM--FeFe and PP/CPAPP/CPA--FeFecomposites:
MFIPP/MFICPA = 4.2·10-2
MFIPE/MFIPOM = 1.5·10-1
Influence of rheology on phase inversion in Influence of rheology on phase inversion in polymer blendspolymer blends
Influence of Influence of rheologyrheology on phase inversions in on phase inversions in polymer blendspolymer blends
32
- the higher is difference between viscosities of polymer phases, the narrower is the region of phase inversion and more shifted to the smaller content of low viscous polymer phase.
MFI
PP (P
E)/M
FIC
PA(P
OM
)(1
90 0 C
, P=2
.16
kg)
0 0.25 0.5 0.75 1
η EPR
/ηPP
(200
0 C, γ
= 5.
5 s-1
)
101
100
10-1
Weight fraction of PP
Continuous EPR phase
Continuous PP phase
Co-continuous phases
Continuous POM-Fe phase
Continuous PE phase
PE/POMPE/POM--FeFe
Continuous CPA-Fe phase
Continuous PP phasePP/CPAPP/CPA--FeFe
11
2
2
1 ≈×ϕϕ
ηη
• The rule for the point of phase inversion was calculated as well :
• These data (on the example of PE/POMPE/POM--Fe Fe andand PP/CPAPP/CPA--Fe Fe composites) composites) display the peculiarities of phase behavior:
D. Romanini, E. Garagnani, E. Marchetti. In: Martuscelli E., Marchetta C., editors. New polymeric materials. Reactive processing and physical properties. Utrecht: VNU Science Press, 1987, p. 56-87.
G.M. Jordhamo, J.A. Manson, L.H. Sperling. Polym. Eng. Sci., 1986, 26, 517-524.
EVOH - copoly(ethylene-vinyl-alcohol) with 32 and 38 mole percent ethylenePolymer blend EVOH / CoPA-6/6.9
Polymer blends for the food packaging materialsPolymer blends for the food packaging materials
• The value of permeability relatively to different gases: oxygen, carbon dioxide, water vapor are very important for the food packaging materials.
• Using of polymer blends allows to regulate the diffusion properties of film material.
• Rate of gas diffusion depends on phase morphology of polymer blend.
Y. Nir, M. Narkis, A. Siegmann. Polym. Networks Blends, 1997, 7, 139-146.
33
Materials:
Filler content
log
Res
istiv
ity
ϕc
log
Res
istiv
ity
Ts Temperature
PTC effect in conductive polymer systemsPTC effect in conductive polymer systems
• During heating the deconnexion of the percolating network occurs due to the matrix thermal expansion. This effect is reversible.
• Filled polymer is converted from conductive to nonconductive state.
• Ts – sweaching temperature for conductive/nonconductive states.
34
G. Boiteux, Ye.P. Mamunya, E.V. Lebedev, C. Boullanger, A.Adamczewski,P. Cassagnau, G. Seytre. Synthetic Metals, 2007, 157(24), 1071-1073.
thermistances
H.M. Zeng, Y.H. Hou, H.B. Zhang. Polym. Eng. Sci., 1999, 39, 1678-1688. (Scheme),
Z. Zhao, W. Yu, X. He, X. Chen. Mater. Lett., 2003, 57, 3082-3088.
35
PTC effect in filled polymers and polymer blendsPTC effect in filled polymers and polymer blends
(PVDF-CB)
Parameters of PTC dependence
Use the polymer blend as the polymer matrix instead of the individual polymer eliminates NTC effect.
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