VLTX305(1).pdf

Vlákna a Textil (3) 2005

Fibres and Textiles (3) 2005

CONTENTS

FIBRE-FORMING POLYMERS

98 Marcinčin A., Hricová M., Fedorko P., Olejniková K.

Fibre forming electrically conductive polymer composites

104 Krištofič M., Náčiniaková Z., Legéň J., Ryba J.

Polypropylene fibres modified by copolyamides

Part I. Preparation of modifiers, modofied fibres and their

properties

111 Bolhová E.,Ujhelyiová A., Strecká Z.,Rusnák A.,Legéň J.

The influence of polyvinyl alcohol and nanoadditive on the

colouristic properties of modified polypropylene fibres

TESTING METHODS

116 Prousek, J., Vavreková L.

Coagulant pretreatment and Fenton treatment of coloured

wastewotwrs from cotton dyeing containing one or mixture of

CIBACROM bifunctional reactive dyes: Yellow FN-2R, Red

FN3G, and Navy FN-B

REVIEW ARTICLES

121 Marcinčin A., Dolgoš O.

Polymer (fibre forming) nanocoposites, preparation, structure

and properties

128 Mazíková V., Sroková I.

Polymer tenside from revivable stuff

133 Balogová Ľ., Šesták J.

Solar ultraviolet radiation and textiles providing protection

against its adverse effects

NEWS FROM DEPARTMENTS

138 Pollák M.

Harmful chemical comounds in textiles

142 Abstracts of students thesis defended at Department of textile

and clothing, FIT TnU Alexander Dubček in Púchov after 5

year’s graduate study in 2004/200 5

OBSAH

VLÁKNOTVORNÉ POLYMÉRY

98 Marcinčin A., Hricová M., Fedorko P., Olejniková K.

Vláknotvorné elektricky vodivé polymérne kompozity

104 Krištofič M., Náčiniaková Z., Legéň J., Ryba J

Polypropylénové vlákna modifikované kopolyamidmi

Časť I. Príprava modofikátorov, modifikované vlákna a ich

vlastnosti

111 Bolhová E.,Ujhelyiová A., Strecká Z.,Rusnák A.,Legéň J.

Vplyv polyvinylalkoholu a nanoaditíva na koloristické vlastnosti

Modifikovaných polypropylénových vlákien

SKÚŠOBNÉ METÓDY

116 Prousek J., Vavreková L.

Koagulačná predúprava a použitie Fentonovej reakcie na

čistenie farebných odpadových vôd z farbenia bavlny jednou

alebo zmesou CIBACRON bifunkčných reaktívnych farbív:

Yellow FN-2R, Red FN-3G a Navy FN-B

PREHĽADNÉ ČLÁNKY

121 Marcinčin A., Dolgoš O.

Polymérne (vláknité) nanokompozity, príprava, štruktúra

a vlastnosti

128 Mazíková V., Sroková I.

Polymérne tenzidy z obnoviteľných surovín

133 Balogová Ľ., Šesták J.

Slnečné UV žiarenie a ochrana textíliami pred jeho negatívnym

vplyvmi

Z VEDECKO-VÝSKUMNÝCH A VÝVOJOVÝCH PRA-

COVÍSK

138 Pollák M.

Škodlivé chemické látky v textíliách

142 Súhrny diplomových prác na Katedre textilu a odievania, FPT

TnU A. D. so sídlom v Púchove v rámci inžinierskeho štúdia

v školskom roku 2004/2005

Vlákna a textil 12 (3) 97 (2005)

Vláknotvorné polyméry

Fibre-Forming Polymers

Fibre-forming electrically conductive polymer composites

Marcinčin A., Hricová, M., Fedorko P., Olejníková K.

Slovak University of Technology in Bratislava, Faculty of Chemical and Food Technology,

Radlinského 9, 812 37 Bratislava, Slovakia, e-mail: anton.marcincin @ stuba.sk

The paper deals with the preparation conditions, rheological properties and electrical conduc-

tivity of fiber-forming polymer composites based on the poly(ethylene terephthalate) (PET) and

conductive carbon black pigment (Printex L6). Polymer composites were prepared in wide scale of

the pigment concentration (0-30 wt%) by original method for PET pigment concentrates for spun

dyed fibres. Capillary extrusiometer was used for the measurement of rheological properties. Direct

current electrical conductivity of the PET composites was measured by the standard four-contact

method at room temperature and the percolation threshold (critical concentration of pigment) was

evaluated. Correlations between rheological and electrical properties as well as effect of the se-

lected additives of composites on electrical conductivity are discussed. The PET composite fibres

were prepared by melt spinning up to 6 wt% of carbon black pigment. Electrical conductivity only

on the antistatic level was obtained.

1. Introduction

ment decreases to one half of the non-filled one. Poly-

propylene/carbon black (30 wt%) composites exhibit

two times higher Young modulus and about 25% de-

crease in the tensile strength. The elongation at break

decreases several times and the electrical conductivity

increases from 10 –10 S.cm –1 (for unmodified PP) to 1

S.cm –1 . At low concentration above the percolation

threshold, the electrical conductivity of filled polymers

increases rapidly with the concentration of the active

filler. When the full contact of the conductive particles is

achieved (at about 20–30 wt% of the filler), the increase

of the conductivity is significantly lower [2, 5].

Electrically conductive fibres based on common

fibre-forming polymers and conductive fillers appear in

periodic literature rarely. The first percolation threshold

(first critical concentration) corresponding to a sharp

decrease of the electrical resistivity to the antistatic

level has been found for 3 wt% of carbon black dis-

persion in PP and polyethyleneoctene (PoE) fibres

[2]. However, at higher pigment concentration a fibre

break occurred and the mechanical properties were

dramatically worsened. The melt viscosity increased

distinctly and the melt spinning was no longer pos-

sible. An acceptable spinning for PP/POE blends with

higher carbon black concentration (up to 12 wt%) was

obtained but only an antistatic level of conductivity of

the filled fibres was reached in this experiment.

There are several ways how to decrease the filler

concentration in the polymer matrix and to improve the

composite processing without loosing the mechanical

properties and electrical conductivity. The conductivity

of filled polymers can be increased by the deformation

of the polymer (drawn fibres). Thermal treatment of

filled semicrystalline polymers leads also to significantly

higher electrical conductivity [12]. A positive influence

on the conductivity has been found when a combina-

tion of conductive additives (nanofiller and polymer) is

used for modification of polymers [2, 13–16]. Conduc-

Electrically conductive polymer fibrous materials

have attracted much attention in the last decade, mainly

in connection with the development of new fibrous

materials for responsive and smart textiles. Conducting

fibres represent a group of special polymer materials

due to the anisotropy of their structure and mechanical

properties. They can be divided in to several groups

according to their nature: 1. inorganic fibres (metal,

ceramic, carbon); 2. organic fibres (based on organic

conductive polymers – polyacetylene, polyaniline and

polypyrrole, partially carbonised organic fibres); 3.

modified fibres (filled with conductive carbon pigments,

metal powders and conductive compounds); 4. fibres

coated by conducting layers (metal coated, coated

by conductive organic compounds and metal com-

pounds).

Mainly electrically conductive fibres based on com-

mon fibre-forming polymers are interesting for textile

application [1, 2]. From this point of view, the formula-

tion of the fibre-forming conductive composites is very

actual. The electrical conductivity of composites based

on a non-conductive polymer matrix and conductive

dispersed particles depends significantly on the ex-

istence of a continuous conducting path across the

sample (percolation effect). Further, it is determined by

the morphology of the filled polymer [3–5].

Conductive carbon black pigments, short carbon

microfibres and carbon nanotubes are the most often

used as the conductive dispersed phase in polymers

[6–9]. Some of these materials have been commer-

cialised during the last twenty years [10, 11]. The draw-

back of these usually high filled materials (15–40 wt%

of filler needed to obtain the required conductivity) is

their insufficient processing in spinning and a strong

decrease of their mechanical properties. The tenacity

of viscose fibres containing 30 wt% of carbon black pig-

Vlákna a textil 12 (3) 98–103 (2005)

Vláknotvorné polyméry

Fibre-Forming Polymers

tive nanofillers represent very effective additives for

improvement of the composite conductivity. A very

interesting method consists in the control of the phase

structure of nanocomposites based on immiscible

polymer components and conductive nanofillers [17].

In any case, according to literature, there is no simple

way of manufacturing conductive fibres already in the

antistatic range by simply filling PP with carbon black,

because of insufficient spinnability and poor mechani-

cal properties of the fibres [2].

In this paper, the rheological properties and electri-

cal conductivity of poly(ethylene terephthalate) (PET)

and polypropylene (PP) filled with C.I. Pigment Black

7 (carbon black) are presented and the possibility of

their application in spinning of the conductive fibres is

discussed.

Table 1 Composition of the PET(PP)/Printex L6 composites

PET LFK

[%]

PP Tatren

[%]

Printex

L6, [%]

Additives

1 96,5 - 3 0,5% M-350

2 93,5 - 6 0,5% M-350

3 89 - 10 1,0% M-350

4 83,5 - 15 1,5% M-350

5 78,5 - 20 1,5% M-350

6 73,5 - 25 1,5% M-350

7 68,5 - 30 1,5% M-350

8 67,6 30 2,1 0,3% M-350

9 65,5 30 4,2 0,3% M-350

10 62,3 30 7,0 0,7% M-350

11 58,5 30 10,5 1,0% M-350

12 55,0 30 14,0 1,0% M-350

13 51,5 30 17,5 1,0% M-350

14 48,0 30 21,0 1,0% M-350

15 81,3 - 15 0,7% M-350 3% LiE

16 77,3 - 15 0,7% M-350 7% Teg

17 77,3 - 15 0,7% M-350 7% S 44P

18 57,8 23,4 15 0,8% M-350 3% LiE

19 53,8 23,4 15 0,8% M-350 7% Teg

20 53,8 23,4 15 0,8% M-350 7% S 44P

2. Experimental

Materials

Polymer: Polyethylene terephthalate LFK (PET),

(SH Senica a.s.)

Polypropylene Tatren HPF (PP),

(Slovnaft Co.)

Carbon black: Printex L-6, (Degussa Co.)

Additives: Polyester wax Licowax E (LiE),

(Clariant AG)

The pressure in front of the capillary and the extrudate

volume were evaluated for the calculation of the ba-

sic rheological parameters of the polymer composite

melt:

– viscosity η - from the Newton equation τ = η . γ •

– power low index n – from the Ostwald de Waele

power law τ = k. γ • n

– agglomeration coefficient λ – from the straight line

dependence log η = log η ∞ + λ . τ –1

where τ – shear stress (at the capillary wall), γ • – shear

rate, k – coefficient, η ∞ – viscosity of the dispersion at

τ → ∞ .

Electrical conductivity: For the electrical conductivity

measurements, the samples of polymer/carbon black

composites were extruded in form of strings using the

Plastometer at 275 ° C. The strings were cooled in water

and cut to the length approximately 10 cm. Direct cur-

rent electrical conductivity of the PET(PP) composite

strings was measured by the standard four-contact

method at room temperature. Four contacts were paint-

ed on the string with silver paint and gold wires were

pressed against them. Tesla Microvoltmeter-Picoam-

meter BM 545 and Metra Blansko Multimeter M1T

380 were used for the measurements of the electrical

current and voltage, respectively.

The conductivity was obtained from the relation:

Poly(siloxane) additives Tegopren (Teg),

(Degussa Co.)

Polypropylene glycol and stearic acid

ester Slovacid 44P (S44P), (Sasol Co)

Silicone oil M-350, (Bayer Chemicals).

Preparation of the PET(PP)/carbon black composites

The PET (PP) concentrate dispersions (composites)

of the carbon black Printex L6 were prepared using

twin screw extruder Werner Pfleiderer φ = 28 mm at

280 ° C. First, the powders of the polymer and pigment

were mixed in a fluid mixer for 3 min. In the next step,

the powder mixture was melted, kneaded and extruded.

As a result, concentrate dispersions in a chips form,

containing 3–30 wt% of black pigment, were obtained.

Selected concentrates were subsequently mixed with

30 wt% of PP. Compatibilisers, which are used in

preparation of the PET/carbon black pigment concen-

trates for pigmenting of PET fibres in mass, were ap-

plied into the mixture to improve the interaction of the

pigment particles with PET matrix. The composition of

the PET(PP)/carbon black composites is given in the

Table 1.

Methods used

Rheological properties: The capillary rheoviscosim-

eter Göttfert with the extruder φ = 20 mm for the mea-

surement of the rheological properties of the polymer

pigment concentrate dispersions at 275 ° C was used.

σ = ( I / U )×( d / S )

where: σ – conductivity, I – current applied through the

outer contacts, U – voltage between the inner contacts,

Vlákna a textil 12 (3) 98–103 (2005)

Vláknotvorné polyméry

Fibre-Forming Polymers

S – string cross section and d – distance between the

voltage contacts.

Table 3 Electrical conductivity of the PET/carbon black Printex

L6 composites

Printex L6

[%]

Conductivity σ

[S.cm -1 ]

3,6.10 -4

4,6.10 -3

3,7.10 -2

9,7.10 -2

3,2.10 -1

5,8.10 -1

1,0.10 0

Fig. 1 Four-contact method for the electrical conductivity measure-

ments, A – ammeter, V – voltmeter, R – resistor

Table 4 Electrical conductivity of the PET(PP)/carbon black Prin-

tex L6 composites, (content of PP 30 wt%)

Printex L6

[%]

Conductivity σ

[S.cm –1 ]

Results and discussion

2,1

6.10 –6

Rheological properties of the polymer/solid particles

composites depend on the concentration of the filler

and on the size and distribution of the particles in the

polymer matrix. The electrical conductivity of polymers

filled with electrically conductive particles depends in

principle on the same variables. The size of the primary

particles of the carbon black pigment is of the nano-

metric level. In the real composites the particles form

large agglomerates which can create a conductive net

at higher concentration.

4,2

1,4.10 –3

7,0

9.10 –3

10,5

4,5.10 –2

4,3.10 -2

17,5

2,4.10 -1

5,6.10 -1

The dispersion of the pigment Printex L6 in PET

behaves as a non-Newtonian liquid (Fig. 2, Table 2).

The melt viscosity of the dispersion increases with

the concentration of the carbon black pigment in PET

(Fig. 2–4). The dependence of viscosity on the pig-

ment concentration changes approximately at 15 wt%

of carbon black content in PET (Fig. 4). Higher slope

of the curve at higher concentrations of the pigment

indicates a change in the structure of the dispersion.

The agglomerates of the pigment grow the number of

contacts between particles increases and the flow of

the melt composite is reduced. At low concentration

of the pigment, the power law index n decreases with

increasing of pigment concentration, at higher con-

Table 2 Coefficients of the rheological equations (in the chapter

“Methods used”) for the PET(PP)/Printex L6 dispersions

No.

Printex L6

[%]

876

0,75

0,06

907

0,75

0,09

1331

0,70

0,12

2259

0,63

0,17

2955

0,62

0,22

2875

0,69

0,30

2410

0,74

0,18

Fig. 2 Dependence of shear stress τ on shear rate γ • (a) and viscosity η on τ –1 (b) for PET/Printex L6 concentrate dispersions.

Concentration of the pigment in the composites: 1 – 3 wt%, 2 – 6 wt%, 3 – 10 wt%, 4 – 15 wt%, 5 – 20 wt%, 6 – 25 wt%, 7 – 30 wt%

100

Vlákna a textil 12 (3) 98–103 (2005)

Vláknotvorné polyméry

Fibre-Forming Polymers

Fig. 3 (a) Dependence of the viscosity η on the shear rate γ • for PET/Printex L6 concentrate dispersions. Concentration of the pigment in

the composites: 1 – 3 wt%, 2 – 6 wt%, 3 – 10 wt%, 4 – 15 wt%, 5 – 20 wt%, 6 – 25 wt%, 7 – 30 wt%.

(b) Dependence of the power law index n and agglomeration coefficient λ of the PET/Printex L6 concentrate dispersions

(T = 275 ° C) on the content of the carbon black Printex L6

Table 5 Influence of compatibilisers on the electrical conductivity

of PET(PP)/Printex L6 composites

Printex L6

[%]

Compatibiliser

[%]

Conductivity σ

[S.cm –1 ]

–

3% LiE

2,3.10 –2

–

7% Teg

7,3.10 –2

–

7% S 44P

4,3.10 –2

3% LiE

6,4.10 –2

7% Teg

7,1.10 –2

7% S 44P

9,1.10 –2

Fig. 4 Dependence of the viscosity of the PET/Printex L6 concentra-

te dispersions ( γ • = 200 s –1 , T = 275 ° C) on the content of the

carbon black Printex L6

(Table 2, Fig. 3b). The maximum of the deviation from

the Newtonian flow (minimum of n) is obtained for the

same concentration as the “break” of the dependence

of the viscosity on the pigment concentration (Fig. 4).

The “agglomeration coefficient” λ increases with the

carbon black concentration.

The electrical conductivity of the PET/carbon black

composites increases with the pigment concentration

(Fig. 5). A very low percolation threshold (the critical

centration passes thorough a minimum and begins to

increase above 20 wt% concentration of the pigment

Fig. 5 Dependence of the conductivity of PET/Printex L6 (a) and PET(PP)/Printex L6 (b)

Vlákna a textil 12 (3) 98–103 (2005)

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