kompozyty gumowe z odpadową ziemią okrzemkową

kompozyty gumowe z odpadową ziemią okrzemkową

Cedric Gay-Berthet

Mariusz Siciński

Joanna Kleczewska

Rafał Anyszka

Dariusz M. Bieliński

Properties of rubber composites containing diatomite brewery waste

The paper is devoted to the problem of utilization of diatomite brewery waste. Experimental results and discussion concentrate on possibilities and limitations of nzbber composites containing the waste in rela­

tion to morphology of the materials. Mechanical and tribological properties justifies application of diato­

mite brewery was te as a filler in rnbber goods for not demanding, generał applications. The best results have been obtained for the moderate amount of filler, no matter it was dried 01· not prior to the mixing with rnbber. The "cl_rying preparation" of cliatomite was te plays a role only in the case when value of the swface energy of the nzbber composites and its character have to be modified.

Key words: rnbber composites, diatomite brewe1y waste, morphology, properties

Właściwości kompozytów gumowych zawierających pofiltracyjną ziemię okrzemkową pochodzącą z browaru

Artykuł poświęcony jest problemowi zagospodarowania pofiltracyjnej ziemi okrzemkowej pochodzącej z browam. Wyniki badari ekspe1ymentalnych i ich dyskusja koncentrują się wokół moifologii kompozy­

tów gumowych zawierających odpady ziemi okrzemkowej oraz możliwości i ograniczeń ich wykorzysta­

nia. 14'łaściwo.fri mechaniczne i trybologiczne uzyskanych materiałów uzasadniają stosowanie tych odpadów jako napełniacza w niezbyt wymagających wyrobach gumowych ogólnego przeznaczenia, któ­

rym nie stawia się zbyt wygórowanych wymagań. Najlepsze właściwości uzyskano w przypadku kompo­

zytów gumowych napełnionych w umiarkowanych granicach, niezależnie od tego, czy ziemię okrzemko­

wą przed mieszaniem z kauczukiem poddano procesowi suszenia, czy nie. Wcześniejsza „preparacja przez suszenie" pofiltracyjnych odpadów browarniczych odgrywa rolę jedynie w przypadku, kiedy mamy zamiar zmodyfikować wartość energii powierzchniowej kompozytów gumowych lub jej charak- te1:

Słowa kluczowe: kompozyty gumowe, pofiltracyjna ziemia okrzemkowa z browaru, moifologia, właś­

ciwości

3

I. I ntroduction

Industiial chemical wastes have always be a prob­

lem. It is not always possible to degrade or to burn them, either due to their high chemical stability or toxicity of degradation products [1}. Difficult utilization, economi­

cal and ecological considerations, made people tried to reuse some of them as components of new mate1ials for generał application. Polymer composites are good exam­

ple of this trend, because of their common use, easy and cheap processing. There are pl enty of reports to be found in the subject literature on application of textile [21 or rubber wastes [3) in pol_ymer technology.

1 Ecole l'olytcchnic1uc de l'Cnivcrsitć de Tours, Departmcnt of Indus­

trial Engineering, Tours, FRANCE

2 Tcclmical Univcrsity of tódź, Institute of Polymcr & Dye Technology, tódź, POLAND

'.l Institute for Engineering of l'ol}�ncr :Vlatcrials & Dyes, Division of Elastomers and Ruhbcr Technology, Piastów, POU\ND

Comparatively less attention has been devoted to the possibility of recycling wastes coming from food indust:J.y.

It is mainly because they can ve1y often be applied as ferti­

lizers [41, used to feed !ivcstock [5] or se1ved as valuable substrates for civil engineering or biotechnology [6}.

Nevertheless, there arc stili same of them, nobody knows what to do with. The typical example is diatomite brewe1y waste, u sed for filt:J.·ation of beer or winc after fermenta­

tion. Brewedes face the problem how to get 1id of0.5-0.7 kg of the "wet" diatomite waste (dty mass content 7-25%) accompanying production eve1y hl of beer [7}. In the past they ny to interest our fanncrs, oITedng the waste to them as good fertilizer for reasonable p1ice. Unfortunately, the market quickly ve1ified agricultural usefulness of the brewe1y diatomite waste. Despite the mateJial is rich of ycast, bacte1ia and other residues, left after fennentation process, it produces firm silicate layer on the smface of soi! after some time from application. Such a "coating"

makes bulk penet:J.·ation of air, water and other ingredients or factors, important for fertility of soi!, more difficult.

* CmTesponding author: dhiclin@p.lodz.pl

ELASTOMERY nr 6

In this study the attempt has becn made to apply diatomite brewery waste as a filler for rubber. The

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4 ^{kompozyty gumowe} z odpadową ziemią okrzemkową

vulcanizates have been compared, according to their mechanical durability, tribological properties and ageing rcsistancc to typical engineering materials fillcd with inactivc fillcrs.

2. Experimental 2.1. Materials

Sulphur vulcanizates of natura! rubbcr, RSS II (NR), filled with 40 or 80 płu· of diatomite brewery wastc were studicd. Diatomite waste was applied as reccivcd (wet) or dried at 180^°C for 24 hrs prior to USC. Composition of the rubber mixes is given in Table 1.

Table 1. Composition of the r ubber mixes studied (phr) Tabela 1. Skład badanych mieszanek gu mowych (cz. wag./100 cz. wag. kauczuku)

Rubbcr mi-..

Comp_o!��

RSS Il

i--- -·

ZnO Stemic acid -· MWCNT

I

I ^{phr �vet}

'.�:li°

^I

I I��-,

Diatomite wastc "dry'' , -

! -

Diatorrtite waste "wet"+ 40 i 80

I -

Acceleralor M - .

_-

·-1

Sulphur

I

phr80 100dry

I 5

1

I -

80 2 2 After initial plasticization of rubbcr, diatomite waste was added to the mixing chamber of Brabendcr-Plasti­

cordcr micromixer (Ge1many), operating under the fol­

lowing technological regime: rotor speed n = 45 rpm, room tempcrature, time t = 15 min. After cooling down, the cming system, composed of sulphur and accelerator (see Table 1) was added to the premixcs using a David Biidge (UK) laborat01y two-rolls mill.

Rubber samples were vulcanized in the steel mould at 150 ^°C, dming time t0.9, dete1mincd rheomet:iically according to PN-ISO 3417.

2.2. Techniques

Diatomite wastes werc characterized by pH mea­

surcment. Water solutions made of 75 ml ofwater and 1 O g of d1ied diatomitc were mcasured after 24 hrs.

Mechanical propc11ies of rubber compositcs, before and after thermal ageing (70 °C / 72 hrs), were detcr­

mincd with a Zwick 1405 (Germany) mechanical testing machine, according to ISO 37.

Tiibological tests wcrc carried out against stainless steel counterface, with a błock-on-ling T-05 tribometer (ITcE, Poland), opcrating under a sliding speed of 12 cm/s and a norma) load of 21.4 N. The tribomctcr was equippcd with a multi-channel electronic PC measure-

mcnt unit - Spider 8 (HBM, Germany) for data acquisi­

tion. Each measurement was rcalized dming 2 hrs, with a scanning frequency of 1200 Hz. Coefficient of friction was calculated using well known Amontos' fonnula, ap­

plying average force collectcd for the period of stabilized friction. After each test mass loss of the samples was de­

te11nined gravimellically and abrasion by volume of the rubber samples was calculatcd. Density of the vulcani­

zates was dctermined according to ISO 1183, applying method A

Surface energy of the mate1ials was calculated from contact anglc data, determined with a home-made goniometer, equipped with a CCD camera and a Multi­

Scan 8.0 softv.are for picture analysis (CSS, Poland) (8), for distilled water and diiodomethane. Calculations of the surface energy and its components were based on the Owens-Wendt method [9]. which permits to cva­

luate its dispersivc and polar components.

Morphology of the rubber samplcs was studied using a Met:i·ology Series 2000 (Molecular Imaging, USA) ato­

mie force microscope (AFM), equipped with a NSC 11 silicon cantilcver (MicroMash, Estonia) of the resonant frequency of 65 kHz and the force constant of 3 N/m.

The inst:iument operated under the oscillating mode with a height and a phase scale, at a scan frequency of 1 Hz. Images were analyzed using the WSxM freeware (Nanotec, Spain) [10). Complementary scanning elce­

tron microscopy (SEM) analysis of the mate1ials was perfonned using a Hitachi S-2460N instmment (Japan).

Images of the cross-sectioned mate1ials and diatomite wastes werc collected under magnification from 100 up to 10,000x.

3. Results & Discussion

Application of diatomite waste, no matter in "wet" or

"d1y" form, changes significantly paramcters of rubber vulcanization - Table 2. The higher the amount of filler the longcr the time of vulcanization and the scorch time.

Table 2. Vulcanization parameters of the rubber mixes studied

Tabela 2. Parametry wulkanizacji badanych mieszanek gumowych

�

40 phr 80 phr 40 phr 80 phr

p wet wet dry dry

Scorch time, ,0.2 (s) 60 149 72 140

Time of vulcani-

I

�

5.0 12.8 zation, to.9 (min)

-

Minimum torquc,Mm,n.(dNm) 4.7 14.7 5.7 10.7

-

I

Maximum torquc, 74.7 91.7 86.7 93.7

Mrnax.(dNm)

Increasc of torquc, 70 77 81 83

t.M (dNm)

i

Temperaturc of ,ulcanization: 150 °C

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kompozyty gumowe z odpadową ziemią okrzemkową 5

A TS (MPa) before and after ageing

16 14 12

-

o

Row 16 El Row 31

80 phr Dry

B Eb (%} before and after ageing

g

700 600 500 400 300 200 100

o

berore ageing 13 arter ageing

40 phr Wet 80 phr Wet 40 phr Dry 80 phr Dry

Figure 1. Influence of /wat ageing ⁰¹¹ mechanical properties of the rubber composites filled with diatomite waste.

A) tensile strength, TS; B) elongation at break, E_b

Rysunek 1. Wpływ starzenia cieplnego na właściwości mechaniczne kompozytów gumowych zawierających ziemię okrzemkową. Jl) wytrzymałość na rozciąganie, TS; B) wydłużenie przy zerwaniu, E_1,

Mechanical propcrties of the rubber composites studied, bcfore and aftcr the1mal agcing arc presentcd in Figurc 1. Values bcfore agcing arc similar to the values for typical engineering matc1ials fillcd with inactivc fillers.

Despitc encouraging rcsults on the resistancc of rub­

bcr compositcs containing diatomite brewe1y wastc to heat agcing, p1ior to the finał dccision on their applica­

tion, the materials should be tested for thcir biodcgra­

dation. Generally as cxpected, mechanical prope1tics deteriorate with increasc of filler loading. Therc is not a big difference between the compositcs containing

"wet" or "d1y" diatomitc waste.

The results of tribological tests arc prcsented in Fi­

gure 2.

Again, therc is practically no differcncc conccrning the coefficicnt of friction between compositcs fillcd with

"wet" or "d1y" diatomite wastc. But the coefficicnt of f^riction dccreascs by about 15% with the increase of filler con tent. Dcspite the moderatc differcnce in fiiction the composites exhibit quite a big difference according to abrasion resistancc -Figure 3.

Thcre is a big diffcrence betwecn abrasion resistance of the composites filled with "wet" or "d_1y" diatomite waste. lncrease of"d1y" filler loading improves abrasion resistancc of the rubber composite, whereas in the case of "wet" diatomite waste it makes the abrasion of mate­

riał increased significantl_y.

Explanation on the phenomenon has to be lookcd for analyzing morphology of the materials - Figures 4 and 5.

D1ying of diatomite waste results in the decrease of filler paiticle si.ze. lt looks likc big fragments of shells or skeletons left after fo1mer sca creatures have been bro­

ken into pieccs of sharper edges. Howevcr, virgin diato-

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6 ^{kompozyty gumowe} z odpadową ziemią okrzemkową

0,9

0,85

.., g ^0,8

·.:;

QJ o u

.ę

u. ·;:

0,7

0,65

40 phr Wet 80 phr Wet 40 phr Dry 80 phr Dry

Figure 2. Coefficient of friction for the rubber composites filled with diatomite waste Rysunek 2. Współczynnik tarcia kompozytów gumowych napełnionych ziemią okrzemkową

1,6 Abrasion

1,4 M 1,2

� E

"'

E :, 0,8

o _>

o

...J o 0,4

,-

0,2

-·

o I I

40 phrWet 80 phr Wet 40 phr Dry 80 phr Dry

Figure 3. Abrasion of the rubber composites filled with diatomite waste

Rysunek 3. Zużycie ścierne kompozytów gumowych napełnionych ziemią okrzemkową

mite particlcs prcserve thcir charactcr aftcr mixing. Rub­

ber composites with addition of"wet" waste stili contain big and rounded filler pa1ticles, contra_ry to the "d_ry"

filler, producing more fine morphology: Dispersion of filler pa1ticles in rubber is uniform, no matter the kind of diatomite waste has been applied. Admixing 80 phr of filler results in high filler agglomeration, which can be assigned as a moderatc for 40 phr of diatomitc added.

Generally, the dried filler showed to be more susceptible to agglomeration, but its agglomerates consist of small er part.icles. Morphology of the rubber composites studied is responsible for their abrasion rcsistance. It confirms our former hypothesis on the importancc of interna!

structure of filler agglomerates on tribological properties

of rubber [11]. It seems likely that the interna! stmcture is more important than the size of agglomerate from the point of view of mechanical strength of filled rubber.

The rubber compositcs studied differ also according to their surface energy - Table 3.

Surface energy calculations also differentiate the composites. Composites filled with "wet" diatomite was te exhibit I ower dispersive component of the surface energy in comparison to materials containing dricd solid phase. It could be the results ofbetter conditions for vul­

canization of rubber matrix, however the differcnce in pH value bctween fillers is not ve1y high - 4,5 for the

"d1y" and 4, 1 for the "wet" one. Higher value of the polar component of surface energy for "dry" diatomite waste

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kompozyty gumowe z odpadową ziemią okrzemkową 7

4(A) 40 phr of diatomite waste/NR

�- 4.1

L

'!)�

,•

., :ł _.i

. 1

8.1�1.

I

Fi

Figurc 4. AJ<M mo r ph ol ogy of the 1'ubber composites filled with diatomite waste:

AJ "wet", BJ "d_ry" (continuecl -pp. 8-lOJ Rysunek 4. Morfologia (AFMJ kompozytów gumowych napełni onych ziemią okrzem­

kową: AJ „mokrą", B) ,,suchą" (cd. - s. 8-10)

ELASTOMERY nr 6 listopad - grudzici1 201 O TOM 14

8 ^kompozyty gumowe z odpadową ziemią okrzemkową

4(A) 80 phr of diatomite waste/NR

l I

TOM 14 listopad - grudzień 201 O

Fig. 4. / Rys. 4. (continuation/ciąg dalszy)

ELASTOMERY nr 6

kompozyty gumowe z odpadową ziemią okt-zemkową 9

4(B) 40 phr of diatomite waste/NR

r 'i'".,._� ... ---.. --:·· .. - ··�- �

f

L.

r

Fig. 4. / Rys. 4. (continuation/ciąg dalszy)

ELASTOMERY nr 6 listopad - grudzień 2010 TOM 14

10 kompozyty gumowe z odpadową ziemią okrzemkową

4(8) 80 phr of diatomite waste/NR

Fig. 4. / Rys. 4. (continuation/ciąg dalszy)

cornposites in cornparison to the "wet" ones can be ex­

plained by a preference to moisture absorption, demon­

sh·ated by the dried filler particles. The higher the filler Table 3. Smface energy and its components, calculated the rubber samples studied

Tabela 3. Energia powierzchniowa i jej sldadowe, obli­

czone dla badanych próbeh gumowych

-�'40phr, 80plu

Pararneter i wet wet

Total surface energy ^I

(mJ/rn²) 19.1

Dispersive component ..

(mJ/m²) 18.1

Polar komponent (mJ/n/) i 1.0

I ' --. -·

20.2 17.3 I

!

rz�·-i

40 phr 180 phr dry dry 24.7 I 32.5

I

21.7

I

3.0 I _{I 9.6}

loading the higher hydrophilicity (polarity) of the cornpo­

site.

4. Conclusions

Diatornite brcwerywaste can be used successfully as a filler in rubber vulcanizates for not dernanding appli­

cations. The amount of filler should not exceed c.a.

40 płu. Higher filler loading does not make any improve­

ment according to the mechanical properties of rubber composites. Their mechanical strength and elongation at break do not change aftcr thermal ageing, no rnatter the filler has been dried or not before incorporation into rubber matlix.

Friction of the rubber composites containing diato­

mite wastcs also does not depend on filler drying, how-

TOM14 listopad -grudzień 2010 ELASTOMERY nr 6

kompozyty gumowe z odpadową ziemią okrzemkową 11

5(A) 40 phr of diatomite waste/NR

�·

l

• !lWl

L--

figurc 5 / Rysunek 5 5(A) 80 phr of diatomite waste/NR

ELASTOMERY nr 6 listopad - gmdzień 201 O TOM14

12 kompozyty gumowe z odpadową ziemią okrzemkową

5(8) 40 phr of diatomite waste/NR

Figure 5 / Rysunek 5 5(8) 80 phr of diatomite waste/NR

l

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kompozyty gumowe z odpadową ziemią okt·zemkową 13

...__.,..._ _ _..._..._..., ... ___ a,.._"_ll_a_"._1* ^ft o ka.�?

,

1 ._I _� ... · _____ .._..._..___,_•-•

5(C) "dry"

I

t. � .·.

\

ELASTOMERY nr 6

UĆQtJt)(l.Cll�

„ I

listopad - grudzień 2010

Figurc 5. SEM analysis of the rubber compo­

sites fillcd with diatomitc waste: A) "t.vet", B) "lb)'", C) cliatomite waste (pp. 11-13) Rysunek 5. M01fologia (SEM) kompozytów gumowych napełnionych ziemią okrzem­

kową: A) ,,mokrą", B) ,,suchą", C) ziemia okrzemkowa (s. 11-13)

TOM 14

14 ^{kompozyty gumowe} z odpadową ziemią oki-zemkową

ever changes with the filler contcnt. Coefficient of fric­

tion is lowcr for higher filler loaded materials.

Despitc "the state" of diatomitc waste is applied does not influence neither mcchanical properties nor the co­

efficient of friction of the rubber compositcs, thcir abra­

sion resistance and the surfa.ce energy depcnd on its prcparatioh. The farmer is bcttcr ·when the filler has bccn dded prior to mixing with rubber. Incorporation of higher amount of"wct" diatomite wastc adverscly cffects abrasion resistance of rubber, whcreas abrasion of rub­

ber composites containing "d1y" filler practically does not dcpend on filler loading. Modification of natura} rub­

ber with "wet" filler rcsults in the vulcanizates of low surface energy. whereas the materials made of"dry" dia­

tomite charactcrize themselves by highcr surface energy.

mainly duc to their high polarity.

Despite encouraging results, prior to the finał dcci­

sion on their application, the rubber compositcs contain­

ing diatomite brewe1y waste should be tcsted for their biodcgradation.

Acknowledgement

The work has been perfom1ed during the scientific stage of Cedric Gay-Berthet, taking place at the Institute of Polymer Materials & Dyes, Faculty ofChemisny, Tech­

nical University of Łódź.

References

1. Sawicki 7:, Bezpieczeństwo Pracy 2003, 7-8, 43.

2. Moraczewski A., Wiśniewski lvf., Wojtysiak J, Recykling 2006, 61 (1), 16.

3. Parasiewicz W, Pyskło L., Magryta J, Poradnik: Recykling zużytych opon samochodowych. IPGum "STOMIL", Pias­

tów 2005, Ch. 4.

4. Nagavallemma KP., Wani S.P., Lacroix S., Padmaja V.V., Vineela C., Bab u Rao M., Sahrawat KL., Vermicomposting:

Recycling wastes into valuable organie fertilize1: Global Theme on Agrecosystems Report no. 8.8. International Crops Research Institute for the Semi-Arid Tropics, Patan­

cheru, Andhra Pradesh, lndia.

5. Adrianowicz E., Janczar J\1., Pietkiewicz J, Fermentation, Fruits and Vegetable Industry 1999, 11, 13-16.

6. Szewczyk KW, Industria l Chemist1y (Przemysł Chemicz­

ny) 2006, M, 1321.

7. Związek Pracodawców Przemysłu Piwowarskiego w Polsce

"Browary Polskie", Najlepsze dostępne techniki (BAT). Wy­

tyczne dla przemysłu piwowarskiego. Ministerstwo Środo­

wiska, Warszawa, kwiecień 2005, p. 15.

8. Bieli11ski D.M., Lipiński P., Wolska B., Jagielski J, Prob­

lemy Ehsploatacji 2006, fil), 131.

9. Owens D.K, Wendt RC., J. Appl. Polym. Sci. 1969, hl 1741.

10. www.nanotec.es

11. Bieliński D.M., Ślusarski L, Dobrowolski O., Głąb P., D_ry­ zek E., Kautsch. Gummi Kunstst. 2004, [il, 579.

,,Poradnik Technologa Gumy"

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