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Juraev Vays Narzullaevich, Independent conpetitor, senior teacher of Tashkent Chemical-technological institute Boborajabov Bakhodir Nasriddin ogli, Independent conpetitor, assistor of Tashkent Chemical-technological institute Vapaev Murodjon Dusummatovich, doctorant of chair'Technology of plastmasses and high-holecular compoundsof Tashkent Chemical-technological institute Ibadullaev Akhmadjon, d.t.sci., professor, chief of chair "Chemical technology of oil and gas processing" of Tashkent Chemical-technological institute E-mail: [email protected]
MODIFICATION OF BITUMEN BU WASTE OF GAS-PROCESSING, GASO-CHEMICAL AND RUBBER INDUSTRIES
Abstract. In this article influence of combinated modification of road bitumen on the complexe of properties of the polymer-bitumen composition has been considered. It was shown increasingof working temperature interval and improvement of the physico-chemical properties of composition and also optimal composition of rubber-bitumen composites for car roads of sharply continental climate was elaborated.
Keywords: bitumen, gasopyrolysed resin, resin crumb, modified carbon, liquid rubber, composition, technology, road bitumen.
Introduction. In road branch the road bitumen men concluded inusing of waste of gaso-processing,
is integral part. It is used for bondind and cohesion gaso-chemical and rubber industries as modifiers
of mineral materials, introducing in tire-coverof car owing their low cost in comparasion with polymer
roads. In process of expluatation tire-covers didn't modificators. Also one of important factors of utili-
always can to preserve integrity during ofdemanded zation ofwaste at bitumen modification is ecological
period of time owing insufficient quality of bitumen factor namelly decreasing of unused industrial waste. [1]. By this reason numerous investigations have In thisworkpossibility of using gaso-pyrolysis res-
been carried out with aim of perfection of base- in (GPR), rubber crumb (RC) and modified carbon
physico-chemical indixes of road oil bitumen. Ac- (MC), which is a secondary raw material at acetylene
tual task in this direction is drawing in the industrial production, in modification of composition of bitu-
production of road materials home waste and also men compositions has been investigated. by-productsof different manufactures. Gaso-pyrolysis resin - solid substance of black
Objects and methods of investigation. The colour without odour, it's composition didn'tstable
most perspective method of modification of oil bitu- and has depended onpyrolysis raw material (Table 1 ).
Table 1.- Chemical composition of gaso-pyrolysed resin
Number of carbon Akcanes Dienes Olephynes Cycloalcanes Arenes Inall
5 0.8 0.89 4.91 0.19 0 6.79
6 0.22 0.41 3.87 0.41 32.94 37.85
7 0.25 0.14 0.84 0.45 11.23 12.91
8 0.12 0.08 0.18 0.48 9.75 10.61
9 0.04 0.1 0.04 0.15 7.56 7.89
10 0.03 0.11 9.07 0.4 5.23 14.84
11 0.18 0.69 2.95 0 0.47 4.29
12 0 0.15 1.84 0 0 1.99
Bcero 1.64 2.57 23.7 2.08 67.18 97.17
Rubber crumb - is strong zeduce to fragments Modified carbon - carbon-containing secondary
rubberfractions ofwhich in process ofprocessing can raw materials which has differedby chemical compo-
sition from nown sorts of low-structural technical carbon, T 900, T 701, T 705, P 803 (table 2) namely by high content of oxygen and hydrogen.
differ by form and dimensions ofparticles. Howeverin final result, all these fractions have preserved the base characteristics of initial material: elasticity and molecular structure. For obtain of rubber crumb tire -covers unfit for usinghave been used as raw materials.
Table 2.- Elemental composition of MC and some sorts of technical carbon
Name of index Content,%
MC T 900 T 701 T 705 P 803
Carbon 88-90 96-99 96-98 96-98 97-99
Hydrogen 3-4 0.3-0.5 0.4-0.6 0.6-0.8 0.4-0.6
Oxygen 6-7 0.1-0.2 0.3-0.5 0.3-0.5 0.1-0.2
Sylfer - 0.1 0.3 0.3 0.2
Ash content 0.8-0.9 0.1-0.2 0.4-0.6 0.4-0.5 0.4-0.5
Investigation of extraction products of carbon-containing secondary raw materials has witnessed about presence 12% of organical compounds apre-tizated on surface of carbon particles. Following element composition has been determined (%): C-92.11; H-5.70 and O-2.19. The formula of the extract is C54H40O.
Average-numeral molecular mass of thisraw-material is equaled 700 according to data by gel-chromatography. IR-spectroscopical invitigation has shown that products of extraction are combination of condensated aromatical and paraffino-naphthene hydrocarbons and also oxygen-containing carbonyl
compounds. On this in particularappearance of char-acteristical bands ofabsorption in ranges of3050 sm-1 (valent vibrations of C-H - bonds of aromatical ring), 2860, 2930 and 2975 sm-1 (valent vibrations of C-H - bonds of methyl and methylene groups) has been indicated and also bands of absorption at 1710 sm-1 (> C = O) in carbon chain.1730 sm-1 (in resins of asphaltenes); in range1500-1600 sm-1 correspond to valent vibrations of > C = C < bonds forming at thermal cyclization and oligomerisation of acetylene. PMR-spectrums have indicatedon the presence of protons at d = 6.70; 6.85 and 7.10 ppm, typical for aromatic structures and their derivatives.
Extragatedproduct has given narrow individual signal of EPR with concentration PMC = 1 • 1014 spin/g. It is necessaryto note that results of mass-spectromet-ricalinvestigation also have confirmed the proposed composition of extractionproducts. Carring out investigationhasshown that carbon-containing secondary raw-material is anMC surface of which has microcapsulated by oligomerical oxygen-containing compounds. Thickness of oligomeric cover calculated by values of specific geometrical surface was equiled 50-60 E.
MC is characterized by higher value of oil and iodine numbers, what is conected with roughness of surface (S = 25-30 m2/g) and presence of polycon-jugated systems. Also it is necessaryto note a high degree of dispersion.
Electronno-microscopicalinvestigationhaswit-nessed that structure of particles of MChas different insome degreefrom particles of initial technical carbon: characteristical for technical carbon clear borders of spheroidal form of particles are absented.
However after thermotreatment at 1573 K during 1 hour (in nitrogen atmosphere) it's structure has approachedtostructure of technical carbon and at thismiddle surface diameter of particles has decreased from 30.6 to 21.5 nm. Increasing ofspecific geometric surface from 20.3 to 29.3 m2/g was observed what isconnectedwith process of dispergation of more large particles owing to evaporation mois-
The base characteristics of prepared samples of bitumen astringent havebeen analysed by following methods: thermal heat capacity - by method "Ring and Ball"; low temperature properties - by the method of determination of fragility temperature - by method Praasy, index of penetration - by
ture and othersaccompaining compounds in process of thermotreatment.
By comparision of results of rontgeno-graphical investigation of initial and MC it was determined that for they is typical presence of impuritiesof crystalline phasewhatcan beattributed to hydrocarbons containing in iheircompositions (12%). The base phase of MCwas phase having typical turbostrated structure what is proved by typical characteristical asymmetrical profile of diffractional bands. Diffrac-trogramof MC is differencedfromsuch of technical carbon by low regulation of turbostratedbundles of layers about which value J002/J002 has witnessed.De-gree of regulation of MC (parameter J002/J002) has increased athigh-temperature (973-1573 K) treatment. Dimensions of ranges of cogerated distance of amorphous phases have been determined; dimen-tionsof layers are in limites 15-20 E.
Carring out investigations have allowed to suppose that structure ofMCis probably is middle stage of process of formating soot structures. It is possifle to suppous that using of carbon filler appretirated by oligomeric cover consisting from systems ofconju-gation has allowed to developein principle new approach for creation polymer-bitumen compositions with improvment properties.
Bitumen oil-ro ading (BOR) of marks 40/60 and 50/70 has been used in this investigation and their initial characteristics are presented in (table 3).
method ofdetermination of depth of needle penetration; plasticity - by method ductiality; reduction -by method of determination of elasticity; adges-sion of bitumen - by method passive cohesion with mineral materials.
Table 3.- Initial characteristics BOR40/60 andBOR50/70
Mark Temperature of softing by "Ring and Ball", °C Temperature of fragility by Fraasy, °C Penetration at 0 °C Penetration at 25 °C Duration at 0 °C, sm Duration at 25°C, sm Elasticity at 0 °C,% Elasticity at 25 °C,%
BOR40/60 59.35 -22.4 12.5 40 7.6 24 21.05 33.3
BOR50/70 58.5 -24.8 31 50 10.4 30.7 5.7 18.6
Obtained results and their discussion. Samples of modified bitumen were prepared; base characteristics of bitumen were determined and on this base optimal values of it'sindexes of qualityby two samples of bitumen compositions were take away (table 4). From data of table 4 it is shown that modifining additionshave im-provemen the base index of heat-stability-the softening temperature. Introduction of modificators has decreased index
of penetration bothat 25 °C and 0 °C, owing tow-hichchangingof mark of initial bitumen was carried out. Temperatureof fragility is one of the important index of low-temperature properties of compositions. It was determined that only for first sample (3% GPS + 5% liquid rubber) improvement of this index has been observed what can be explained by presence of polymer in common with GPS in modified addition.
Table 4.- Basical properties of modified samplesof bitumen
Samply Temperature of softing, °C Temperature of fragility, °C Penetration at 0 °C Penetration at 25 °C Duration at 0 °C, sm Duration at 25 °C, sm Elasticity at 0 °C,% Elasticity at 25 °C,%
BOR40/60+3% GPS+3% liquid rubber 61.05 -26.3 12 23 6.7 16 11.76 42.18
BOR50/70+20% of rubber cruimb 60.85 -19.3 25 36 6.6 14 10.6 21.7
B0R50/70+7% MU 60.2 -21.4 27 38 6.1 12 8.3 21
Index of tensilityfor all samples was lower than forinitial bitumen what can be explained by an increas-ingof viscosity of bitumen composition at introduction of additions. Improvementof index of elasticity at 25 °C and 0 °C for all samples was observed but however thisindex wasbest at using GPS, liquid rubber jointly with GPS and MC in a modified addition.
Also in this work it was carried out determination of adhesium by method of "passive cohesion". Inves-tigationhas shown that compositions with modified additions has corresponded to GOST by full cover of surface of mineral material by bitumen film after exposition of sample in boiling distilled water during 30 min. and alsoall samples ofbitumen bindings have carried out tests on cohesionwith mineral materials.
Republic of Uzbekistan is characterized by charp continentaly climate, high solar activity in the summer period and low temperatures in wintry period. By this reason at the same time with data presented earlierthe frost-resistance of materials is also very im-
portant characteristic. Obtainedresults have shown that samples undergoneto testing after 30 cycles of freezing and thawing have decreased strength at pressing on value 14% and lest from initial. At inspection destruction of samples wasn't observed. Coefficient of frost-resistance at thiswasequaled from 0.80 to 0.95. These data havewitnessed about sufficient frost-resistance of testing samples of asphalt-concrete.
It is necessary to note that used regimeof testing on frost-resistance was more hard in comparison with realregime of covers exploitation. Didn't exclude that destruction effect from charpchanging of temperature of samples can bedisplay in higher degree than at work in real conditions of exploitation.
Carring out investigationshave witnessed a considerable heat-frost resistance of asfalto-concrete on the base ofrubber-bitumen composites of following composition: B0R40/60 (B0R50/70) - 7%, GPS -1-3% from mass of bitumen, liquid rubber - 1-3%
from mass of bitumen and rubber crumb - 20-25% from total volume and also mineral additions.
Resume. Thus in work possible using ofwaste gas-processing, rubber industry and liquid rubber as modifying additives to bitumen B0R40/60 and B0R50/70 has been determined. These modifiers haveallowedto
increase work temperature interval of bitumen and also it's elasticity but at thisthey have decreased index of penetration changing markof initial bitumen. According to carring out investigatons the optimal composition ofrubber-bitumen composites for car roadsof charp continental climate has been elaborated.
References:
1. Vapaev M. D., Boborazhabov B. N., Teshabaeva E. U., Ibadullaev A. S. Road compositions based on modified bitumens // Austrian Journal of Technical and Natural Sciences No. 9-10.2018.- P. 34-37.
2. Boborazhabov B. N., Vapayev M. D., Akhmadzhonov S. A., Ibadullayev A. S. Issledovaniye svoystv dorozhnykh bitumov, modifitsirovannykh kombinirovannymi dobavkami // Tosh DTU khabarlari Ilmiy-tekhnikaviy va amaliy jurnal - No. 3.- Toshkent, 2018.- P. 167-172.
3. Ibodullayev A. S., Seydabdullayev Y. A. O. Issledovaniya uglerodistogo materiala i yego vliyaniya na svoystva kabel'nykh rezin // Jurnal "Kompozitsionnyye materialy".- Tashkent, 2015.- No. 3.- P. 25-28.
