CC BY
34
DOI: http://dx.doi.org/10.20534/ESR-17-5.6-88-92
Shykhaliyev Kerem Seyfi, Professor
of "Orgonicheskie substances and NAVAL technology» Azerbaijan State University of oil and Industry E-mail: [email protected]
EXPLOITED THERMOPLASTICS BASED COMPOSITIONS
Abstract: Exploited polymer materials, binders-functional groups containing oligomers and polymers, compositions based on filler mixtures.
Goal of the work: research of scientifically justifiicated secondary threatment and recovery of exploited polymers, study of their structure indices changing during the exploitation process, selecting of modificators, modification methods and technological regimes according to the obtained results and determination of composition materials indices based on them and their use fields.
Research have been carried out using chemical, physico-mechanical methods and devices analyzing polymers.
Analysis of scientific information on the theme has been carried out as a result of research. It has been shown that secondary treatment of polymer waste is the most efficient direction from economic and ecological point of view.
Keywords: thermoplastics, polyethelen, polystyrol, polypropilene, modification, composition rubber mixture, secondary threatment, modificator, filler, vulcanization, structure, functional group polymer, functional group oligomer
Research object: exploited polymer materials, binders-func- ous compositions based on exploited polymers and their content and
tional groups containing oligomers and polymers, compositions based on filler mixtures.
Goal of the work: research of scientifically justifiicated secondary threatment and recovery of exploited polymers, study of their structure indices changing during the exploitation process, selecting of modificators, modification methods and technological regimes according to the obtained results and determination of composition materials indices based on them and their use fields.
Research have been carried out using chemical, physico-me-chanical methods and devices analyzing polymers.
Analysis of scientific information on the theme has been carried out as a result of research. It has been shown that secondary treatment of polymer waste is the most efficient direction from economic and ecological point of view.
Physico-chemical, mechanical and rheological properties of polyethylene and polystrene waste have been studied. Analysis of properties of exploited polyethylene and polystyrene showed that it is impossible to change polymer waste to the raw material which can be used in secondary treatment without modificating them and it is connected with structural-chemical changes happening in macromolecules in treatment process of polymer waste and natural climate condition during the exploitation.
Rheological properties of exploited polyethylene and polystyrene wastes have been studied with capillary viscosymetry method. It has been determined that increase of flow indices of polyethe-lene and polystyrene wastes melt causes reduce of their viscosity and molecul mass, it makes better secondary treatment of exploited polyethylene and polystyrene and shows possible treatment of thermoplastics by traditional methods.
Nature materials and industry waste have been chosen on the bases of local raw sources. they are used as filler for preparing ofvari-
properties have been studied.
Efficiency is obtained due to solution of economic and ecological problems.
Their application field is to use them in substituting initial raw material by new property materials obtained from secondary treatment polymer of wastes contaminating environment and formation of new compositions.
Discussion of the obtained results.
Some low-indices of the compositions obtained on the basis of ethylene-propylene copolymer limit their use in the production of tire and rubber-technical items. By adding polar substances or polymers to the mixture of ethylene-propylene copolymers with other polymers it is possible to improve combined mixing and combined vulcanization and extend application spheres [1-4].
When adding a, w-methacril (-bis-triethelenglycol phtalat) — (OEA-9) plasticizer to copolymer improvement of their some indices is observed. Its resistance to tearing increases, durability in multi tension, adhesion of the composition to the metal, chemical stability raise and swelling degree in benzole, benzene-benzole mixture reduces. With this purpose rubber composition has been prepared on the basis of ethylene-propylene copolymer with oligoetherakrylate mixture.
Compiling of rubber mixture receipt.
Physico-mechanical and exploitation indices (technical properties) of the rubber mainly depend on the content of rubber mixture.
In the research of modification process of ethylene-propylene copolymer based rubbers filled with oligoetherakrilate the content of rubber mixture has been determined first. For producing rubber items first of all receipt of rubber mixture is compiled.
When compiling rubber mixture receipt the quantity of all ingredients is indicated together with their names.
Influence of each ingredient on the rubber mixture and also its economic efficiency must be considered. Thus, processed rubber with the technical conditions be obtained cheaper.
Ingredients should be written in the following consequence in the receipt: first rubber, then sulphur, accelerators, activators, softers, fillers, substances against aging, dyers and supporting substances.
The content of the studied rubber composition consists of the following components:
Ethylene-propylene rubber
- OEA-9;
- Sulphur;
- Stearine acid;
Table 1. - Content of modificated and unmodificated
100 mass rubber has been used for obtaining rubber mixture.
Mechanico-chemical modification of elastomers makes it possible to improve their phisico-mechanical production properties by simple and effective method and to widen their application fields. In this case special complex equipment isn't required and technical items with necessary properties are obtained in the traditional treatment.
Ozone is the most agressive factor for rubber based on the common direction. Some folds appear on the resin coat due to ozone influence. That's why protecting of rubbers atmosphere influence is urgent and covering of rubber surfaces with polymer coating is one the solution ways of the problems. Preparing and research of compositions for protection coating especially based on elastomers are paid more attention [5-7].
From this point produced ethylene-propylene rubber is great interest. This rubber has a number of complex valuable properties like durability to atmosphere, heat and chemical influences. But disadvantages of the ethylene-propylene rubber like low durability to water and adhesion limit preparing protect rubber coatings and the research of the elimination ways of this disadvantage waits its solution. Research works in the direction of modification of ethylene-propylene with monomers and polymers containing various functional groups have been carried out recently [8-12; 10].
Preparing of rubber mixture in the production of rubber items is one of the main technological processes. Ingredients as powder, solid and liquid forms must be mixed with rubber simultaneously, and equal distribution of these ingredients in the rubber must be supplied. That's why obtained rubber mixture must be homogenous according to its content.
Quality of the researched composition mainly depends on rubber properties and wetting of ingredients in the rubbers.
- Tiurum (TMT);
- Kaptax;
- ZnO;
- Technical carbon (P-234).
Ingerdients in the content of this composition: oligoetherakrylate (OEA-9) modificator, sulphur-vulcanizating agent, stearine acid as softener, tiurum (TMTS)-tetramethyetiuramdisulphide and kaptaxs as accelerators, zink oxide is used as activator ofvulcanization process in the obtaining of rubber mixtures, technical carbon is used as filler.
Various contents of rubber compositions have been taken. Rubber composition without modificator (OEA-9) has been prepared for comparison. ethylene-propylene copolymer based compositions.
Precise measuring of the components used for preparing of mixture on the basis of rubber and ingredients, consecutive mixing of ingredients with rubber and the temperature influence on the mixture properties.
Under the laboratory condition preparing of rubber mixture has been carried out in the laboratory mixer.
Mixing regime is determined according to the type, volume of stirring installation, to the rotation speed of the rotor or shafts and rubber mixture content.
Mixer must be operated by defining the distance between shafts 0.2-0.3 mm with regulating screw.
Stirring process has been carried out in mixer at 40-60 ° C within 25 minutes.
During the stirring introduction of ingredients to the rubber is carried out in the following consequence: softeners, vulcanization accelerators, activizators of the accelerators, filler, special ingredient (MGF-9) and vulcanization agent.
Regime time starts at the beginning of mixing process. Rubber is gradually loaded in the form of pieces into the space between shafts from the big gear wheel and this operation repeats 5-6 times. Then the distance increases 1-2 mm and rubber plastics in the front shaft at the same time other ingredients are added. Ingredients are gradually poured on the rubber reserve along the length of front shaft and stirred at the necessary time.
While preparing the mixture shaft temperature is checked 2-3 times with ray thermo pair. Mixture passing through the shafts in the form of paper is coaled in the bath in chalk or kaolin suspension.
Vulcanization of rubber mixtures
Rubber mixtures must be vulcanizated for obtaining friction resisting, solid, high elastic vulcanizates having high durability indices.
Name of components Quantity, m.p
I II III IV V VI
SKEP-60 100 100 100 100 100 100
Stearine acid 1,0 1,0 1,0 1,0 1,0 1,0
Tiurum (TMT) 1,5 1,5 1,5 1,5 1,5 1,5
Kaptaxs 0,5 0,5 0,5 0,5 0,5 0,5
ZnO 5,0 5,0 5,0 5,0 5,0 5,0
Technical carbon (P-234) 50,0 50,0 50,0 50,0 50,0 50,0
Sulphur 2,0 2,0 2,0 2,0 2,0 2,0
OEA-9 - 0,5 1,0 1,5 2,0 2,5
It is known that complex physico-chemical processes taken place in the presence ofvulcanizating agents in the mixture in a definite temperature that's mechanico-chemical modification process proceeds. As a result, items with any properties are obtained.
Vulcanization process in the prepared rubber mixtures has been carried out at 155 ° C temperature and within various time period (10-40minutes).
Physico-mechanical and exploitation indices of vulcanizates have been investigated (80).
Kinetics ofvulcanization process of the mixture of ethylene-pro-pylene copolymer and ethylene-propylene+OEA-9 has been studied.
Durability level, conditional tension at 100% and 300% extension, tear resistance, strength on TM-2 and other indices of the vulcanizates obtained at various temperatures in tensile in TM-60 type cutting machine. The temperature of the optimal regime ofvulcanization process has been determined 153 ± 2 and 25 minutes
Dependence of consumption quantity of SKEP-60+ OEA-9 and 2-SKEP-60 based compositions in capillary reometr on the time at 153±2 ° C temperature has been studied. At each 30 minutes consumption quantity of the composition flowing in one capillary is taken and weighed. According to the taken results dependence graphic of consumption quantity on the time has been set up.
The goal is determination of zol fractions ofvulcanizate samples given in table 1. That's why quantity of the plastificator (OEA-9) in chemical process has been determined. That's why vulcanizates were extracted in OEA-9 solution (benzol) within 26 years and dried till the constant weight.
Analysis of the obtained results shows that vulcanization process of SKEP-60 + OEA-9 (1.0 m. p.) composition at a given temperature ends within 14 minutes. Vulcanization time of the composition based on SKEP-60 ends within 18 minutes. These results prove again that complex ether group and 2 bond a, w-metacril-(bis-triethylenglycol-phtalat)-OEA-9 is used as a binder and also can be polymerized in the mixture. These indices prove the results ofvulcanization kinetics on the dependence of durability level on the time.
Adding of low molecule additives into oligoetherakrilat-OEA-9 mixture causes reduce of mixture viscosity. Physico-mechanical properties of compositions based on SKEP: OEA mixture improve. These mixtures are used in tyre and rubber-technical item production. Compositions based on the given mixtures in comparison with the compositions based on SKEP-60 have higher adhesion ability, low swelling level in benzene-benzole mixture.
Table 2. - Physico-mechanical properties of rubber mixture based on ethylene-propylene copolymer filled or unfilled with oligoetherakrilate
№ Indices Rubber, mixture
I II III IV V VI
1. Tensile strength level, MPa 20,7 21,1 24,6 21,5 18,5 17,3
2. Conditional tension in 100% extension, MPa 3,6 3,8 4,1 3,7 3,4 2,8
3. Conditional tension in 300% extension, MPa 13,6 13,9 14,2 13,5 12,9 12,1
4. Relative extension, % 380 395 410 430 450 480
5. Relative residue deformation, % 14 14 14,1 14,6 14,8 15,0
6. Breaking strenght, kN/m 32,9 33 35,8 33,6 33,1 32,7
7. Elasticity on bound, % 40 40 40 39 37,5 36
8. Hardness on TM-2, c. u. 70 70 69 68,5 68 67,5
9. Bond hardness with metal, MPa 1,40 1,50 1,65 1,54 1,52 1,40
10. Fatigue resistance in multi tension (e din = 200 %, v=250 rot/min.) 1,25 1,50 1,92 1,98 2,0 2,1
11. Aging heat coefficient at 393 K temperature, within 140 hours, On fp On e p 0,76 0,41 0,76 0,42 0,75 0,43 0,73 0,44 0,69 0,48 0,67 0,50
12. Swelling level at 296 K temperature, within 48 hours (in benzine) 130,5 115,0 90,8 110,7 115,2 120,5
Small quantity of plastificator OEA-9 makes possible to obtain diaphragm compositions having improved properties based on SKEP-60 and butyl rubber. For a long time in the industry exploitation time of diaphragms vulcanizate of the compositions added into OEA-9 is 25-26% is more than the diaphragms from butyl rubber (BR). Thus on the basis of BR diaphragm — 100 tyres after
being vulcanizated, the diaphragm rubber becomes soft (tarred), and it complicates extraction of tyre out of diaphragm and as the diaphragm sticked to tyre it is damaged, and another defect forms a layer inside the diaphragm tyre, that's it is not restored completely after the complete deformation. To liquidate such problems the receipt in the following content has been prepared (table 3).
Table 3. - Modificated ethylene-propylene and content of BR based compositions
Name of components Quantity, m. p.
I II III
SKEP-6 100 100 100
BR
Stearine acid 1,0 1,0 1,0
Amborol SP-137 6,7 6,7 6,7
Petrolatum 7 7 7
ZnO 5,0 5,0 5,0
Technical carbon (P-514) 35,0 35,0 35,0
Technical carbon (P-234) 20,0 20,0 20,0
Sulphur 2,0 2,0 2,0
OEA-9 - 0,5 1,0
Diaphragm rubber mixture has been prepared in laboratory mixer at 40-60 ° C temperature within 20-25 minutes. Prepared rubber mixture being kept 6-8 hours at the room temperature has
Table 4. - Physico-mechanical properties of SKEP-60
been vulcanizated. Physico-mechanical indices of vulcanizate have been given 4.
diaphragm rubber based on BR modificated by OEA-9
№ Indices Rubber mixture
1 Tensile strength level, MPa 10,5 11,3 12,6
2 Conditional tension in 100% extension, MPa 4,1 4,5 4,8
3 Conditional tension in 300% extension, Mpa 7,9 8,5 8,6
4 Relative extension,% 672 640 645
5 Relative residue deformation,% 26,4 25,1 25,5
6 Breaking srtength, kN/m 45,3 54,6 55,5
7 Elasticity on bound,% 6,5 7,1 7,1
8 Hardness on TM, c. u. 54 52,5 53,5
9 Bond hardness with metal, MPa 1,45 1,50 1,60
10 Fatigue resistance in multi tension (e din 200%, v = 200rot/min) 1,56 2,65 2,75
11 Heat aging coefficient at 393k temperature, within 140 hours, On fp On e p 0,59 0,46 0,62 120,0 0,63 0,58
12 Swelling degree at 296 K temperature within 48 hours (in benzene) 120,5 120,0 120,8
As it is seen from the table, when adding SKEP-60 modificated by OEA into the BR based composition, its exploitation indices and also aging from heat increases.
From the carried out research results it can be determined that plastificator a, w-methacril (bis-triethylenglycol phtalat)-(OEA-9) reducing vulcanization, make possible to improve physico-mechanical and exploitation indices ofSKEP-60 and its other elastomer mixtures.
Conclusion
1. Unsufficient properties of ethylene-propylene copolymer based compositions limit their use in tyre and rubber-technical items. Ethylene-propylene copolymer has been modified with oligoetheracrilate (OEA-9) to improve joint mixture and joint vulcanization of copolymer with other components.
2. Convenient receipt of rubber mixture has been worked out, and homogenous mixture has been prepared due to this receipt on laboratory mixer (at 40-60 ° C, within 20-30 minutes).
3. Prepared rubber mixture has been vulcanizated at the vulca-
nization shop at Baku Rubber-Technical Items factory. Optimal vulcanization regime has been determined (150 ° C temperature, within 20 minutes).
4. Physico-mechanical and exploitation properties (tensile strength level, conditional tension in 100% extension; conditional tension 300% extension, relative extension, relative residue deformation, breaking strength, elasticity on bound, hardness on TM-2, bond hardness with metal, fatigue resistance in multi tension, heat aging coefficient at 393 K temperature, swelling level within 48 hours, strength to agressive mediums) have been studied.
5. Adding of definite quantity of OEA-9 cycle oligoetheracrilate plastificator into various mixture compositions improves properties of vulcanizate, including improve of mutual dispersion of components in the mixture. Introduction of plastificators increases strength to multi tensile (E ten =200%, V=250 rot/min) from 1.500 to 1.92 thousand cycles bond hardness with metal. These indices are higher than the indices corresponding to tyre and diaphragm rubber.
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