RU2496812C1 - Polymer-bitumen binder and method for production thereof - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: binder contains bitumen and a polymer component consisting of industrial oil which is nano-modified with single-wall carbon nanotubes without purification from impurities of carbon and metal nanoparticles, and a polymer. The polymer component used is thermoplastic elastomer DST-30R-01. Components are in the following ratio, wt %: DST-30R-01 - 1.1-3.4; industrial oil - 2.2-9.4; single-wall carbon nanotubes - 0.001-0.03; bitumen - the balance. The method of producing the binder involves adding the polymer component to bitumen while stirring. Before adding to bitumen, the polymer component is prepared by mixing the single-wall carbon nanotubes with industrial oil at temperature of 100-120°C and then adding the polymer, after which the obtained mixture is added to bitumen while stirring at 120-160°C.

EFFECT: obtaining highly homogeneous bitumen binder, having improved physical and mechanical properties while reducing consumption of polymer and industrial oil.

2 cl, 2 dwg, 2 tbl, 5 ex

Description

The invention relates to materials used in road, airfield and civil engineering, in particular to polymer-bitumen binders for the construction industry, and methods for their preparation, can be used in roofing, waterproofing and airtight seams, as well as in the preparation of organic-mineral mixtures.

Known binder for road surfaces, obtained by mixing 85-98 wt.% Bitumen, 15-2 wt.% Branched or linear styrene block copolymer at 200 ° C-250 ° C for 15-40 minutes (EP No. 0458386, CL. C08L 95/00, 1972).

In addition, it is known astringent for road surfaces, obtained by introducing into the bitumen at a temperature of 80-200 ° C and continuous stirring divinylstyrene block copolymers of the SBS type, taken in an amount of 0.1-10% by weight of bitumen in the form of 5-25% - solution in light solvents (SU, A, 272881).

These binders have a sufficiently high strength and elasticity, however, in the case when there is no solvent in the binder, a good combination of the polymer with bitumen is not observed, i.e. the structure of the binder is not homogeneous, despite the fact that the process of its preparation was carried out at a temperature of 200-250 ° C. The inhomogeneous binder structure causes cracks in the road surface at temperatures below minus 10 ° C.

The closest technical solution to the present invention is a binder for paving and a method for its production (RF patent No. 2038360, class C08L 95/00, 1995), containing bitumen, block copolymers of alkadiene and styrene and industrial oil in the following quantitative ratio, wt .%:

bitumen 44.4-98.0 block copolymers of alkadiene and styrene 0.1-22.3 industrial oil 1.9-33.3

Moreover, before introducing into the bitumen, the copolymer is mixed at 80-160 ° C with industrial oil, after which the resulting mixture is introduced with stirring at 110-160 ° C into bitumen.

The invention allows to obtain a binder that meets the parameters of the requirements for binders for road surface. However, it is not possible to achieve complete homogeneity of such a binder, since the affinity of industrial oil, consisting mainly of naphthenic hydrocarbons, to block copolymers of alkadiene and styrene is low. The binder has a relatively low values of elongation and elasticity, as well as poor adhesion.

A distinctive feature of the claimed invention is to obtain a binder, characterized by high rates of cohesion, elasticity, adhesion, softening temperature and low temperatures of brittleness. Achieving the stated indicators is carried out by changing the viscosity of industrial oil by introducing single-walled carbon nanotubes (SWCNTs) into its composition, which allows one to obtain the indicated positive effect with a decrease in the polymer content in the polymer component.

In terms of the method for preparing a polymer-bitumen binder, the hallmark is the production of a homogeneous binder with a uniformly distributed polymer in a nano-reinforced matrix. The result is achieved due to the sequential multifactorial mixing of the components during the preparation of the binder.

The basis of the claimed invention is based on the following tasks: by changing the composition and varying the technological parameters during the preparation of the target product, create a uniformly nano-reinforced matrix of the polymer component with its subsequent introduction into bitumen and obtain a highly homogeneous bitumen binder with high physicomechanical properties while reducing polymer and industrial consumption oils.

The technical result of the claimed invention in terms of polymer-bitumen binder is to determine the necessary components that make up the composition of polymer-bitumen binder material, as well as their ratio in this composition, ensuring the achievement of the above properties.

The achievement of the specified technical result is ensured by the fact that the binder contains bitumen and a polymer component consisting of industrial oil and a polymer, characterized in that the polymer component contains a polymer of the class of thermoplastic elastomers (block copolymers of butadiene and styrene like SBS) - DST-30R-01 , solvent plasticizer - industrial oil, nanomodified by single-walled carbon nanotubes (SWCNTs) without purification from impurities of carbon and metal nanoparticles in the following ratio of components in, wt.%:

DST 30R-01 1.1-3.4; industrial oil 2.2-9.4; SWCNT 0.001-0.03; bitumen rest.

In the case of the preparation of a polymer-bitumen binder with a content of components not included in the above range of values, the claimed technical result is not achieved due to the fact that with an increase in the content of SWCNTs in the polymer component, the viscosity of the binder increases, this leads to a decrease in its extensibility and reduction of the ductility interval.

The compositions of the prepared binders samples are shown in Table 1, and their characteristics are shown in Table 2. Table 1 shows the data with the same solvent-plasticizer content for an adequate comparative assessment of the binder compositions and determination of the effect of SWCNTs.

Table 1 The composition of binders No. / No. Composition, wt.% Arr Bitumen Plasticizer solvent Nanomodifier Styrene-butadiene-styrene Industrial oil I-40A SWCNT DST-30R-01 one 92,970 5,0 0.3 2.0 2 91,970 5,0 0,03 3.0 3 92,998 5,0 0.002 2.0 four 91,998 5,0 0.002 3.0 91,999 5,0 0.001 3.0

table 2 Characteristics of binder samples Binder Samples (No. / No.) Requirements Famous Indicators one 2 3 four 5 GOST R astringent 52056-2003 (prototype) PBV60 Needle penetration depth, 0.1 mm at 25 ° C 72 73 69 75 71 60 126-151 at 0 ° C 40 26 54 57 49 32 70-88 The softening temperature of the ring and ball, ° C 59 61 59 63 59 54 51-61 Fass brittle temperature, ° C -21 -26 -27 -33 -thirty -twenty (-26) - (- 31) Grip with Corresponds to sample No. 1 With marble marble or With marble - 5 points - 5 points sand * With sand - 4 points With sand - 4 points Flash point ° C 251 - 246-260 Stretch, cm at 25 ° C 37 31 30.5 71 75 25 26-69 at 0 ° C eleven fourteen 14.5 16 19 eleven 21-60 Elasticity, cm at 25 ° C 82 89 90 93 87 80 58.1-91.8 at 0 ° C 73 76 85 92 85 70 75-82.5 Cohesion, kg / cm ² 10 eleven 13 fifteen 10 - - Plasticity Interval, ° C ** 80 87 86 99 89 - - * - adhesion to marble or sand is determined according to GOST 11508-74 ** - the ductility interval is defined as the difference between the softening temperature and the fragility temperature

As can be seen, the proposed binder surpasses the prototype in terms of elongation, elasticity, adhesion, brittleness temperature for the entire range of binder composition; this achieves complete uniformity of the binder. The homogeneity of the distribution of the polymer and the SWCNTs in the polymer component was evaluated by micrographs, Figs.

When preparing a modified polymer component with a content of 0.03% SWCNTs, the following is observed: a polymer content of 2% allows to obtain a binder with property indicators that meet regulatory requirements, however, these indicators are borderline, an increase in the number of SWCNT modifier in the mixture changes such properties of the binder as elongation and the temperature of fragility, in the direction of lowering and inconsistency GOST R 52056-2003. When the polymer content is increased to 3% in the binder sample No. 2, the penetration indicators at 0 ° C do not meet the requirements of GOST R 52056-2003.

The inventive binder is characterized by the following indicators: the penetration depth of the needle at 0 ° C significantly exceeds the requirements of GOST R 52056-2003, moreover, the difference between this indicator, determined at a temperature of 25 and 0 ° C in compositions No. 3-No. 5, is small and is 30 -twenty%.

In accordance with the recommendations of GOST R 52056-2003, the difference between the depth of penetration of the needle at test temperatures of 25 and 0 ° C is 87%, the dynamics of the depth of penetration of the needle depending on the temperature of the test in the invention, taken as a prototype, is 80-70%. It is known that the penetration depth of a needle at 0 ° C characterizes the plasticity of binders at low air temperatures and is their operational characteristic, indicating deformability and, therefore, crack resistance of asphalt concrete. Thus, the higher the depth of penetration of the needle into the binder at 0 ° C, the more frost-and crack-resistant asphalt concrete based on it will be.

An analysis of the temperature of brittleness justifies this assumption. A comparison of elasticity data shows that when the DST content is 2-3% by weight in a polymer matrix nano-reinforced with 0.002% SWCNTs, the elasticity of PBB reaches its highest value - more than 90% at 25 ° C and more than 80% at 0 ° C.

The cohesion of the polymer binder changes significantly. When testing the initial BND 60/90 bitumen, the cohesion value determined on a cohesiometer device (ASTM) was 8 kg / cm ² , whereas a binder prepared without modification of SWCNTs and with a polymer content of 3% -10 kg / cm ² .

A further decrease in SWCNTs in the binder does not provide the claimed technical result due to the lack of a significant effect from nanomodification of the polymer component.

On the example of binder samples No. 3 and No. 4, containing 2% and 3% polymer, respectively, we can conclude that for the preparation of 60 grade PBB that meets the requirements of GOST R 52056-2003, 2% DST is sufficient, while according to the traditional recipe this content ranges from 3-4%. Thus, by varying the industrial and nanomodifier oil content, it becomes possible to reduce the content of the DST polymer in the binder.

The introduction into the bitumen of the polymer in the form of a solution allows to accelerate the process of obtaining a binder, to lower the temperature regime of the production process, ensuring the formation of a uniform structure, the required crack resistance of the binder.

In addition, the inventive bitumen binder is characterized by a flash point above 220 ° C, which eliminates the explosion and fire hazard in the manufacture and use of such a binder.

Varying the component composition of the declared bitumen binder allows you to adjust its properties in a given direction (increase in heat resistance / fragility, etc.) and successfully use it in various climatic zones.

The technical result of the claimed invention in terms of the method is the development of a method (process) for the uniform distribution of SWCNTs and the creation of a nano-reinforced matrix of a polymer component with subsequent combination with bitumen. The claimed method allows to obtain a highly homogeneous polymer-bitumen binder material with close conditional viscosity at test temperatures of 25 and 0 ° C, as well as increased elasticity and extensibility at low temperatures, a wide range of ductility, low brittle temperature and high rates of cohesion, adhesion and stability properties. Moreover, the claimed method allows to reduce polymer consumption, the time of preparation of the mixture, and also simplifies its production.

The achievement of the specified technical result in part of the method for producing a polymer-bitumen binder material is ensured by the fact that the material is obtained by introducing a polymer component with stirring into bitumen, characterized in that prior to introduction into the bitumen, the polymer component is prepared. For its preparation, an SBS polymer of linear type 1.1-3.4 wt.% Is used, which is mixed with a previously prepared solution of SWCNTs - 0.001-0.03 wt.% And I-40A industrial oil - 2.2-9, 4 wt.% Dispersed to a homogeneous mass at a temperature of 100-120 ° C. Next, the polymer component is mixed with BND 60/90 bitumen - 87.2-96.7 wt.%, While the mixing process is carried out while maintaining the temperature of the mixture not more than 160 ° C, in particular, at a temperature of 120-160 ° C.

Claims (2)

1. A polymer-bitumen binder containing bitumen and a polymer component consisting of industrial oil and a polymer, characterized in that the polymer component contains a polymer of the thermoplastic elastomer class - block copolymer of butadiene and styrene of the SBS type - DST-30R-01, the solvent is plasticizer - industrial oil, nanomodified by single-walled carbon nanotubes (SWCNTs) without purification from impurities of carbon and metal nanoparticles, in the following ratio of components, wt.%:
DST-30R-01 1.1-3.4 industrial oil 2.2-9.4 SWCNT 0.001-0.03 bitumen rest. 2. A method of producing a polymer-bitumen binder according to claim 1, comprising introducing with stirring into the bitumen a polymer component, characterized in that prior to introducing into the bitumen, the polymer component is prepared by mixing SWCNTs with industrial oil at a temperature of 100-120 ° C and subsequent introduction polymer, after which the resulting mixture with stirring is introduced into bitumen at 120-160 ° C.

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