阅读说明：本技术 一种降低丁苯橡胶硫化胶生热的方法及其产品与制备方法 (Method for reducing heat generation of butadiene styrene rubber vulcanized rubber, product and preparation method thereof ) 是由 罗筑 季永春 田瑶珠 于 2020-06-09 设计创作，主要内容包括：本发明公开了一种降低丁苯橡胶生热的方法及其产品与制备方法。本发明通过对大麻纤维进行天然胶乳包覆,增强了纤维与丁苯橡胶基体间的粘结强度,限制了丁苯橡胶分子链的运动,降低了生热。而且本发明制备方法工艺简单,成本低廉,十分适宜工业化生产。(The invention discloses a method for reducing the heat generation of styrene butadiene rubber, a product and a preparation method thereof. According to the invention, the hemp fiber is coated with the natural latex, so that the bonding strength between the fiber and the styrene butadiene rubber matrix is enhanced, the movement of a styrene butadiene rubber molecular chain is limited, and the heat generation is reduced. The preparation method has simple process and low cost, and is very suitable for industrial production.)

1. A method for reducing heat generation of vulcanized styrene butadiene rubber is characterized by comprising the following steps: cleaning and drying hemp fibers, soaking the hemp fibers in an alkali solution, cleaning and drying the hemp fibers treated by the alkali solution, soaking and coating the hemp fibers with natural latex, drying the hemp fibers to obtain modified hemp fibers, and mixing the modified hemp fibers with styrene butadiene rubber to reduce the heat generation of the vulcanized styrene butadiene rubber.

2. The method of reducing heat generation of vulcanized styrene-butadiene rubber according to claim 1, wherein: the soaking treatment with the alkali solution refers to soaking for 20-60min with NaOH solution with the mass percentage concentration of 1-10%.

3. The method of reducing heat generation of vulcanized styrene-butadiene rubber according to claim 1, wherein: the soaking and coating by using the natural latex specifically means that the solid content of the natural latex is 20-60%, 20-200g of the natural latex is added into every 10g of hemp fiber, namely the solid-to-liquid ratio is 2-20; fully dispersing the hemp fibers in the added natural latex solution, completely immersing the hemp fibers in the natural latex, and drying to obtain the modified hemp fibers.

4. A rubber composite prepared from the modified hemp fiber obtained by the method of claim 1, 2 or 3, and vulcanized styrene-butadiene rubber and carbon black, wherein: the modified hemp fiber is prepared from 100 parts of styrene butadiene rubber, 20-60 parts of carbon black and 1.5-5 parts of modified hemp fiber in net fiber content by mass.

5. A method of preparing the composite material of claim 4, wherein: taking the components according to the mass parts, putting the styrene butadiene rubber, the carbon black and the modified hemp fiber into a 110-150 ℃ internal mixer for mixing for 5-8 minutes, then mixing on a 60-80 ℃ double-roll open mill, adding a sulfur vulcanization system and a compounding agent, and thinly passing for 3-5 times to obtain mixed rubber; and vulcanizing the mixed rubber according to the positive vulcanization time determined by a vulcanizer to prepare the modified hemp fiber reinforced vulcanized styrene-butadiene rubber composite material.

Technical Field

The invention relates to the field of polymer material science, in particular to a method for reducing heat generation of styrene butadiene rubber vulcanized rubber, a product and a preparation method thereof.

Background

With the continuous development of modern science and technology and the transportation industry, the speed of the automobile is accelerated continuously, the position and the function of the tire on the automobile are gradually improved, the internal temperature rise of the automobile tire is increased, and the requirements on the performance of the automobile tire are stricter. In addition, energy conservation and environmental protection are one of the main development directions of the automobile industry in the future.

Currently, there are 3 main forms of tire damage: mechanical damage, fatigue damage and thermal damage. In the loss of energy when the tire rolls, the heat loss of a car accounts for about 5 percent of the total energy loss, the heat loss of a truck accounts for about 10 percent, and especially the premature damage of the tire is often caused by the reduction of thermal oxidation and fatigue resistance caused by temperature rise. The styrene butadiene rubber has good wear resistance, good elasticity and convenient processing, is widely applied to automobile tires, but has high heat generation.

Disclosure of Invention

The invention provides a method for reducing heat generation of vulcanized styrene-butadiene rubber, a product and a preparation method thereof, and the heat generation of the obtained product is obviously reduced.

In order to achieve the purpose, the invention is realized by the following technical scheme: a method for reducing the heat generation of vulcanized butadiene styrene rubber includes such steps as washing hemp fibres, baking, immersing in alkali solution, washing, baking, immersing in natural latex, drying to obtain modified hemp fibres, and mixing with butadiene styrene rubber.

The soaking treatment with the alkali solution refers to soaking for 20-60min with NaOH solution with the mass percentage concentration of 1-10%.

The soaking and coating by using the natural latex specifically means that the solid content of the natural latex is 20-60%, 20-200g of the natural latex is added into every 10g of hemp fiber, namely the solid-to-liquid ratio is 2-20; fully dispersing the hemp fibers in the added natural latex solution, completely immersing the hemp fibers in the natural latex, and drying to obtain the modified hemp fibers.

The modified hemp fiber is prepared from 100 parts of styrene butadiene rubber, 20-60 parts of carbon black and 1.5-5 parts of modified hemp fiber in net fiber content by mass.

Taking the components according to the mass parts, putting the styrene butadiene rubber, the carbon black and the modified hemp fiber into a 110-150 ℃ internal mixer for mixing for 5-8 minutes, then mixing on a 60-80 ℃ double-roll open mill, adding a sulfur vulcanization system and a compounding agent, and thinly passing for 3-5 times to obtain mixed rubber; and vulcanizing the mixed rubber according to the positive vulcanization time determined by a vulcanizer to prepare the modified hemp fiber reinforced vulcanized styrene-butadiene rubber composite material.

The hemp fiber is derived from renewable resources, has the advantages of easily available raw materials, low pollution, high modulus and strength, light weight, low price and the like, is very suitable for being applied to the tire industry, and can replace part of carbon black as a reinforcing material to reduce heat generation. In hemp fibers, hemicellulose is a general term for non-cellulosic polysaccharides in hemp fibers, and complex polysaccharides with various numbers of chains or branched chains are often contained in the molecule, and thus, water absorption is easy. Lignin is an aromatic high polymer with a three-dimensional space network structure, has unstable performance, and is easy to condense when meeting the actions of acid, alkali, temperature, illumination and the like. The hemp fiber has better hydrophilicity and polarity, which can cause poor compatibility between the hemp fiber and a polymer matrix, so the invention can remove impurities such as hemicellulose, lignin, pectin, surface wax and the like after alkali treatment.

The natural rubber latex is a stable colloid dispersion system with natural rubber particles distributed in an aqueous medium, the main component of the natural rubber latex is rubber hydrocarbon, most of the natural rubber latex is cis-1, 4-polyisoprene, and the natural rubber latex has excellent properties of large elongation, small creep, low self-heating and the like. The inventor researches and discovers that the flexible interface layer is formed by coating the modified hemp fiber, the compatibility of the fiber and the matrix rubber is improved through co-vulcanization, the reinforcing effect of the fiber is improved, more importantly, the deformation shared by the flexible interface layer of the natural rubber is higher than that of the matrix rubber due to stress concentration generated by the larger difference of the modulus of the fiber and the modulus of the rubber under alternating strain, and the heat generation of the natural rubber is far less than that of the styrene-butadiene rubber, so that the heat generation of the styrene-butadiene rubber composite material is reduced.

According to the invention, the hemp fiber is coated with the natural latex, so that the bonding strength between the fiber and the styrene butadiene rubber matrix is enhanced, the movement of a styrene butadiene rubber molecular chain is limited, and the heat generation is reduced. The preparation method has simple process and low cost, and is very suitable for industrial production.

Detailed Description

The present invention is described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

Example 1 of the invention: cleaning and drying hemp fibers, soaking 4g of hemp fibers in a NaOH solution with the mass percentage concentration of 5% for 30min, cleaning and drying in a drying box, preparing a vulcanized styrene-butadiene rubber material by using the modified hemp fibers, styrene-butadiene rubber, carbon black and a compounding agent, and mixing the modified hemp fibers with styrene-butadiene rubber (Lanzhou petrochemical, 1500) and carbon black, wherein the styrene-butadiene rubber is 200g, the carbon black is 100g, and the net fiber content of the modified hemp fibers is 4 g; the materials are put into an internal mixer at 130 ℃ for mixing for 7 minutes, then are mixed on a two-roll open mill at 60 ℃, and 10g of zinc oxide, 8g of stearic acid, 3.92g of accelerator D1g, 4.42g of accelerator M, 3.92g of accelerator DM, 0.64g of accelerator TMTD, 3g of anti-aging agent SPC and 3.42g of sulfur are added. Performing thin-pass for 4-6 times to obtain rubber compound; and (3) vulcanizing the mixed rubber according to the positive vulcanization time tc90 measured by a rotor-free vulcanizer to prepare the hemp fiber reinforced vulcanized styrene-butadiene rubber composite material.

Example 2 of the invention: cleaning and drying hemp fibers, soaking 4g of hemp fibers in a 5% NaOH solution for 30min, cleaning, and drying in a drying oven to obtain alkali-treated hemp fibers. The mixture is soaked by natural rubber latex with solid content of 60%, and the solid-to-liquid ratio of hemp fiber to natural rubber latex is 1: and 5, drying by using an oven to obtain the modified hemp fiber. Preparing a vulcanized styrene-butadiene rubber material from modified hemp fibers, styrene-butadiene rubber, carbon black and a compounding agent, and mixing the modified hemp fibers, the styrene-butadiene rubber (Lanzhou petrochemical, 1500) and the carbon black, wherein the styrene-butadiene rubber is 200g, the carbon black is 100g, and the net fiber content of the modified hemp fibers is 4 g; the materials are put into an internal mixer at 130 ℃ for mixing for 7 minutes, then are mixed on a two-roll open mill at 60 ℃, and 10g of zinc oxide, 8g of stearic acid, 3.92g of accelerator D1g, 4.42g of accelerator M, 3.92g of accelerator DM, 0.64g of accelerator TMTD, 3g of anti-aging agent SPC and 3.42g of sulfur are added. Performing thin-pass for 4-6 times to obtain rubber compound; and vulcanizing the mixed rubber according to the positive vulcanization time tc90 measured by a rotor-free vulcanizer to prepare the hemp fiber reinforced vulcanized natural rubber composite material.

Example 3 of the invention: a modification method of hemp fiber comprises cleaning hemp fiber, oven drying, soaking 8g hemp fiber in 8% NaOH solution for 15min, cleaning, oven drying; infiltrating with a natural latex solution with the solid content of 20%, wherein the solid-to-liquid ratio of the hemp fibers to the natural latex is 1: and 10, drying by using an oven to obtain the modified hemp fiber. Mixing the modified hemp fiber with styrene butadiene rubber (Lanzhou petrochemical, 1500) and carbon black, wherein the styrene butadiene rubber is 200g, the carbon black is 100g, and the net fiber content of the modified hemp fiber is 8 g; the materials are put into an internal mixer at 130 ℃ for mixing for 7 minutes, then are mixed on a two-roll open mill at 60 ℃, and 10g of zinc oxide, 8g of stearic acid, 3.92g of accelerator D1g, 4.42g of accelerator M, 3.92g of accelerator DM, 0.64g of accelerator TMTD, 3g of anti-aging agent SPC and 3.42g of sulfur are added. Performing thin-pass for 4-6 times to obtain rubber compound; and (3) vulcanizing the mixed rubber according to the positive vulcanization time tc90 measured by a rotor-free vulcanizer to prepare the modified hemp fiber reinforced vulcanized natural rubber composite material.

Preparation of blank control: styrene butadiene rubber (Lanzhou petrochemical, 1500) is 200g, and carbon black is 100 g; the mixed materials are put into an internal mixer at 130 ℃ for mixing for 7 minutes, then are mixed on a two-roll open mill at 60 ℃, and are added with 10g of zinc oxide, 8g of stearic acid, 3.92g of accelerator D1g, 4.42g of accelerator M, 3.92g of accelerator DM, 0.64g of accelerator TMTD, 3g of anti-aging agent SPC and 3.42g of sulfur. Performing thin-pass for 4-6 times to obtain rubber compound; and (3) vulcanizing the mixed rubber according to the positive vulcanization time tc90 measured by a rotor-free vulcanizer to prepare the styrene-butadiene rubber composite material.

The heat buildup test results of the vulcanized natural rubber composite materials of different experimental schemes are shown in the table 1(GB 1687-93).

TABLE 1 Heat buildup Performance results for the cured composites

From the test results, the hemp fibers not coated with the natural latex had no effect of reducing the heat generation, and the hemp fibers coated with the natural latex had an effect of significantly reducing the heat generation. The modified hemp fiber prepared by the patent process method is applied to styrene butadiene rubber/carbon black, so that the heat generation can be obviously reduced, and the effectiveness of the patent method is reflected.