Mineral composite that activates photooxidation of thermoplastics
Patent Information
- Authority / Receiving Office
- RU · RU
- Patent Type
- Patents
- Current Assignee / Owner
- FEDERAL STATE BUDGETARY EDUCATIONAL INSTITUTION OF HIGHER EDUCATION PLEKHANOV RUSSIAN UNIV OF ECONOMICS
- Filing Date
- 2025-03-03
- Publication Date
- 2026-07-02
AI Technical Summary
Existing polymer compositions lack effective oxidative degradation mechanisms that ensure biodegradability without compromising mechanical properties and environmental safety, particularly due to the limitations of variable valence metal stearates, absence of metals in photodegradable compositions, and labor-intensive production methods.
A mineral composition is produced using metals of variable valence, specifically calcium compounds modified with potassium permanganate, mixed with a polymer matrix to enhance oxidative degradation through photoinitiation, involving ultrasonic mixing and calcination.
The method accelerates polymer photooxidation, leading to materials that degrade while maintaining initial strength and stability, with improved mechanical properties and environmental safety.
Abstract
Description
[0001] Field of technology to which the invention relates (field of application of the invention):
[0002] The invention consists of a method for producing and formulating a mineral composition containing transition metal-based additives that enhance the oxidative degradation of polymers upon photoinitiation. The composition can be used to produce various oxo-degradable materials, such as films for packaging building materials, wood-filled profile products for construction and finishing, garden tools and materials, agricultural films, etc. A distinctive feature of the invention is the ability to create materials that, under normal use conditions, retain the necessary strength and stability, but degrade upon release into nature without harming the environment. The present invention is an oxo-degradable additive based on transition metals.
[0003] Prior art information:
[0004] A known method (Patent CA 2821357 A1) for producing a composite additive that does not contain natural components and imparts biodegradability to polyolefin materials after the end of their useful life. The additive comprises a prooxidant (15-30 wt.%), which is one or more metal stearates selected from the group consisting of manganese, iron and cobalt, one or more phenolic antioxidants (10-20 wt.%), a filler - calcium carbonate and / or titanium dioxide and a polymer base (polyethylene or polypropylene). The additive is introduced into the base polymer in an amount of 1-5 wt.%. A disadvantage of this method is the use of only variable valence metal stearates, which narrows the scope of application of the invention.
[0005] A light-degradable polymer composition (JP Patent 2007177083) is known, containing a mixture of polyethylene and polypropylene, and as additives 40-65% by weight of calcium carbonate, 3-5% by weight of stearin, and 1-3% by weight of stearic acid. A disadvantage is the absence of metals of variable valence, the most highly effective prooxidants, in the composition.
[0006] A photodegradable composition based on polyolefins (high- or low-density polyethylene, polypropylene, copolymers of ethylene with propylene, higher olefins, vinyl acetate, etc.) is known, containing alkyloxysilylferrocene as a photosensitizing additive (Patent RU 94023952). A disadvantage is the presence of a ferrocene derivative in the composition, which limits the use of the composition due to the impossibility of producing materials that come into contact with humans.
[0007] The closest to the claimed technical solution is the method (Patent RU 2717032C1) for producing elastomeric compositions with a high content of mineral filler. The technical result of this invention is the production of an organo-mineral composite that promotes the biodegradation of thermoplastics. The method for producing the composite includes the stages of preparing an aqueous dispersion of a mineral modified filler of the composition, wt.%: water - 92.92 - 92.96; natural calcium carbonate - 7.00 and PolyDADMAC 0.04 - 0.08 (carried out by mixing the components under ultrasonic exposure from 2.0 to 6.0 min), liquid-phase combination of an aqueous dispersion of filler with latex (carried out by dilution to a rubber content of dry matter from 5.0 to 15.0 wt.%, after which an aqueous dispersion of calcium carbonate is introduced at the following ratio of components, parts by weight.Natural rubber: modified calcium carbonate (100:(250÷400)), isolation of the filled elastomer system, dehydration, and drying of the resulting composite. The disadvantages of this technical solution are the labor-intensive nature of the composition production, as well as the comparatively low relative elongation and tensile strength, compared to those of the present invention.
[0008] Disclosure of the essence of the invention (information disclosing the technical result and the essence of the invention as a technical solution, essential features of the invention):
[0009] The aim of the present invention is to create a mineral composition that promotes oxidative degradation of polyolefin thermoplastics during photoinitiation.
[0010] The set objective is achieved by the method for producing an oxo-degradable additive using metals of variable valence based on the modification of calcium compounds with potassium permanganate to obtain a homogeneous powder and its further mixing into a polymer matrix of polyolefins on mixing rollers in a ratio of wt. %: solvent water or acetone - from 81.0 to 84.4; calcium compound - from 15.2 to 18.5 and potassium permanganate from 0.4 to 0.5. Mixing of the solvent water or acetone and potassium permanganate is carried out using an ultrasonic disperser at a rotation speed of 3000 rpm for 5 minutes, further preparation of a solution with a calcium compound is carried out using an ultrasonic disperser at a rotation speed of 5000 rpm for 20 minutes at a room temperature of 25 ° C. After mixing, the resulting solution is dried at 60°C, then calcined at 900°C. The resulting mixture is ground in a mortar.
[0011] The technical result of the invention consists in obtaining a mineral composite that promotes the acceleration of the polymer photooxidation process, as a result of which the material loses its strength properties.
[0012] The proposed method for producing a composite that promotes the oxodecomposition of thermoplastics uses:
[0013] Table 1 – Chemical composition of oxo-degradable additive
[0014] Parameters Meaning Calcium carbonate, % (wt.) 15,2 - 18,5 Acetone, % (mass) 81,0 Calcium oxide, % (wt.) 15,2 - 18,5 Potassium permanganate,% (wt.) 0,4 - 0,5 Water, % (mass) 84,4
[0015] The method for producing a composite using metals of variable valence for the oxodecomposition of thermoplastics is carried out as follows:
[0016] Prepare a potassium permanganate solution in a 100 ml container. Add 50 g or 39.5 g of water or acetone solvent, respectively, and add potassium permanganate. The resulting solution is then thoroughly mixed with an ultrasonic disperser at 3000 rpm for 5 minutes. Next, pour the potassium permanganate solution into a beaker containing 9 g of the carrier. The resulting solution is mixed with an ultrasonic disperser at 5000 rpm for 20 minutes at room temperature (25°C). After mixing, the resulting solution is dried at 60°C and then calcined at 900°C if necessary. The resulting mixture is ground in a mortar.
[0017] The method is characterized by the following application examples. To evaluate the oxodegradability of polymer composites, the additive was mixed into the polymer using mixing rollers in a ratio of 95 to 99% by weight of polymer and 1 to 5% by weight of filler to produce a homogeneous mass, from which films 40 µm thick were subsequently produced.
[0018] Example #1
[0019] A solution of potassium permanganate is prepared in a container using acetone as the solvent. 39.5 g of acetone is poured into it, 0.25 g of potassium permanganate is added. The resulting solution is then thoroughly mixed with an ultrasonic disperser at a speed of 3000 rpm for 5 minutes. Next, the potassium permanganate solution is poured into a beaker with 9 g of CaCO3. The resulting solution is mixed with an ultrasonic disperser at a speed of 5000 rpm for 20 minutes at a room temperature of 25°C. After mixing, the resulting solution was dried at 60°C, then calcined at 900°C. The resulting mixture was ground in a mortar. To assess the oxo-degradability of polymer composites, the additive was mixed into the polymer in a ratio of 99 to 1 wt.%, respectively, using mixing rollers. The results are presented in Table 2 (No. 1,2).
[0020] Example #2
[0021] The process was carried out similarly to example No. 1, but 9 g of CaO was added as a carrier. The results are presented in Table 2 (Nos. 3, 4).
[0022] Example #3
[0023] The process was carried out similarly to example No. 2, however, 1 g of KMnO4 was used in the initial solution instead of 0.25 g, and 50 g of water was used as a solvent. The results are presented in Table 2 (No. 5,6).
[0024] Example #4
[0025] The process was carried out similarly to example No. 1, however, water was used as a solvent, and the polymer-to-filler ratio was 97-3 wt.%. The results are presented in Table 3 (No. 1, 2).
[0026] Example #5
[0027] The process was carried out similarly to example No. 2, however, water was used as a solvent, and the polymer-to-filler ratio was 97-3 wt.%. The results are presented in Table 3 (No. 3,4).
[0028] Example #6
[0029] The process was carried out similarly to example No. 3, however, the polymer-to-filler ratio was 97-3 wt.%. The results are presented in Table 3 (No. 5,6).
[0030] Example #7
[0031] The process was carried out similarly to example No. 1, however, water was used as a solvent, and the polymer-to-filler ratio was 95-5 wt.%. The results are presented in Table 4 (No. 1, 2).
[0032] Example #8
[0033] The process was carried out similarly to example No. 2, however, water was used as a solvent, and the polymer-to-filler ratio was 95-5 wt.%. The results are presented in Table 4 (No. 3,4).
[0034] Example #9
[0035] The process was carried out similarly to example No. 3, however, the polymer-to-filler ratio was 95-5 wt.%. The results are presented in Table 4 (No. 5,6).
[0036] Table 2. Results of mechanical tensile tests of films containing an oxo-degradable additive in the ratio of wt.%: polymer - 99; filler 1
[0037] № Relative elongation at break, % Tensile strength, MPa Before irradiation After 150 hours of irradiation Before irradiation After 150 hours of irradiation 1 254 150 10,3 7 2 259 153 10,5 7,1 3 394 190 10,0 6,8 4 294 164 10,7 7,2 5 345 175 10,0 6,7 6 278 168 10,2 6,9
[0038] Table 3. Results of mechanical tensile tests of films containing an oxo-degradable additive in the ratio of wt.%: polymer - 97; filler 3
[0039] № Relative elongation at break, % Tensile strength, MPa Before irradiation After 150 hours of irradiation Before irradiation After 150 hours of irradiation 1 202 115 9,7 6,6 2 186 110 10,1 7,0 3 316 147 9,7 6,6 4 225 129 10,4 7,0 5 275 128 9,8 6,6 6 214 112 9,8 6,5
[0040] Table 4. Results of mechanical tensile tests of films containing an oxo-degradable additive in the ratio of wt.%: polymer - 95; filler 5
[0041] № Relative elongation at break, % Tensile strength, MPa Before irradiation After 150 hours of irradiation Before irradiation After 150 hours of irradiation 1 128 58 9,5 6,4 2 125 56 9,7 6,6 3 264 91 9,4 6,4 4 159 71 10,2 6,9 5 212 77 9,6 6,5 6 152 72 9,7 6,6
[0042] As can be seen from Tables 2-4, the use of oxo-degradable additives based on metals of variable valence promotes the initiation of oxo-degradation processes, which causes a significant decrease in the relative strength and relative elongation, and also allows films containing the declared additive to be given the ability to accelerated oxo-degradation, while in compositions containing CaO, obtained according to Example No. 2, they have the best initial values of the physical and mechanical properties of the resulting products.