A method for reactive extrusion copolymerization of vinyl monomers

Abstract

A method for reactive extrusion copolymerization of vinyl monomers is to feed vinyl monomers or at least one vinyl comonomer and an initiator into the first screw section of a twin-screw extruder, and in the following Add modified resin in the screw section; continue to add corresponding monomers in the screw section after the system enters the automatic acceleration zone, and continue to add the initiator corresponding to the temperature of the screw barrel after the half-life of the initiator, as well as the micro-nano resin used for modification. Inorganic modified materials; and when the polymerization is terminated, antioxidants and anti-ultraviolet agents are added, and then unpolymerized monomers and by-products are removed through the devolatilization screw segment; by controlling the temperature of different screw segments, the reaction extrusion polymerization obtains a predetermined Vinyl copolymer resin with a molecular weight of 5×102 to 6×105. The invention overcomes the defects existing in the existing free radical reaction extrusion polymerization technology, can fully meet the requirement of short residence time of reaction extrusion polymerization, integrates functionalization and high performance, and at the same time can meet the requirements of polymers to achieve high molecular weight requirements.

Description

technical field

[0001] The invention relates to a polymerization method of a copolymer, in particular to a method for reactive extrusion copolymerization of vinyl monomers. Background technique

[0002] Polymers of vinyl monomers are usually called vinyl polymers, and their polymerization has become an extremely important part of high polymer synthesis. For example, polystyrene, polyvinyl chloride, poly(meth)acrylate, polyvinyl acetate, ABS resin, and related and widely used plastics, rubber, thermoplastic elastomers, coatings, etc. Monomer synthesis, most of which are obtained by free radical polymerization, accounts for almost half of the polymer. However, due to the fast polymerization reaction speed of this type of polymer, the large heat release, and the rapid increase in the viscosity of the material, it is difficult to remove the heat of reaction and the diffusion and uniform distribution of monomers, making it difficult to implement this type of polymer in bulk. po...

Examples

Embodiment 1

[0047] Methyl methacrylate (MMA) was selected as the vinyl monomer, maleic anhydride (MAH) was selected as the vinyl comonomer, and the mass ratio of the two was 95.2:4.8. reactivity ratio r MMA and r MAH They are 6.7 and 0.02 respectively, indicating that MMA is more likely to self-polymerize, while MAH tends to be copolymerized, which is obviously not conducive to the appearance of MAH on the copolymer molecular chain, so it is necessary to strengthen the content of MAH raw materials at the initial stage of polymerization. MAH is dissolved in MMA, the mass ratio of the two is 88.9:11.1, and the benzoyl peroxide (BPO) of the two total amount 0.93% mass fraction is added therein, then with the metering of 1.54kg / h Speed, using a diaphragm pump with an ultimate pressure of 15MPa to input a Ф35, length-to-diameter ratio: L / D=60, such as figure 1 In the reverse flow structure shown, the first screw section of the co-rotating tightly intermeshing twin-screw extruder, the tempera...

Embodiment 2

[0054] Styrene (St) was selected as the vinyl monomer, and maleic anhydride (MAH) was selected as the vinyl comonomer, and the mass ratio of the two was 97.09:2.91. Since the reactivity ratio of the two belongs to the ideal alternating copolymerization, the component ratio of the copolymer is the same as the raw material ratio, so there is no need to consider strengthening the raw material to strengthen the reaction in advance. Then choose styrene-butadiene-styrene triblock thermoplastic elastomer (SBS), molecular weight is 1.5×10 5 , dissolved in the above two mixed monomers, the mass ratio of mixed monomers to SBS is 7.5:2.5. Azobisisobutyronitrile is selected as the initiator, and the addition amount is 1.2% by mass fraction of the total amount of the two mixed monomers. Then, with a metering rate of 3.6kg / h, a diaphragm pump with an ultimate pressure of 15MPa is used to input a twin-screw power inlet with a pressure resistance of 1MPa and no leakage Ф35, the length-to-dia...

Embodiment 3

[0060] Styrene (St) was selected as the vinyl monomer, acrylonitrile (AN) and glycidyl methacrylate (GMA) were selected as the vinyl comonomer, and the mass ratio of the three was 69.9:30:0.1. Since the reactivity ratios of AN, GMA and St are all less than 1, the component ratio of the copolymer can be regarded as the same as the raw material ratio, so there is no need to consider strengthening the raw material to strengthen the reaction in advance.

[0061] The three of St, AN and GMA are evenly mixed together, and the benzoyl peroxide (BPO) of the three total amount 0.80% mass fraction is added therein, then with the metering rate of 1.54kg / h, the ultimate pressure is 15MPa diaphragm pump input a Ф40, aspect ratio: L / D = 65, such as figure 1 Shown is the first screw section of the co-rotating tight-meshing twin-screw extruder with reverse flow structure, and the temperature of the screw barrel is set at 70-110°C according to the requirements of the polymer molecular weight. ...

technical field

[0001] The invention relates to a polymerization method of a copolymer, in particular to a method for reactive extrusion copolymerization of vinyl monomers. Background technique

[0002] Polymers of vinyl monomers are usually called vinyl polymers, and their polymerization has become an extremely important part of high polymer synthesis. For example, polystyrene, polyvinyl chloride, poly(meth)acrylate, polyvinyl acetate, ABS resin, and related and widely used plastics, rubber, thermoplastic elastomers, coatings, etc. Monomer synthesis, most of which are obtained by free radical polymerization, accounts for almost half of the polymer. However, due to the fast polymerization reaction speed of this type of polymer, the large heat release, and the rapid increase in the viscosity of the material, it is difficult to remove the heat of reaction and the diffusion and uniform distribution of monomers, making it difficult to implement this type of polymer in bulk. po...

Examples

Embodiment 1

[0047] Methyl methacrylate (MMA) was selected as the vinyl monomer, maleic anhydride (MAH) was selected as the vinyl comonomer, and the mass ratio of the two was 95.2:4.8. reactivity ratio r MMA and r MAH They are 6.7 and 0.02 respectively, indicating that MMA is more likely to self-polymerize, while MAH tends to be copolymerized, which is obviously not conducive to the appearance of MAH on the copolymer molecular chain, so it is necessary to strengthen the content of MAH raw materials at the initial stage of polymerization. MAH is dissolved in MMA, the mass ratio of the two is 88.9:11.1, and the benzoyl peroxide (BPO) of the two total amount 0.93% mass fraction is added therein, then with the metering of 1.54kg / h Speed, using a diaphragm pump with an ultimate pressure of 15MPa to input a Ф35, length-to-diameter ratio: L / D=60, such as figure 1 In the reverse flow structure shown, the first screw section of the co-rotating tightly intermeshing twin-screw extruder, the tempera...

Embodiment 2

[0054] Styrene (St) was selected as the vinyl monomer, and maleic anhydride (MAH) was selected as the vinyl comonomer, and the mass ratio of the two was 97.09:2.91. Since the reactivity ratio of the two belongs to the ideal alternating copolymerization, the component ratio of the copolymer is the same as the raw material ratio, so there is no need to consider strengthening the raw material to strengthen the reaction in advance. Then choose styrene-butadiene-styrene triblock thermoplastic elastomer (SBS), molecular weight is 1.5×10 5 , dissolved in the above two mixed monomers, the mass ratio of mixed monomers to SBS is 7.5:2.5. Azobisisobutyronitrile is selected as the initiator, and the addition amount is 1.2% by mass fraction of the total amount of the two mixed monomers. Then, with a metering rate of 3.6kg / h, a diaphragm pump with an ultimate pressure of 15MPa is used to input a twin-screw power inlet with a pressure resistance of 1MPa and no leakage Ф35, the length-to-dia...

Embodiment 3

[0060] Styrene (St) was selected as the vinyl monomer, acrylonitrile (AN) and glycidyl methacrylate (GMA) were selected as the vinyl comonomer, and the mass ratio of the three was 69.9:30:0.1. Since the reactivity ratios of AN, GMA and St are all less than 1, the component ratio of the copolymer can be regarded as the same as the raw material ratio, so there is no need to consider strengthening the raw material to strengthen the reaction in advance.

[0061] The three of St, AN and GMA are evenly mixed together, and the benzoyl peroxide (BPO) of the three total amount 0.80% mass fraction is added therein, then with the metering rate of 1.54kg / h, the ultimate pressure is 15MPa diaphragm pump input a Ф40, aspect ratio: L / D = 65, such as figure 1 Shown is the first screw section of the co-rotating tight-meshing twin-screw extruder with reverse flow structure, and the temperature of the screw barrel is set at 70-110°C according to the requirements of the polymer molecular weight. ...

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