CN111303551A - A kind of vinyl chloride resin composite and preparation method thereof - Google Patents

Abstract

The invention belongs to the field of polymer materials, and discloses a vinyl chloride resin compound and a preparation method thereof. The preparation method of the vinyl chloride resin compound comprises: performing a heterogeneous polymerization reaction of solid vinyl chloride resin with isobutylene or with a mixture of isobutylene and other comonomers in the presence of a co-initiator and an electron donor. The vinyl chloride resin composite that can be prepared in situ by the method provided by the present invention, wherein the two-phase dispersion of vinyl chloride resin and isobutylene-based polymer segments is uniform, and improved mechanical properties, plasticizing properties, thermal stability and gas performance are obtained. A new type of vinyl chloride resin-based composite material with excellent comprehensive properties, which is integrated with tightness, has a simple production process and saves production costs.

Description

A kind of vinyl chloride resin composite and preparation method thereof

technical field

The invention belongs to the field of polymer materials, and more particularly, relates to a vinyl chloride resin compound and a preparation method thereof.

Background technique

Vinyl chloride resin is a general term for polymers obtained by polymerizing vinyl chloride to obtain polyvinyl chloride or vinyl chloride as the main copolymer and one or more other unsaturated compounds. Polyvinyl chloride (PVC) is one of the top five general-purpose resins in the world. It has excellent overall cost-effectiveness. Its outstanding advantages are flame retardancy, good transparency, chemical corrosion resistance and wear resistance. It is widely used in pipes, window frames, floors, wallpapers, etc. , curtains, cables and wires, coatings, packaging materials, medical pipes, blood bags and imitation leather, etc., but its thermal stability, toughness, impact strength and processing performance are still insufficient, which restricts its high performance requirements. The development and application of the field (see: Cui Mingsheng, Zhang Ping, He Shengxi, Research Progress and Prospects of Polyvinyl Chloride Modification, China Chlor-Alkali, 2017(05): 11-14). Chlorinated polyvinyl chloride is the product of further chlorination of polyvinyl chloride and is a modified product of polyvinyl chloride.

Taking PVC as an example, its melting temperature is high, and its melt viscosity is very large, so it is difficult to process such as injection molding. The plasticizing modification effect can be achieved by adding plasticizers to PVC. Among them, phthalates are The most widely used type of PVC plasticizer, but the migration of small molecular plasticizers is harmful to the environment and human health. Currently, European and American countries have restricted phthalates in the fields of clothing packaging, medical supplies and children's toys. application of plasticizers. The introduction of large steric hindrance or functional side groups on the molecular chain through graft modification, such as bonding diisooctyl phthalate on the main chain of PVC, can effectively eliminate the migration problem of plasticizers, and the internal increase Good plasticization (see: Navarro R, Perrino M P, Tardajos M G, Reinecke H, Phthalate Plasticizers Covalently Bound to PVC: Plasticization with suppressed migration, Macromolecules, 2010, 43: 2377-2381). Copolymerization of vinyl chloride monomer and second monomer (such as vinyl acetate, ethyl acrylate, etc.) can reduce the glass transition temperature of PVC-based materials and achieve a plasticizing effect, but the inner plasticized PVC material obtained by this method has The mechanical properties will be greatly reduced and cannot meet the needs of use. Introducing large sterically hindered groups into PVC side groups can also achieve internal plasticization. For example, grafting hyperbranched polyglycerol ester (HPG) to the main chain of PVC can greatly reduce the intermolecular force, and the plasticizing effect is obvious. The synthesis process is complicated, and at the same time, due to the low thermal decomposition temperature of branched HPG, it will further impair the thermal stability of PVC (see: Kyu Won Lee, Jae Woo Chung, Seung-Yeop Kwak, Structurally Enhanced Self-Plasticization of Poly(vinyl chloride) via Click Grafting of Hyperbranched Polyglycerol, Macromol. Rapid Commun., 2016, 37:2045-2051).

Rigid PVC has poor toughness (especially low temperature toughness), and it is physically combined with elastomer toughening agents (such as nitrile rubber, chlorinated polyethylene, acrylonitrile-butadiene-styrene copolymer, acrylonitrile -Butadiene-styrene copolymer, etc.) or rigid particles (such as polymethyl methacrylate, polystyrene, nano-silica, nano-calcium carbonate, etc.) blending and compounding can improve the toughness of PVC (see: Shokri AA , Bakhshandeh GR, Farahani T D. An investigation of mechanical and rheological properties of NBR/PVC blends: influence of anhydride additives, mixing procedure and NBR form. Iranian Polymer Journal, 2006, 15(15): 227; Zhou Liling, Wang Xin, Lin Yusheng, Yang Jingyi, Wu Qiye, Structure and Properties of Two Blending Systems of PVC/ABS and PVC/CPE, Journal of Qingdao University of Science and Technology (Natural Science Edition), 2003, (01): 48-52). However, the incompatibility of the system will lead to uneven distribution of the toughening agent, which will seriously affect the performance of the material. Therefore, a certain surface treatment of the toughening agent is required before blending and modification, and the process is relatively complicated (see: Chen Shaohui, Song Yihu , Du Peihua, Zhu Xiaonan, Zheng Qiang, Mechanical properties of PVC/CPE/CaCO3 composites, Chinese Journal _of Materials Science and Engineering, 2011, 29(06): 829-832, 845).

Polyisobutylene (PIB) is a polymer obtained by cationic (positive) ion polymerization of isobutylene. It has excellent air tightness, water tightness, aging resistance, electrical insulation, heat resistance, cold resistance, dielectric properties, etc. characteristic. Isobutylene can be copolymerized with cationically polymerizable monomers (such as conjugated dienes or vinyl aromatics), such as isobutylene and a small amount of isoprene to prepare butyl rubber, and isobutylene to copolymerize with a small amount of p-methylstyrene to prepare isobutylene-based specialties Elastomer. Through physical blending of PIB and PVC, although the defects of PVC material can be improved to a certain extent, and its toughness and mechanical damping performance can be improved, but the blending compatibility of the two is poor, and it is difficult to mix uniformly. When the amount of PIB exceeds 20wt%, The properties of the blends are greatly reduced (see: Fan Shixia, Zhang Fenyu, Qiu Lingwei, Zhang Qingyu, Damping Properties of Polyvinyl Chloride-Low Molecular Weight Polyisobutylene Blends, Applied Chemistry, 1990, 7(3): 51-53).

In the prior art, if the cationic polymerization of isobutylene is initiated by PVC, there are problems of extremely low grafting efficiency and low grafting amount, and a large amount of Lewis acid is usually used as a co-initiator and introduced into the polymerization system during the preparation process. Expensive proton scavengers, such as 2,6-di-tert-butylpyridine (DtBP, about 400 yuan/g), are not easy to be removed in the post-treatment process, which increases the difficulty of the process and increases the production cost (see: Kennedy J P , Graft Modification of Poly(viny1Chloride) and Related Reactions, Journal of Applied Polymer Science, 1972, 10: 2507-2525); Pi Z, Kennedy J P, Cationic Grafting of Olefins from PVC: The Effect of Reaction Conditions, Journal of Applied Polymer Science , 2001, 39:1675-1680).

In summary, PVC materials have the problems of poor thermal stability, poor toughness, low impact strength and poor processing performance. Although they can be modified by traditional physical blending methods, they also have poor compatibility and small There are many problems such as molecular migration and unstable material properties; although thermal stability, plasticity or toughness can be improved by chemical methods, other properties will be sacrificed at the same time, and there are problems such as high preparation cost, complex process and limitations.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a new vinyl chloride resin compound and a preparation method thereof in order to overcome the above defects of the prior art.

Specifically, the present invention provides a vinyl chloride resin compound, wherein the vinyl chloride resin compound comprises a solid vinyl chloride resin solid and a vinyl chloride resin graft copolymer coated on the surface of the vinyl chloride resin solid, The vinyl chloride resin is selected from at least one of polyvinyl chloride, chlorinated polyvinyl chloride, and vinyl chloride and vinyl acetate copolymers, and the vinyl chloride resin graft copolymer is made of polyvinyl chloride, chlorinated polyvinyl chloride, and polyvinyl chloride. A polymer in which ethylene or vinyl chloride and vinyl acetate copolymer is used as the main chain and a plurality of isobutylene-based polymer segment branches are connected on the main chain, based on the total mass of the vinyl chloride resin compound, the isobutylene The total mass content of the branched chain of the base polymer segment is 5-50 wt%.

The present invention also provides a method for preparing a vinyl chloride resin compound, the method comprising: mixing solid vinyl chloride resin with isobutylene or with isobutylene and other comonomers in the presence of a co-initiator and an electron donor. Heterogeneous polymerization.

The present invention also provides the vinyl chloride resin composite prepared by the above method.

The vinyl chloride resin compound can be prepared in situ by the method provided by the invention, wherein the two-phase dispersion of the vinyl chloride resin and the isobutylene-based polymer segment is uniform, and improved mechanical properties, plasticizing properties, thermal stability and air tightness are obtained. A new type of vinyl chloride resin compound with excellent comprehensive properties in one, and the production process is simple, which saves the production cost. The vinyl chloride resin composite has excellent mechanical properties, the tensile strength can be as high as 46MPa, and the elongation at break can be as high as 45%. Compared with the corresponding vinyl chloride resin, the effect of strengthening and toughening is achieved; the vinyl chloride resin The resin composite has better processability and improved thermal stability, its decomposition temperature is up to 44°C higher than that of the corresponding vinyl chloride resin, and the processing window is widened; the vinyl chloride resin composite also has excellent gas barrier The performance is up to 20 times higher than the corresponding vinyl chloride resin.

Other features and advantages of the present invention will be described in detail in the detailed description that follows.

Description of drawings

The above and other objects, features and advantages of the present invention will become more apparent from the more detailed description of the exemplary embodiments of the present invention in conjunction with the accompanying drawings.

FIG. 1 shows a schematic diagram of the tensile strength comparison between the PVC/PVC-g-PIB composite prepared in Example 2 of the present invention and the PVC in Comparative Example 1. FIG.

Detailed ways

Preferred embodiments of the present invention will be described in more detail below. While the preferred embodiments of the present invention are described below, it should be understood that the present invention may be embodied in various forms and should not be limited by the embodiments set forth herein.

The vinyl chloride resin composite provided by the present invention includes solid vinyl chloride resin and vinyl chloride resin graft copolymer coated on the surface of the vinyl chloride resin, and the vinyl chloride resin is selected from polyvinyl chloride, chlorinated polyvinyl chloride and at least one of vinyl chloride and vinyl acetate copolymers, the vinyl chloride resin graft copolymers are polyvinyl chloride, chlorinated polyvinyl chloride or vinyl chloride and vinyl acetate copolymers as the main chain and in the A polymer with a plurality of branched chains of isobutylene-based polymer segments connected to the main chain, based on the total mass of the vinyl chloride resin composite, the total mass content of the branched chains of the isobutylene-based polymer segments is 5-50 wt%, preferably 7-45 wt%, more preferably 9-40%.

The branched chain of the isobutene-based polymer segment can be a homopolymeric segment of isobutene, or a copolymerized segment of isobutene and other comonomers. Wherein, when the branched chain of the isobutene-based polymer segment is a copolymerized segment of isobutene and other comonomers, the molar content of the isobutene structural unit may be 95.0-99.9 mol%. Said other comonomers are preferably conjugated dienes and/or vinyl aromatics. Specific examples of the conjugated diene include, but are not limited to, at least one of 1,3-butadiene, 1,3-pentadiene, and isoprene. Specific examples of the vinyl aromatic hydrocarbons include, but are not limited to: styrene, p-methylstyrene, alpha-methylstyrene, p-methoxystyrene, p-chloromethylstyrene, p-tert-butylstyrene and At least one of p-tert-butoxystyrene.

The polymer weight-average molecular weight ( _Mw ) of the vinyl chloride resin is preferably 50-400kg/mol, more preferably 60-380kg/mol, most preferably 70-350kg/mol; molecular weight distribution index _Mw / _Mn is preferably is 1.3-4.0, more preferably 1.4-3.5, most preferably 1.5-3.2.

The vinyl chloride resin is the product of vinyl chloride through suspension polymerization, emulsion polymerization or bulk polymerization, preferably in granular or powder form, and its particle size is preferably 0.1 μm or more, more preferably 0.2-500 μm, further preferably 2-400 μm , most preferably 5-370 μm. The vinyl chloride resin particles or powder may have a broad particle size distribution, and may be of a dense structure type or a loose structure type. The vinyl chloride resin has a small particle size or a loose structure, and its specific surface area is large, which is conducive to grafting more isobutylene-based polymer segments.

The preparation method of the vinyl chloride resin compound provided by the present invention comprises: performing a heterogeneous polymerization reaction of a solid vinyl chloride resin with isobutylene or a mixture of isobutylene and other comonomers in the presence of a co-initiator and an electron donor. Here, the term "heterogeneous polymerization" refers to a polymerization reaction carried out in a heterogeneous system.

The present invention has no particular limitation on the order of adding each raw material before the heterogeneous polymerization reaction. According to a preferred embodiment of the present invention, the method for the heterogeneous polymerization comprises:

A. The solid vinyl chloride resin is mixed with other comonomers containing isobutylene and optionally to form a heterogeneous system, and the heterogeneous system contains or does not contain a reaction medium, and the reaction medium is an organic solvent or water A phase medium or an organic solvent and an aqueous phase medium at the same time, the organic solvent is an inert liquid organic substance that does not dissolve the solid vinyl chloride resin but can disperse or swell it;

B. The reaction system formed in step A is mixed with a co-initiator and an electron donor to initiate a heterogeneous polymerization reaction.

According to the present invention, the molar ratio of the polyvinyl chloride, co-initiator, electron donor and isobutylene may be (1.2×10 ^-3 -6.0×10 ^-3 ): (5.0×10 ^-3 -8.0×10 ^-2 ): (6.0×10 ⁻⁴ −8.0×10 ⁻² ): 1, preferably (1.4×10 ⁻³ −5.5×10 ⁻³ ): (5.5×10 ⁻³ −7.5×10 ⁻² ): (6.5 ×10 ^-4 -7.0 × 10 ^-2 ): 1, more preferably (1.8 × 10 ^-3 -5.0 × 10 ^-3 ): (6.0 × 10 ^-3 -7.0 × 10 ^-2 ): (7.0 × 10 ^{- 4-6.0} × ^10-2 ): 1. In addition, when other comonomers are present, the molar content of the monomer isobutene may be 95.0-99.9 mol%.

As mentioned above, the reaction medium in the heterogeneous solution may be an organic solvent or an aqueous medium, and may also contain both an organic solvent and an aqueous medium. Wherein, the organic solvent can be selected from non-polar organic solvents (such as pentane, hexane, heptane, octane, methylcyclohexane, etc.), low-carbon halogenated hydrocarbons (such as methyl chloride, dichloromethane, etc.) methane) or a mixed solvent of two or more of them. The aqueous medium can be water and/or an aqueous reaction medium, wherein the water-soluble compound in the aqueous reaction medium is selected from the group consisting of alkali metal salts IAP or ammonium salts, inorganic protonic acids, organic acids and other ionic compounds or one or more of the alcohols. Wherein, IA is alkali metal lithium, sodium or potassium, and P is chlorine, bromine or acid radical. In addition, in the heterogeneous solution, the mass content of isobutene or a mixture of isobutene and other comonomers may be 5-50%.

According to the present invention, the co-initiator is preferably selected from the group conforming to the general structural formula MX _n or AlR _3-m X _m , wherein M is Al, Ti or Fe, X is a halogen atom, and R is with or without halogen or nitrate C ₂ -C ₁₀ substituted alkyl, aryl, arylalkyl or alkylaryl radical derived from the radical, m is 1, 2 or 3, and n is 3 or 4. Wherein, the MX _n can be selected from at least one of AlCl ₃ , TiCl ₄ and FeCl ₃ , and the AlR _3-m X _m can be selected from Al(C ₂ H ₅ )Cl ₂ , Al(C ₂ H ₅ ) ₂ Cl, Al(iC ₄ H ₉ )Cl ₂ , Al(iC ₄ H ₉ ) ₂ Cl, Al(C ₂ H ₅ ) _1.5 Cl _1.5 and at least one of Al(iC ₄ H ₉ ) _1.5 Cl _1.5 .

According to the present invention, the electron donor is preferably at least one of alcohol compounds, phenol compounds and ester compounds. Wherein, specific examples of the alcohol compounds include, but are not limited to: methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, penamyl alcohol , n-hexanol, n-heptanol, n-octanol, 2,2-dimethylpropanol, 2,3-dimethyl-2-butanol, 3,3-dimethyl-2-butanol, 2- Ethylbutanol, 2-methylpentanol, 3-ethyl-2-pentanol, 2,4-dimethylpentanol, 2-methyl-2-hexanol, 2-ethylbutanol, 2 ,3-dimethylpentanol, 2,4-dimethylpentanol, 2,3,4-trimethyl-3-pentanol, 2-methyl-3-ethylpentanol, 3,4- Dimethylhexanol, 3-methylheptanol, 2-propylpentanol, 2-ethylhexanol, dimethylheptanol, nonanol, decanol, linalool, benzyl alcohol, p-tolyl methanol and At least one of phenethyl alcohol. Specific examples of the phenolic compound include, but are not limited to: phenol, 2-methylphenol, 3-methylphenol, 4-methylphenol, 2-ethylphenol, 2,6-di-tert-butylphenol, and 2 , at least one of 6-di-tert-butyl-4-methylphenol. Specific examples of the ester compound include but are not limited to: methyl acetate, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, methyl acrylate, methyl methacrylate, methyl benzoate Ester, methyl hydroxybenzoate, ethyl benzoate, ethyl hydroxybenzoate, propyl benzoate, allyl benzoate, propyl hydroxybenzoate, butyl benzoate, butyl hydroxybenzoate, hydroxybenzoic acid Octyl ester, methyl toluate, ethyl toluate, ethyl phenylacetate, isobutyl phenylacetate, methyl hydroxyphenylacetate, ethyl hydroxyphenylacetate, dodecyl hydroxybenzoate, ten trihydroxybenzoate Hexaalkyl ester, n-hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate, methyl hydroxybenzoate, ethyl hydroxybenzoate, 3,5-bis(1,1-dimethyl hydroxybenzoate) At least one of butyl 4-hydroxyphenylpropionate, diallyl phthalate and diisooctyl phthalate.

The vinyl chloride resin can be obtained commercially or prepared by various existing methods. The vinyl chloride resin is the product of vinyl chloride through suspension polymerization, emulsion polymerization or bulk polymerization. The solid is preferably granular or powdery, and its particle size is preferably 0.1 μm or more, more preferably 0.2-500 μm, and further preferably 0.3- 400 μm, most preferably 0.5-370 μm.

According to the present invention, preferably, the temperature of the heterogeneous polymerization reaction is -100-25°C, more preferably -95-15°C, most preferably -90-5°C; the time is 1-150min, more preferably 2～90min, most preferably 3～40min.

The preparation method of the vinyl chloride resin compound further comprises: adding alcohols, ammonia, amines or water to the reaction system to terminate the polymerization after the heterogeneous polymerization reaction, adding alcohols or water to separate out the polymerization. After drying, the vinyl chloride resin composite was obtained. The alcohol or water is usually in excess. The alcohols include, but are not limited to, ethanol.

The present invention also provides the vinyl chloride resin composite prepared by the above method.

The present invention will be described in detail by the following examples.

(1) The weight-average molecular weight (M _w ) and molecular weight distribution index (M _w / _Mn ) of the polymer were determined by gel chromatography GPC, using tetrahydrofuran as the mobile phase, and the flow rate was 1 mL/min.

(2) Determination of the composition and content of the vinyl chloride resin composite: The total mass content of the branches of the isobutylene-based polymer segment in the vinyl chloride resin composite was determined by FTIR method.

(3) Determination of thermal stability of vinyl chloride resin composites: The thermal decomposition temperature of the composites was tested with a TAQ50 thermogravimetric analyzer (TGA), with a test range of 50-600° C., in a nitrogen atmosphere.

(4) Mechanical properties test of vinyl chloride resin composites: According to GB/T 1040-2006 "Test Method for Tensile Properties of Plastics", samples were prepared, and a universal material testing machine was used to test the mechanical properties of composite materials.

(5) Air tightness test of vinyl chloride resin composite: The oxygen permeability coefficient of the composite material was characterized by using a VAC-V2 differential pressure gas permeameter at 23°C. The smaller the oxygen transmission coefficient, the better the air tightness of the material.

Example 1

In the reaction vessel, add solid 150g PVC ( _Mw =98kg/mol, PDI=1.8, particle diameter is 20-170μm), add precooled isobutene/hexane solution 400mL, add aqueous medium (specifically sodium chloride, Potassium chloride, lithium chloride and water mass ratio=1:1:22:76) 400mL, stir to form a heterogeneous system; this heterogeneous system is mixed with a system containing FeCl ₃ and isopropanol, wherein PVC, The molar ratio of FeCl ₃ , isopropanol and isobutylene was 4.5×10 ⁻³ :5.1×10 ⁻² :7.1×10 ⁻² :1. The polymerization temperature was -75°C. After 5 min of polymerization, 50 mL of water was added to terminate the reaction; after termination, the reaction system was washed with water and hexane in turn, and repeated three times to obtain a PVC/PVC-g-PIB composite. Under vacuum drying at 40°C, the dried PVC/PVC-g-PIB composite can be obtained, which comprises polyvinyl chloride particles and a polyvinyl chloride graft copolymer coated on the surface of the polyvinyl chloride particles, The polyvinyl chloride graft copolymer is a polymer in which the main chain of polyvinyl chloride is connected with a plurality of isobutylene-based polymer chain branched chains, wherein the total mass content of the isobutylene-based polymer segment branches is 14 wt %.

The tensile strength of the prepared PVC/PVC-g-PIB composite was 44MPa, and the elongation at break was 28%. Compared with the PVC of Comparative Example 1, the tensile strength and elongation at break are significantly improved, which shows that it has the effect of strengthening and toughening, thereby realizing the in-situ strengthening and toughening of the PVC material and improving the performance of the material. .

The decomposition temperature corresponding to 5% weight loss of the prepared PVC/PVC-g-PIB composite was 278 °C, and the thermal stability of the composite was improved by 25 °C compared with the PVC of Comparative Example 1.

The oxygen permeability coefficient of the prepared PVC/PVC-g-PIB composite is 2.17×10 ^-15 cm ³ ·cm/cm ² ·s ·Pa, and the air tightness is improved by 20 times compared with the PVC of Comparative Example 1 .

Example 2

In reaction vessel, add 150g solid-state PVC (specifically with embodiment 1) and precooled isobutene/hexane solution 400mL and aqueous medium (specifically with embodiment 1) 400mL successively, form heterogeneous system; This heterogeneous system Mixed with the system containing AlCl ₃ and 3,5-di-tert-butyl-4-hydroxybenzoic acid n-hexadecyl ester (B), wherein the molar ratio of PVC, AlCl ₃ , B and isobutylene is 4.5×10 ^-3 : 1.0 ×10 ^-2 : 3.0 × 10 ^-3 : 1. The polymerization temperature was -75°C, and the polymerization reaction was terminated after 5 min. The post-treatment method of the polymer is the same as that in Example 1, and a dried PVC/PVC-g-PIB composite is obtained, wherein the total mass content of the branched chain of the isobutene-based polymer segment is 34 wt %.

The tensile strength of the prepared PVC/PVC-g-PIB composite was 35MPa, and the elongation at break was 45%. Compared with the PVC of Comparative Example 1, the tensile strength and elongation at break are significantly improved, which shows that it has the effect of strengthening and toughening (see Figure 1), thus realizing the in-situ strengthening and toughening of the PVC material, which is obvious. The performance of the material is improved, and the performance is significantly better than the corresponding performance of the blend of PVC and PIB (Comparative Example 2).

The decomposition temperature corresponding to 5% weight loss of the prepared PVC/PVC-g-PIB composite was 295°C. Compared with the PVC of Comparative Example 1, the thermal stability of the composite was improved by 42°C.

The oxygen permeability coefficient of the prepared PVC/PVC-g-PIB composite is 3.51×10 ^-15 cm ³ ·cm/cm ² ·s ·Pa, and the air tightness is improved by 12 times compared with the PVC of Comparative Example 1 .

Example 3

In reaction vessel, add 3g solid-state PVC (specifically with embodiment 1) and precooled isobutene/hexane solution 20mL and aqueous medium (specifically with embodiment 1) 20mL successively, form heterogeneous system; This heterogeneous system Mixed with a system containing dichloroethylaluminum (E) and n-hexadecyl 3,5-di-tert-butyl-4-hydroxybenzoate (B), wherein the molar ratio of PVC, E, B and isobutylene is 1.8× 10 ⁻³ : 8.0×10 ⁻³ : 8.0×10 ⁻⁴ : 1. The polymerization temperature was -65°C, and the polymerization reaction was terminated after 150 min. The post-treatment method of the polymer is the same as that in Example 1, and a dried PVC/PVC-g-PIB composite is obtained, wherein the total mass content of the branched chains of the isobutene-based polymer segment is 17 wt %.

The tensile strength of the prepared PVC/PVC-g-PIB composite was 41 MPa, and the elongation at break was 32%. Compared with the PVC of Comparative Example 1, the tensile strength and elongation at break are significantly improved, which shows that it has the effect of strengthening and toughening, thereby realizing the in-situ strengthening and toughening of the PVC material, and significantly improving the performance of the material. .

The decomposition temperature corresponding to 5% weight loss of the prepared PVC/PVC-g-PIB composite was 288°C, and compared with the PVC of Comparative Example 1, the thermal stability was improved by 35°C.

The oxygen permeability coefficient of the prepared PVC/PVC-g-PIB composite was 2.51×10 ^-15 cm ³ ·cm/cm ² ·s ·Pa, and the air tightness was improved by 17 compared with the PVC of Comparative Example 1. times.

Example 4

In the reaction vessel, add 3g solid PVC (specifically with embodiment 1) and precooled isobutene/hexane solution 20mL and aqueous medium 20mL (specifically with embodiment 1) successively, form heterogeneous system; This heterogeneous system Mixed with a system containing FeCl ₃ and isopropanol, wherein the molar ratio of PVC, FeCl ₃ , isopropanol and isobutene is 4.5×10 ⁻³ : 4.5×10 ⁻² : 6.3×10 ⁻² :1. The polymerization temperature was -60°C, and the polymerization reaction was terminated after 20 min. The post-treatment method of the polymer is the same as that of Example 1, and the dried PVC/PVC-g-PIB composite is obtained, wherein the total mass content of the branched chain of the isobutene-based polymer segment is 12 wt %.

The tensile strength of the prepared PVC/PVC-g-PIB composite was 46MPa, and the elongation at break was 24%. Compared with the PVC of Comparative Example 1, the tensile strength and elongation at break are significantly improved, which shows that it has the effect of strengthening and toughening, thereby realizing the in-situ strengthening and toughening of the PVC material and improving the performance of the material.

The decomposition temperature corresponding to 5% weight loss of the prepared PVC/PVC-g-PIB composite was 272 °C. Compared with the PVC of Comparative Example 1, the corresponding decomposition temperature of 5% weight loss was increased by 19 °C, and the thermal stability of the composite was improved. improve.

The oxygen permeability coefficient of the prepared PVC/PVC-g-PIB composite is 3.88×10 ^-15 cm ³ ·cm/cm ² ·s ·Pa, and the air tightness is improved by 11 times compared with the PVC of Comparative Example 1 .

Example 5

In the reaction vessel, add 150g solid-state PVC (specifically with embodiment 1) and precooled isobutene/hexane solution 400mL and aqueous medium (with embodiment 1) 400mL successively, form heterogeneous system; This heterogeneous system and A system containing AlCl ₃ and B was mixed, wherein the molar ratio of PVC, AlCl ₃ , B and isobutylene was 4.5×10 ⁻³ :1.0×10 ⁻² :3.0×10 ⁻³ :1. The polymerization temperature was -62°C, and the polymerization reaction was terminated after 5 min. The post-processing method of the polymer is the same as that in Example 1, and a PVC/PVC-g-PIB composite is obtained, wherein the total mass content of the branched chains of the isobutene-based polymer segment is 24 wt %.

The tensile strength of the prepared PVC/PVC-g-PIB composite was 32MPa, and the elongation at break was 36%. Compared with the PVC of Comparative Example 1, the tensile strength and elongation at break are significantly improved, which shows that it has the effect of strengthening and toughening, thereby realizing the in-situ strengthening and toughening of the PVC material, and improving the performance of the material. And the performance is significantly better than that of the PIB/PVC blend (with a PIB content of 20%) (Comparative Example 3).

The decomposition temperature corresponding to 5% weight loss of the prepared PVC/PVC-g-PIB composite was 287°C. Compared with the PVC of Comparative Example 1, the thermal stability of the composite was improved by 35°C.

The oxygen permeability coefficient of the prepared PVC/PVC-g-PIB composite is 2.48×10 ^-15 cm ³ ·cm/cm ² ·s ·Pa, and the air tightness is improved by 17 times compared with the PVC of Comparative Example 1 .

Example 6

In the reaction vessel, add 150g solid-state PVC particles (specifically the same as Example 1) and 500mL of precooled isobutene/hexane solution and 500mL of deionized water to form a heterogeneous system; this heterogeneous system is mixed with _FeCl and isopropyl. The alcohol system was mixed, wherein the molar ratio of PVC, FeCl ₃ , isopropanol and isobutylene was 4.5×10 ⁻³ :4.4×10 ⁻² :6.16×10 ⁻² :1. The polymerization temperature was 0°C, and the polymerization reaction was terminated after 10 min. The post-treatment method of the polymer is the same as that in Example 1, and a dried PVC/PVC-g-PIB composite is obtained, wherein the total mass content of the branched chains of the isobutene-based polymer segment is 11 wt %.

The tensile strength of the prepared PVC/PVC-g-PIB composite was 42 MPa, and the elongation at break was 18%. Compared with the PVC of Comparative Example 1, the tensile strength and elongation at break are significantly improved, which shows that it has the effect of strengthening and toughening, thereby realizing the in-situ strengthening and toughening of the PVC material, and improving the performance of the material. And the performance is obviously better than the corresponding performance of PVC and PIB blend (Comparative Example 2).

The decomposition temperature corresponding to 5% weight loss of the prepared PVC/PVC-g-PIB composite was 279°C, and compared with the PVC of Comparative Example 1, the thermal stability of the composite was improved by 26°C.

The oxygen permeability coefficient of the prepared PVC/PVC-g-PIB composite is 4.02×10 ^-15 cm ³ ·cm/cm ² ·s ·Pa, and the air tightness is improved by 10 times compared with the PVC of Comparative Example 1 .

Example 7

150g of solid PVC particles (M _w =210kg/mol, PDI=2.3, particle size of 120-330μm) and 500mL of pre-cooled isobutene/hexane solution were added to the reaction vessel to form a heterogeneous system; the heterogeneous system Mixed with a system containing FeCl ₃ and isopropanol, wherein the molar ratio of PVC, FeCl ₃ , isopropanol and isobutene was 4.5×10 ⁻³ : 4.4×10 ⁻² : 6.16×10 ⁻² :1. The polymerization temperature was -80°C, and the polymerization reaction was terminated after 5 min. The post-processing method of the polymer is the same as that in Example 1, to obtain a PVC/PVC-g-PIB compound, wherein the total mass content of the branched chain of the isobutene-based polymer segment is 14wt%

The tensile strength of the prepared PVC/PVC-g-PIB composite was 39 MPa, and the elongation at break was 21%. Compared with the PVC of Comparative Example 1, the tensile strength and elongation at break are significantly improved, which shows that it has the effect of strengthening and toughening, thereby realizing the in-situ strengthening and toughening of the PVC material, and improving the performance of the material. And the performance is obviously better than the corresponding performance of PVC and PIB blend (Comparative Example 2).

The decomposition temperature corresponding to 5% weight loss of the prepared PVC/PVC-g-PIB composite was 289°C, and the thermal stability of the composite was improved by 36°C compared with the PVC of Comparative Example 1.

The oxygen permeability coefficient of the prepared PVC/PVC-g-PIB composite is 3.08×10 ^-15 cm ³ ·cm/cm ² ·s ·Pa, and the air tightness is improved by 14 times compared with the PVC of Comparative Example 1 .

Example 8

150g solid PVC (M _w =76kg/mol, PDI=2.1, particle size is 20-200μm) and 500mL of pre-cooled isobutene/hexane solution were successively added to the reaction vessel to form a heterogeneous system; the heterogeneous system It is mixed with a system containing FeCl ₃ and isopropanol, wherein the molar ratio of PVC, FeCl ₃ , isopropanol and isobutylene is 4.5×10 ^-3 : 4.4×10 ^-2 : 6.16×10 ^-2 : 1, and the polymerization temperature is -80°C, the polymerization reaction was terminated after 5 min. The post-treatment method of the polymer is the same as that in Example 1, and a PVC/PVC-g-PIB composite is obtained, wherein the total mass content of the branched chains of the isobutene-based polymer segment is 12 wt %.

The tensile strength of the prepared PVC/PVC-g-PIB composite was 35MPa, and the elongation at break was 11%. Compared with the PVC of Comparative Example 1, the tensile strength and elongation at break are significantly improved, which shows that it has the effect of strengthening and toughening, thereby realizing the in-situ strengthening and toughening of the PVC material, improving the material properties, and The performance is significantly better than the corresponding performance of the blend of PVC and PIB (Comparative Example 2).

The decomposition temperature corresponding to 5% weight loss of the prepared PVC/PVC-g-PIB composite was 297°C. Compared with the PVC of Comparative Example 1, the thermal stability of the composite was improved by 44°C.

The oxygen permeability coefficient of the prepared PVC/PVC-g-PIB composite is 3.56×10 ^-15 cm ³ ·cm/cm ² ·s ·Pa, and the air tightness is improved by 12 times compared with the PVC of Comparative Example 1 .

Example 9

20g solid PVC (M _w =335kg/mol, PDI ₌ 3.0, particle size is 0.1-2 μm) and 100mL of pre-cooled isobutene/hexane solution were successively added to the reaction vessel to form a heterogeneous system; It is mixed with a system of isopropanol, wherein the molar ratio of PVC, FeCl ₃ , isopropanol and isobutene is 4.5×10 ⁻³ : 2.0×10 ⁻² : 2.8×10 ⁻² :1. The polymerization temperature was -80°C, and the polymerization reaction was terminated after 5 min. The post-treatment method of the polymer is the same as that in Example 1, to obtain a PVC/PVC-g-PIB composite, wherein the total mass content of the branched chain of the isobutene-based polymer segment is 20 wt%.

Comparative Example 1

The solid PVC particles (same as in Example 1) were prepared as film materials, and the mechanical properties were tested. The tensile strength was 32 MPa and the elongation at break was 2%.

The 5% weight loss of the PVC corresponds to a thermal decomposition temperature of 253°C.

The oxygen transmission coefficient of this PVC was 42.9×10 ⁻¹⁵ cm ³ ·cm/cm ² ·s·Pa.

Comparative Example 2

The solid PVC particles (same as in Example 1) and PIB (M _w =138kg/mol) were blended with a twin-screw extruder in a mass ratio of 7:3, the mixing temperature was 180°C, and the screw speed was 50r/min, A PVC/PIB binary blend was obtained, wherein the mass fraction of PIB was 30%. The tensile strength was 9.4 MPa, and the elongation at break was 7%.

Comparative Example 3

The solid PVC particles (same as in Example 1) and PIB (same as in Comparative Example 2) are blended with a twin-screw extruder in a mass ratio of 8:2, the mixing temperature is 180° C., and the screw speed is 50 r/min to obtain PVC. /PIB binary blend, wherein the mass fraction of PIB is 20%. The tensile strength was 12.5 MPa, and the elongation at break was 5%.

Various embodiments of the present invention have been described above, and the foregoing descriptions are exemplary, not exhaustive, and not limiting of the disclosed embodiments. Numerous modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims (10)

1. A vinyl chloride resin composite comprising a solid vinyl chloride resin and a vinyl chloride resin graft copolymer coated on the surface of the vinyl chloride resin, wherein the vinyl chloride resin is at least one selected from the group consisting of polyvinyl chloride, chlorinated polyvinyl chloride and a copolymer of vinyl chloride and vinyl acetate, the vinyl chloride resin graft copolymer is a polymer having a main chain of polyvinyl chloride, chlorinated polyvinyl chloride or a copolymer of vinyl chloride and vinyl acetate and having a plurality of chain branches of an isobutylene-based polymer segment connected thereto, and the total mass content of the chain branches of the isobutylene-based polymer segment is 5 to 50 wt%, preferably 7 to 45 wt%, more preferably 9 to 40 wt%, based on the total mass of the vinyl chloride resin composite.

2. The vinyl chloride resin composite according to claim 1, wherein the isobutylene-based polymer segment branch is an isobutylene homo-segment or a copolymerized segment of isobutylene and other comonomers; when the chain segment branch of the isobutylene-based polymer is a copolymerization segment of isobutylene and other comonomers, the molar content of isobutylene structural units is 95.0 to 99.9 mol%; the other comonomer is conjugated diene and/or vinyl aromatic hydrocarbon.

3. The vinyl chloride resin composite according to claim 1 or 2, wherein the polymer weight average molecular weight M of the vinyl chloride resin_wFrom 50 to 400kg/mol, preferably from 60 to 380kg/mol, more preferably from 70 to 350 kg/mol; molecular weight distribution index M_w/M_nIs 1.3 to 4.0, preferably 1.4 to 3.5, more preferably 1.5 to 3.2.

4. The vinyl chloride resin composite according to claim 1 or 2, wherein the vinyl chloride resin is in the form of particles or powder, and has a particle diameter of 0.1 μm or more, preferably 0.2 to 500 μm.

5. A method for preparing a vinyl chloride resin composite, the method comprising: vinyl chloride resins in solid form are polymerized heterogeneously with isobutene or with a mixture of isobutene and other comonomers in the presence of a coinitiator and an electron donor.

6. The production method according to claim 5,

the heterogeneous polymerization reaction method comprises the following steps:

A. mixing solid vinyl chloride resin with isobutene and other comonomers optionally contained to form a heterogeneous system, wherein the heterogeneous system contains or does not contain a reaction medium, the reaction medium is an organic solvent or an aqueous phase medium or contains both an organic solvent and an aqueous phase medium, and the organic solvent is an inert liquid organic matter which does not dissolve the solid vinyl chloride resin but can disperse or swell the solid vinyl chloride resin;

B. mixing the reaction system formed in the step A with a coinitiator and an electron donor to initiate heterogeneous polymerization;

preferably, the method further comprises: and after the heterogeneous polymerization reaction is finished, adding alcohol substances, ammonia, amine substances or water into the reaction system to terminate the polymerization reaction, adding alcohol substances or water to precipitate a polymer, and drying to obtain the vinyl chloride resin compound.

7. The production method according to claim 5 or 6, wherein the molar ratio of the vinyl chloride resin, the co-initiator, the electron donor and the isobutylene is (1.2 x 10)^-3-6.0×10^-3)：(5.0×10^-3-8.0×10^-2)：(6.0×10^-4-8.0×10^-2)：1；

Preferably, the coinitiator is selected according to the general structural formula MX_nOr AlR_3-mX_mWherein M is Al, Ti or Fe, X is a halogen atom, and R is C with or without halogen or nitro-derived substitution₂-C₁₀M is 1, 2 or 3, n is 3 or 4; preferably, said MX_nSelected from AlCl₃、TiCl₄And FeCl₃At least one of (1), the AlR_3-mX_mSelected from Al (C)₂H₅)Cl₂、Al(C₂H₅)₂Cl、Al(i-C₄H₉)Cl₂、Al(i-C₄H₉)₂Cl、Al(C₂H₅)_1.5Cl_1.5And Al (i-C)₄H₉)_1.5Cl_1.5At least one of;

preferably, the electron donor is at least one of an alcohol compound, a phenol compound and an ester compound; the alcohol compound is selected from methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, t-butanol, n-pentanol, isopentanol, quaternary pentanol, n-hexanol, n-heptanol, n-octanol, 2-dimethylpropanol, 2, 3-dimethyl-2-butanol, 3-dimethyl-2-butanol, 2-ethylbutanol, 2-methylpentanol, 3-ethyl-2-pentanol, 2, 4-dimethylpentanol, 2-methyl-2-hexanol, 2-ethylbutanol, 2, 3-dimethylpentanol, 2, 4-dimethylpentanol, 2,3, 4-trimethyl-3-pentanol, 2-methyl-3-ethylpentanol, 3, 4-dimethylhexanol, 3-methylheptanol, heptanol, At least one of 2-propylpentanol, 2-ethylhexanol, dimethylheptanol, nonanol, decanol, linalool, benzyl alcohol, p-tolyl methanol, and phenethyl alcohol; the phenolic compound is selected from at least one of phenol, 2-methylphenol, 3-methylphenol, 4-methylphenol, 2-ethylphenol, 2, 6-di-tert-butylphenol and 2, 6-di-tert-butyl-4-methylphenol; the ester compound is selected from methyl acetate, methyl acetoacetate, ethyl acetoacetate, propyl acetoacetate, butyl acetoacetate, methyl acrylate, methyl methacrylate, methyl benzoate, methyl hydroxybenzoate, ethyl benzoate, ethyl hydroxybenzoate, propyl benzoate, allyl benzoate, propyl hydroxybenzoate, butyl benzoate, butyl hydroxybenzoate, octyl hydroxybenzoate, methyl toluate, ethyl phenylacetate, isobutyl phenylacetate, methyl hydroxybenzoate, ethyl hydroxybenzoate, dodecyl hydroxybenzoate, hexadecyl hydroxybenzoate, n-hexadecyl 3, 5-di-tert-butyl-4-hydroxybenzoate, methyl hydroxyphenylpropionate, ethyl hydroxyphenylpropionate, 3, 5-di (1, 1-dimethylethyl) -4-hydroxyphenylpropionate, butyl hydroxybenzoate, methyl methacrylate, ethyl hydroxybenzoate, ethyl methacrylate, ethyl hydroxybenzoate, ethyl methacrylate, methyl methacrylate, ethyl hydroxybenzoate, butyl methacrylate, ethyl hydroxybenzoate, methyl methacrylate, ethyl hydroxybenzoate, at least one of diallyl phthalate and diisooctyl phthalate.

8. The production method according to claim 5 or 6, wherein the vinyl chloride resin is in the form of particles having a particle diameter of 0.1 μm or more, preferably 0.2 to 500 μm.

9. The preparation method according to claim 5 or 6, wherein the temperature of the heterogeneous polymerization reaction is-100 to 25 ℃, preferably-95 to 15 ℃, and more preferably-90 to 5 ℃; the time is 1-150 min, preferably 2-90 min, and more preferably 3-40 min.

10. A vinyl chloride resin composite prepared by the method of any one of claims 5 to 9.

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