Modified heat-resistant polystyrene material as well as preparation method and application thereof

Abstract

The invention provides a modified heat-resistant polystyrene material as well as a preparation method and application thereof, and belongs to the field of alloy materials. According to the invention, blending of polystyrene and polypropylene is modified by the oil compatibilizer, and the modified oil in the oil compatibilizer weakens the action among material molecules, so that the motion range of chain segments is enlarged, and the flexibility of molecular chains is improved; when the oily compatilizer is mixed with polystyrene and polypropylene, the oily compatilizer interacts with molecular chains of the polystyrene and the polypropylene, so that the interfacial tension between two phases is effectively reduced, the phase interface bonding force of the modified heat-resistant polystyrene material is enhanced, the phase interface can better transfer and disperse stress when being impacted by external force, and the heat-resistant performance of the modified heat-resistant polystyrene material is improved. The preparation method has the advantages that the rapid fracture of the material caused by stress concentration is avoided, and meanwhile, the comprehensive performance of the material is improved under specific processing parameters and modification conditions.

Description

Technical Field

[0001] The present invention relates to the field of alloy materials, and particularly to a modified heat-resistant polystyrene material, a preparation method thereof, and an application thereof. Background Art

[0002] Polystyrene (PS) is widely used in the fields of packaging, electronic appliances, etc. due to its high rigidity, excellent dimensional stability, and easy processability. However, the inherent defects of PS, such as high brittleness and poor impact resistance, especially brittle fracture prone to occur under low temperature or high load conditions, severely restrict its application in the field of structural parts. To break through this bottleneck, researchers have tried to introduce polypropylene (PP) as a modified material to construct PS-based composites. With its excellent toughness, chemical corrosion resistance, and relatively high heat distortion temperature, PP can theoretically effectively compensate for the brittle defects of PS and achieve synergistic enhancement of stiffness-toughness balance. However, the significant difference in molecular polarity between PS and PP leads to extremely poor interfacial compatibility between the two phases. Simple physical blending easily causes macroscopic phase separation, coarsening of the dispersed phase size, and insufficient interfacial adhesion, which instead deteriorates the key mechanical properties such as the impact strength of the composite material compared to the pure PS matrix.

[0003] To solve the problem of compatibility between polypropylene and polystyrene, compatibilizers such as styrene-butadiene-styrene block copolymer (SBS), styrene-ethylene / butylene-styrene block copolymer (SEBS), or maleic anhydride grafted polypropylene (PP-g-MAH) are often used to improve the interfacial bonding force between the two. By the polar matching of molecular chain segments with PP and PS respectively, the interfacial tension is reduced, promoting the refinement and stabilization of the dispersed phase.

[0004] For example, CN103467875A discloses a polystyrene composite material for improving demoulding property using waste oil and a preparation method thereof. The composition of the polystyrene composite material is: impact-resistant polystyrene 70-80wt%, polystyrene 10-20wt%, SBS rubber 5-10wt%, polypropylene 3-5wt%, waste oil 0.3-1.5wt%, antioxidant 0.1-0.5wt%.

[0005] And a method for preparing an alloy material by mixing polystyrene and polypropylene materials to improve the properties of the materials. For example, Patent CN115386191A discloses a compatibilizer applied to a PP / PS alloy. The compatibilizer is composed of 90 to 100 parts by weight of a main material and 0 to 10 parts by weight of an auxiliary material; wherein, the main material contains at least 50 parts by weight of a first main material component and at least 20 parts by weight of a second main material component; the first main material component is a styrene-butadiene-styrene copolymer, and the second main material component is an elastomer; the auxiliary material contains a graft modifier, a co-reactant, an initiator, an antioxidant, a lubricant, methyl silicone oil, and linear low-density polyethylene powder. Thus, it can be seen that the compatibilizer plays a great role when polystyrene and polypropylene are mixed.

[0006] CN103881234A discloses a high-impact polystyrene-modified stress-whitening-resistant polypropylene composite and a preparation method thereof. A high-impact polystyrene masterbatch is added to the compounding for preparing the above polypropylene composite. The polypropylene and the high-impact polystyrene in the masterbatch are compatible through an SEBS graft, and the rubber particles in the high-impact polystyrene are uniformly and firmly dispersed in the matrix; a filling masterbatch is added to the compounding. The coupling agent and the polypropylene graft in the filling masterbatch tightly bond the polypropylene resin and the inorganic filler interface, and the two phases are not easily peeled off. Then, the filling masterbatch is used as a base material for re-melting and extrusion granulation.

[0007] After mixing polystyrene and polypropylene through a compatibilizer, and then adding toughening agents and other materials to modify polystyrene, the processability, impact resistance, heat resistance, etc. of the prepared material will be significantly improved. However, the mixing conditions of maleic anhydride graft compatibilizers are relatively strict, and they are more sensitive to parameters such as temperature and time during the processing, and maleic anhydride graft compatibilizers may also produce side reactions, resulting in unwanted cross-linking and degradation between components, thereby affecting the performance of the blended material. In addition, the heat resistance and toughening effect of conventional SBS compatibilizers are also relatively poor. After processing parts, the material will still deform under high-temperature conditions, and the SBS compatibilizer may increase the viscosity of the blended material, resulting in an increase in the processing difficulty of the blended material.

[0008] In summary, blending polypropylene with polystyrene and modifying polystyrene can combine the toughness and chemical resistance of PP with the rigidity and dimensional stability of PS. However, due to the large polarity difference between the two, the interfacial compatibility is poor. Therefore, a compatibilizer needs to be added during the processing to improve the dispersion of the two. However, the processability of conventional maleic anhydride graft compatibilizers and SBS compatibilizers has disadvantages during use, and problems such as poor impact resistance, low heat resistance, side reactions, and poor compatibility of the materials prepared using the current compatibilizers still need to be urgently solved. Summary of the Invention

[0009] In view of the above problems, the present invention provides a modified heat-resistant polystyrene material, a preparation method thereof, and an application thereof. By preparing an oil-based compatibilizer, polystyrene and polypropylene are melt-mixed, and then mixed with other additives to obtain an alloy material with good compatibility, good impact resistance, and good heat resistance.

[0010] The present invention provides a modified heat-resistant polystyrene material, which is prepared by modifying polystyrene and polypropylene with an oil-based compatibilizer and additives; the density of the modified heat-resistant polystyrene material is 1.04 - 1.06 g / cm 3 , and the melt index of the modified heat-resistant polystyrene material at 230 °C and 2.16 kg is 5.5 - 14 g / 10 min; the tensile strength of the modified heat-resistant polystyrene material is 21 - 28 MPa, the elongation at break is 30 - 50%, the flexural strength is 35 - 45 MPa, the flexural modulus is 1600 - 1700 MPa, the Izod notched impact strength is 290 - 330 J / m, and the Rockwell hardness is 50 - 80; the modified heat-resistant polystyrene material has good compatibility; the self-weight deformation of the modified heat-resistant polystyrene material after being placed at 120 °C for 3 h is 3 - 5 mm.

[0011] Further, the additives include a toughening agent, a reinforcing agent, an antioxidant, a lubricant, and a light stabilizer.

[0012] Further, the components and contents in the modified heat-resistant polystyrene material are as follows: Polystyrene: 30 - 80 parts by weight; Polypropylene: 5 - 20 parts by weight; Oil-based compatibilizer: 10 - 20 parts by weight; Toughening agent: 5 - 20 parts by weight; Reinforcing agent: 5 - 20 parts by weight; Antioxidant: 0.1 - 1 part by weight; Lubricant: 0.1 - 1 part by weight; Light stabilizer: 0.01 - 1 part by weight.

[0013] Further, the melt index of the oil-based compatibilizer at 190 °C and 2.16 kg is 0.1 - 20 g / 10 min.

[0014] Further, the oil-based compatibilizer is prepared by spraying and modifying an oil with a conventional compatibilizer under stirring at room temperature.

[0015] Further, the mass ratio of the conventional compatibilizer to the modified oil is (1:9) - (9:1).

[0016] Further, the conventional compatibilizer includes one or more of polystyrene-butadiene-styrene (SBS), hydrogenated styrene-butadiene block copolymer (SEBS), ethylene-vinyl acetate copolymer (EVA), ethylene propylene diene monomer (EPDM), styrene-isoprene-styrene block copolymer (SIS), chlorinated polyethylene (CPE), and styrene-butadiene copolymer (SBR).

[0017] Further, the modified oil includes one or both of paraffin oil and naphthenic oil.

[0018] Further, the stirring speed is 300 - 500 rpm, and the stirring time is 5 - 20 min.

[0019] The present invention also provides a method for preparing the modified heat-resistant polystyrene material, including the following steps: weighing each component according to the ratio of each component; Step 1, preparing an oil-modified compatibilizer At room temperature, spray the modified oil onto the stirred conventional compatibilizer to obtain an oil-modified compatibilizer; Step 2, adding polystyrene, polypropylene, the oil-modified compatibilizer, toughening agent, reinforcing agent, antioxidant, lubricant, and light stabilizer into a high-speed mixer for mixing, and feeding the mixed material into the main feeding port of a twin-screw extruder to obtain the modified heat-resistant polystyrene material.

[0020] Further, in Step 1, the melt index of the oil-modified compatibilizer at 190 °C and 2.16 kg is 0.1 - 20 g / 10 min.

[0021] Further, in Step 1, the stirring speed is 300 - 500 rpm, and the stirring time is 5 - 20 min.

[0022] Further, in Step 1, the mass ratio of the conventional compatibilizer to the modified oil is (1:9) - (9:1).

[0023] Further, in Step 1, the modified oil includes one or both of paraffin oil and naphthenic oil.

[0024] Further, in Step 1, the conventional compatibilizer includes one or more of polystyrene-butadiene-styrene (SBS), hydrogenated styrene-butadiene block copolymer (SEBS), ethylene-vinyl acetate copolymer (EVA), ethylene propylene diene monomer (EPDM), styrene-isoprene-styrene block copolymer (SIS), chlorinated polyethylene (CPE), and styrene-butadiene copolymer (SBR).

[0025] Further, the mass ratio of the polystyrene, the polypropylene, the oil-compatible agent, the toughening agent, the reinforcing agent, the antioxidant, the lubricant, and the light stabilizer in the step 2 is (30 - 80):(5 - 20):(10 - 20):(5 - 20):(5 - 20):(0.1 - 1):(0.1 - 1):(0.01 - 1).

[0026] Further, the melt index of the polystyrene in the step 2 at 200 °C and 5 kg is 3 - 15 g / 10 min.

[0027] Further, the polystyrene in the step 2 includes one or both of general polystyrene (GPPS) and high impact polystyrene (HIPS).

[0028] Further, when both the general polystyrene and the high impact polystyrene are present, the melt index ratio of the polystyrene with a high melt index to the polystyrene with a low melt index < 3.

[0029] Further, the melt index of the polypropylene in the step 2 at 230 °C and 2.16 kg is 3 - 60 g / 10 min.

[0030] Further, the polypropylene in the step 2 includes one or both of homopolypropylene and copolymer polypropylene.

[0031] Further, when both the homopolypropylene and the copolymer polypropylene are present, the melt index ratio of the polypropylene with a high melt index to the polypropylene with a low melt index < 3.

[0032] Further, the toughening agent in the step 2 includes one or more of ethylene-octene copolymer (POE), linear low density polyethylene (LLDPE), low density polyethylene (LDPE), and high density polyethylene (HDPE).

[0033] Further, the reinforcing agent in the step 2 includes one or more of talc, calcium carbonate, kaolin, and silica.

[0034] Further, the antioxidant in the step 2 includes one or both of hindered phenol antioxidants and phosphite antioxidants.

[0035] Further, the hindered phenol antioxidants include one or more of 2,6-di-tert-butyl-4-methylphenol (antioxidant 264), pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010), and octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (antioxidant 1076).

[0036] Further, the phosphite antioxidant includes one or both of tris(2,4-di-tert-butylphenyl) phosphite (Antioxidant 168) and bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite (Antioxidant 242).

[0037] Further, the lubricant in step 2 includes one or more of calcium stearate, glycerol stearate, and ethylene bisstearamide.

[0038] Further, the light stabilizer in step 2 includes one or both of poly(4-hydroxy-2,2,6,6-tetramethyl-1-piperidylethyl) succinate (UV-622) and 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (UV-234).

[0039] Further, the rotation speed of the high-speed mixer in step 2 is 300 - 500 rpm, and the mixing time is 1 - 5 min.

[0040] Further, the processing temperature of the twin-screw extruder in step 2 is 180 - 200 °C Further, the screw rotation speed of the twin-screw extruder in step 2 is 100 - 500 rpm.

[0041] Further, the length-to-diameter ratio of the twin-screw extruder in step 2 is (16 - 52):1.

[0042] Further, the head temperature of the twin-screw extruder in step 2 is 190 - 230 °C.

[0043] Further, the torque of the twin-screw extruder in step 2 is 40 - 70 N·m.

[0044] Further, the main motor current of the twin-screw extruder in step 2 is 400 - 550 A.

[0045] Further, the melt temperature of the twin-screw extruder in step 2 is 200 - 270 °C.

[0046] Further, the feeding speed at the main feeding port of the twin-screw extruder in step 2 is 30 - 700 kg / h.

[0047] The present invention also provides an automobile or electrical appliance packaging, and the raw material of the automobile or electrical appliance packaging includes the modified heat-resistant polystyrene material.

[0048] Advantages of the present invention: 1. In the present invention, the molecular chain of polystyrene has a certain degree of regularity and rigidity, endowing the material with relatively high hardness and stiffness, enabling it to maintain good shape stability, not easily deformed, and having good processing fluidity and transparency. However, its heat resistance temperature is low, only about 70 - 90 °C; while polypropylene has good heat resistance, about 160 - 170 °C, good processability, strong stability, and relatively low cost, but poor impact resistance; when polypropylene modifies polystyrene, polypropylene imparts certain crystallization properties to the modified heat-resistant polystyrene material to improve the heat resistance of the material, and also maintains excellent impact resistance. At the same time, in the present invention, an oil-based compatibilizer is used to modify the compatibility of polystyrene and polypropylene. Among them, when the modified oil in the oil-based compatibilizer is mixed with a conventional compatibilizer, the molecular chain can be compatible with the PB segment in the conventional compatibilizer to achieve the effect of oilification; 2. When the oil-based compatibilizer is mixed with polystyrene and polypropylene in the present invention, the modified oil weakens the intermolecular interaction of each material, increases the mobility of the molecular chain, enlarges the movement range of the chain segment, enables the chain segment to fully stretch during stretching, and is easy to recover after the external force is removed, increasing the molecular chain flexibility; when the oil-based compatibilizer is mixed with polystyrene and polypropylene, it interacts with the molecular chains of both, effectively reducing the interfacial tension between the two phases and enhancing the interfacial bonding force of the modified heat-resistant polystyrene material.

[0049] 3. In addition to using polypropylene and an oil-based compatibilizer to modify polystyrene in the present invention, toughening agents, reinforcing agents and other additives are also added. Under specific temperature and parameter settings of a twin-screw extruder, the material in the present invention is prepared. The impact resistance of the modified heat-resistant polystyrene material is increased by more than 30% compared with the prior art. This is because when the modified material is subjected to external force impact, the phase interface can better transfer and disperse stress, avoiding the rapid rupture of the material caused by stress concentration. At the same time, the processability of the material is also good; 4. Under the processing conditions in the present invention, the temperature-sensitive polypropylene and shear-sensitive polystyrene have similar viscosities in the molten state, making it easier to achieve kinetic compatibility between materials. During the dynamic rheological processing, by applying specific shear force and strain conditions, polypropylene and polystyrene are induced to form a finer and more uniform phase structure, which also improves the stability of the material, reduces the differences between different batches of products, and the difference in tensile strength is about 5%. At the same time, at the relatively low processing temperature in the present invention, each component also avoids the possibility of thermal degradation, improving the comprehensive performance of the material. Description of the Drawings

[0050] Figure 1 It is the infrared spectrum diagram of the modified heat-resistant polystyrene material described in Example 1; Figure 2 It is the self-weight deformation state diagram of the modified heat-resistant polystyrene material described in Example 1; Figure 3 The self-weight deformation state diagram of the commercial polystyrene material described in Comparative Example 1; Figure 4 The state diagram after bending of the modified heat-resistant polystyrene materials described in Examples 1, 2 and Comparative Example 2. Detailed Description of the Invention

[0051] The invention will be described in detail below with reference to the embodiments: The present invention provides a modified heat-resistant polystyrene material, its preparation method and application. By preparing an oil-based compatibilizer, the compatibility between polystyrene and polypropylene is greatly improved, and the impact resistance and heat resistance of the material are improved by utilizing the self-advantages of polystyrene and polypropylene.

[0052] In the following examples: In Example 1, the aspect ratio is 40:1, the compatibilizer is oil-based SBS, and the toughening agent is POE; In Example 2, the aspect ratio is 52:1, the compatibilizer is oil-based SBS, and the toughening agent is HDPE; In Example 3, the aspect ratio is 40:1, the compatibilizer is oil-based SEBS, and the toughening agent is POE; Comparative Example 1 is a commercial polystyrene material; Comparative Example 2 is the same as Example 1, except that the general polystyrene is 55 parts by weight, the high-impact polystyrene is 10 parts by weight, the polypropylene is 15 parts by weight, and the oil-based compatibilizer is not added; Comparative Example 3 is the same as Example 1, except that the compatibilizer is not oil-based, but only ordinary SBS; Comparative Example 4 is the same as Example 1, except that the compatibilizer is a traditional compatibilizer - maleic anhydride.

[0053] Example 1 This example provides a modified heat-resistant polystyrene material, which is prepared by modifying polystyrene and polypropylene with an oil-based compatibilizer and an additive; the density of the modified heat-resistant polystyrene material is 1.056 g / cm 3 , and the melt index of the modified heat-resistant polystyrene material at 230 °C and 2.16 kg is 5.8 g / 10 min; the tensile strength of the modified heat-resistant polystyrene material is 26.5 MPa, the elongation at break is 45.3%, the flexural strength is 43.9 MPa, the flexural modulus is 1688 MPa, the Izod notched impact strength is 295 J / m, and the Rockwell hardness is 79.9; the modified heat-resistant polystyrene material has good compatibility; the self-weight deformation amount of the modified heat-resistant polystyrene material after being placed at 120 °C for 3 h is 3 mm.

[0054] In this embodiment, the components and contents in the modified heat-resistant polystyrene material are as follows: Polystyrene: 55 parts by weight, including 50 parts by weight of general polystyrene (GPPS-500N) and 5 parts by weight of high-impact polystyrene (HIPS-8265); Polypropylene: 10 parts by weight, which is copolymerized polypropylene (EP300H); Oil-based compatibilizer: 15 parts by weight, which is oil-based SBS; Toughening agent: 10 parts by weight, which is polyolefin elastomer (POE 875); Reinforcing agent: 10 parts by weight, which is talc powder with a mesh number of 2500; Antioxidant: 0.4 parts by weight, including 0.2 parts by weight of antioxidant 1010 and 0.2 parts by weight of antioxidant 168; Lubricant: 0.3 parts by weight, which is ethylene bisstearamide; Light stabilizer: 0.4 parts by weight, including 0.3 parts by weight of UV-622 and 0.1 parts by weight of UV-234; The melt mass flow rate of the general polystyrene (GPPS-500N) is 5.4 g / min at 5 kg, and the notched Izod impact strength is 1.2 kJ / m 2 , and the tensile strength is 45.8 MPa; The melt index of the high-impact polystyrene (HIPS-8265) is 3.5 g / 10 min at 190 °C and 2.16 kg, the tensile yield strength is 22 MPa, the flexural modulus is 1650 MPa, and the elongation at break is 80%; The density of the copolymerized polypropylene (EP300H) is 0.9 g / cm 3 , the melt mass flow rate is 2.0 g / 10 min, the Rockwell hardness is 90, the flexural modulus is 1080 MPa, and the notched Izod impact strength is 69 J / m; The melt index of the oil-based compatibilizer is 17 g / 10 min at 190 °C and 2.16 kg; The density of the polyolefin elastomer (POE 875) is 0.87 g / cm 3 , the melt mass flow rate is 9.0 g / 10 min, and the tensile modulus is 2550 MPa.

[0055] This embodiment also provides a preparation method of the modified heat-resistant polystyrene material, including the following steps: weighing each component according to the component ratio; Step 1. Prepare the oil-based compatibilizer At room temperature, spray 10 parts by weight of naphthenic oil onto 5 parts by weight of polystyrene-butadiene rubber-polystyrene stirred at 300 rpm for 10 min to prepare the oil-based compatibilizer; Step 2: Add polystyrene, polypropylene, the oil-based compatibilizer, toughening agent, reinforcing agent, antioxidant, lubricant, and light stabilizer into a high-speed mixer and mix them at 350 rpm for 3 min. Then feed the mixed material into the main feeding port of a twin-screw extruder. The processing temperature of the twin-screw extruder is 180 - 200 °C, the screw speed of the twin-screw extruder is 300 rpm, the length-diameter ratio is 40:1, the head temperature is 215 °C, the torque is 55 N·m, the main motor current is 450 A, the melt temperature is 220 °C, and the feeding speed at the main feeding port is 500 kg / h; thus, the modified heat-resistant polystyrene material is prepared.

[0056] Such as Figure 1 This is the infrared spectrum of the modified heat-resistant polystyrene material described in Example 1. As can be seen from the figure, in the Fourier transform infrared spectrum, the modified heat-resistant polystyrene material shows a bending vibration peak of C=C on the benzene ring at 1492.47 ± 0.01 cm -1 and a bending vibration peak of C=C on the benzene ring at 1600.84 ± 0.01 cm -1 ; a stretching vibration peak of -CH2- at 2917.46 ± 0.01 cm -1 and a stretching vibration peak of -CH2- at 2848.78 ± 0.01 cm -1 ; and a bending vibration peak of C-H of butadiene at 965.92 ± 0.01 cm -1 . The displacement of the benzene ring peak in the spectrum may be due to the interaction between the PS segment of the oil-based compatibilizer and the molecular chain of polystyrene, and the displacement or splitting of the CH2 / CH3 peak may be due to the interaction between the butadiene segment of the oil-based compatibilizer and polypropylene.

[0057] Such as Figure 2 This is the self-weight deformation state diagram of the modified heat-resistant polystyrene material described in Example 1. As shown in the figure, after being placed at 120 °C for 3 h, no deformation occurs, indicating good heat resistance.

[0058] Example 2 This example provides a modified heat-resistant polystyrene material, which is prepared by modifying polystyrene and polypropylene with an oil-based compatibilizer and additives; the density of the modified heat-resistant polystyrene material is 1.060 g / cm 3, at 230 °C and 2.16 kg, the melt index of the modified heat-resistant polystyrene material is 5.7 g / 10 min; the tensile strength of the modified heat-resistant polystyrene material is 27.3 MPa, the elongation at break is 27.3%, the flexural strength is 42.31 MPa, the flexural modulus is 1619 MPa, the notched Izod impact strength is 321 J / m, and the Rockwell hardness is 53; the modified heat-resistant polystyrene material has good compatibility; the self-weight deformation of the modified heat-resistant polystyrene material after being placed at 120 °C for 3 h is 4 mm.

[0059] In this embodiment, the components and contents in the modified heat-resistant polystyrene material are as follows: Polystyrene: 55 parts by weight, including 50 parts by weight of general polystyrene (GPPS-500N) and 5 parts by weight of high-impact polystyrene (HIPS-8265); Polypropylene: 10 parts by weight, which is copolymerized polypropylene (EP300H); Oil-based compatibilizer: 15 parts by weight, which is oil-based SBS; Toughening agent: 10 parts by weight, which is high-density polyethylene (HDPE 8008); Reinforcing agent: 10 parts by weight, which is 2500-mesh talcum powder; Antioxidant: 0.4 parts by weight, including 0.2 parts by weight of antioxidant 1010 and 0.2 parts by weight of antioxidant 168; Lubricant: 0.3 parts by weight, which is ethylene bis-stearamide; Light stabilizer: 0.4 parts by weight, including 0.3 parts by weight of UV-622 and 0.1 parts by weight of UV-234; The melt mass flow rate of the general polystyrene (GPPS-500N) is 5.4 g / min at 5 kg, and the notched beam impact strength is 1.2 kJ / m 2 , and the tensile strength is 45.8 MPa; The melt index of the high-impact polystyrene (HIPS-8265) is 3.5 g / 10 min at 190 °C and 2.16 kg, the tensile yield strength is 22 MPa, the flexural modulus is 1650 MPa, and the elongation at break is 80%; The density of the copolymerized polypropylene (EP300H) is 0.9 g / cm 3 , the melt mass flow rate is 2.0 g / 10 min, the Rockwell hardness is 90, the flexural modulus is 1080 MPa, and the notched Izod impact strength is 69 J / m; The melt index of the oil-based compatibilizer at 190 °C and 2.16 kg is 17 g / 10 min; The density of the high-density polyethylene (HDPE 8008) is 0.9566 g / cm³, the melt mass flow rate is 7.3 g / 10 min, and the Izod notched impact strength is 5.8 kJ / m².

[0060] This embodiment also provides a method for preparing the modified heat-resistant polystyrene material, which includes the following steps: weighing each component according to the component ratios; Step 1, preparing an oil-compatibilized agent At room temperature, spray 10 parts by weight of naphthenic oil onto 5 parts by weight of polystyrene-butadiene rubber-polystyrene stirred at 300 rpm for 10 min to prepare the oil-compatibilized agent; Step 2, add polystyrene, polypropylene, the oil-compatibilized agent, toughening agent, reinforcing agent, antioxidant, lubricant, and light stabilizer into a high-speed mixer and mix at 350 rpm for 3 min, and feed the mixed material from the main feeding port of the twin-screw extruder. The processing temperature of the twin-screw extruder is 180 - 200 °C, the screw speed of the twin-screw extruder is 350 rpm, the length-diameter ratio is 52:1, the head temperature is 210 °C, the torque is 55 N·m, the main motor current is 450 A, the melt temperature is 225 °C, and the feeding speed at the main feeding port is 500 kg / h; thus, the modified heat-resistant polystyrene material is prepared.

[0061] Example 3 This embodiment provides a modified heat-resistant polystyrene material, which is prepared by modifying polystyrene and polypropylene with an oil-compatibilized agent and additives; the density of the modified heat-resistant polystyrene material is 1.045 g / cm 3 , and the melt index of the modified heat-resistant polystyrene material at 230 °C and 2.16 kg is 5.8 g / 10 min; the tensile strength of the modified heat-resistant polystyrene material is 22.2 MPa, the elongation at break is 31.4%, the flexural strength is 37.8 MPa, the flexural modulus is 1589 MPa, the Izod notched impact strength is 327 J / m, and the Rockwell hardness is 79.9; the modified heat-resistant polystyrene material has good compatibility; the self-weight deformation of the modified heat-resistant polystyrene material after being placed at 120 °C for 3 h is 5 mm.

[0062] In this embodiment, the components and contents in the modified heat-resistant polystyrene material are as follows: Polystyrene: 55 parts by weight, including 50 parts by weight of general polystyrene (GPPS - 500N) and 5 parts by weight of high-impact polystyrene (HIPS - 8265); Polypropylene: 10 parts by weight, which is copolymer polypropylene (EP300H); Oil-compatibilized agent: 15 parts by weight, which is oilified SEBS; Toughening agent: 10 parts by weight, being polyolefin elastomer (POE 875); Reinforcing agent: 10 parts by weight, being talcum powder with 2500 mesh; Antioxidant: 0.4 parts by weight, including 0.2 parts by weight of antioxidant 1010 and 0.2 parts by weight of antioxidant 168; Lubricant: 0.3 parts by weight, being ethylene bisstearamide; Light stabilizer: 0.4 parts by weight, including 0.3 parts by weight of UV-622 and 0.1 parts by weight of UV-234; The melt mass flow rate of the general polystyrene (GPPS-500N) is 5.4 g / min at 5 kg, and the notched Izod impact strength is 1.2 kJ / m 2 , and the tensile strength is 45.8 MPa; The melt index of the high impact polystyrene (HIPS-8265) is 3.5 g / 10 min at 190 °C and 2.16 kg, the tensile yield strength is 22 MPa, the flexural modulus is 1650 MPa, and the elongation at break is 80%; The density of the copolymerized polypropylene (EP300H) is 0.9 g / cm 3 , the melt mass flow rate is 2.0 g / 10 min, the Rockwell hardness is 90, the flexural modulus is 1080 MPa, and the notched Izod impact strength is 69 J / m; The melt index of the oil-based compatibilizer is 17 g / 10 min at 190 °C and 2.16 kg; The density of the polyolefin elastomer (POE 875) is 0.87 g / cm 3 , the melt mass flow rate is 9.0 g / 10 min, and the tensile modulus is 2550 MPa.

[0063] This embodiment also provides a preparation method of the modified heat-resistant polystyrene material, including the following steps: weighing each component according to the component ratio; Step 1, preparing an oil-based compatibilizer At room temperature, 10 parts by weight of naphthenic oil is sprayed onto 5 parts by weight of hydrogenated styrene-butadiene block copolymer stirred at 300 rpm, and the stirring time is 10 min to prepare an oil-based compatibilizer; Step 2: Add polystyrene, polypropylene, the oil-compatible agent, toughening agent, reinforcing agent, antioxidant, lubricant and light stabilizer into a high-speed mixer and mix at 350 rpm for 3 min. Feed the mixed material into the main feeding port of a twin-screw extruder. The processing temperature of the twin-screw extruder is 180 - 200 °C, the screw speed of the twin-screw extruder is 300 rpm, the length-diameter ratio is 40:1, the head temperature is 215 °C, the torque is 55 N·m, the main motor current is 450 A, the melt temperature is 220 °C, and the feeding speed at the main feeding port is 500 kg / h; thus obtain the modified heat-resistant polystyrene material.

[0064] Comparative Example 1 This comparative example provides a commercial polystyrene material. The density of the commercial polystyrene material is 1.022 g / cm 3 , and the melt index of the commercial polystyrene material at 230 °C and 2.16 kg is 4.2 g / 10 min; the tensile strength of the commercial polystyrene material is 27.9 MPa, the elongation at break is 58%, the flexural strength is 35.7 MPa, the flexural modulus is 1669 MPa, the Izod notched impact strength is 134 J / m, and the Rockwell hardness is 73.

[0065] In this comparative example, the manufacturer of the commercial polystyrene material is Total of France, and the grade is HIPS 8265.

[0066] As Figure 3 is the self-weight deformation state diagram of the commercial polystyrene material in Comparative Example 1. As shown in the figure, after being placed at 120 °C for 3 h, the material is severely deformed and has extremely poor heat resistance.

[0067] Comparative Example 2 This comparative example provides a modified heat-resistant polystyrene material, which is prepared by modifying polystyrene and polypropylene with additives; the density of the modified heat-resistant polystyrene material is 1.075 g / cm 3 , and the melt index of the modified heat-resistant polystyrene material at 230 °C and 2.16 kg is 3.4 g / 10 min; the tensile strength of the modified heat-resistant polystyrene material is 26.6 MPa, the elongation at break is 20.6%, the flexural strength is 48.5 MPa, the flexural modulus is 2029 MPa, the Izod notched impact strength is 98 J / m, and the Rockwell hardness is 91; the compatibility of the modified heat-resistant polystyrene material is poor; the self-weight deformation amount of the modified heat-resistant polystyrene material after being placed at 120 °C for 3 h is 5 mm.

[0068] In this comparative example, the components and contents in the modified heat-resistant polystyrene material are as follows: Polystyrene: 65 parts by weight, including 55 parts by weight of general polystyrene (GPPS-500N) and 10 parts by weight of high impact polystyrene (HIPS-8265); Polypropylene: 15 parts by weight, which is copolymerized polypropylene (EP300H); Toughening agent: 10 parts by weight, which is polyolefin elastomer (POE 875); Reinforcing agent: 10 parts by weight, which is talc powder with 2500 mesh; Antioxidant: 0.4 parts by weight, including 0.2 parts by weight of antioxidant 1010 and 0.2 parts by weight of antioxidant 168; Lubricant: 0.3 parts by weight, which is ethylene bisstearamide; Light stabilizer: 0.4 parts by weight, including 0.3 parts by weight of UV-622 and 0.1 parts by weight of UV-234; The general polystyrene (GPPS-500N) has a melt mass flow rate of 5.4 g / min at 5 kg, a Charpy impact strength of 1.2 kJ / m 2 , and a tensile strength of 45.8 MPa; The high impact polystyrene (HIPS-8265) has a melt index of 3.5 g / 10 min at 190 °C and 2.16 kg, a tensile yield strength of 22 MPa, a flexural modulus of 1650 MPa, and an elongation at break of 80%; The density of the copolymerized polypropylene (EP300H) is 0.9 g / cm 3 , a melt mass flow rate of 2.0 g / 10 min, a Rockwell hardness of 90, a flexural modulus of 1080 MPa, and a notched Izod impact strength of 69 J / m; The density of the polyolefin elastomer (POE 875) is 0.87 g / cm 3 , a melt mass flow rate of 9.0 g / 10 min, and a tensile modulus of 2550 MPa.

[0069] This comparative example also provides a preparation method of the modified heat-resistant polystyrene material, including the following steps: weighing each component according to the component ratio; Adding polystyrene, polypropylene, toughening agent, reinforcing agent, antioxidant, lubricant and light stabilizer into a high-speed mixer and mixing for 3 min at 350 rpm, and feeding the mixed material from the main feeding port of a twin-screw extruder. The processing temperature of the twin-screw extruder is 180-200 °C, the screw speed of the twin-screw extruder is 300 rpm, the length-diameter ratio is 40:1, the head temperature is 215 °C, the torque is 55 N·m, the main motor current is 450 A, the melt temperature is 220 °C, and the feeding speed of the main feeding port is 500 kg / h; thus preparing the modified heat-resistant polystyrene material.

[0070] As Figure 4 Figure 4 This is the state diagram of the modified heat-resistant polystyrene material after bending in Example 1, 2 and Comparative Example 2. As shown in the figure, the material in Example 1 does not show delamination and peeling after bending, only regular creases. Example 2 also only shows regular creases after bending, while the material in Comparative Example 2 shows obvious peeling and irregular delamination after bending.

[0071] Comparative Example 3 This comparative example provides a modified heat-resistant polystyrene material, which is prepared by modifying polystyrene and polypropylene with a compatibilizer and additives; the density of the modified heat-resistant polystyrene material is 1.063 g / cm 3 3 , and the melt index of the modified heat-resistant polystyrene material at 230 °C and 2.16 kg is 4.7 g / 10 min; the tensile strength of the modified heat-resistant polystyrene material is 33 MPa, the elongation at break is 24.7%, the flexural strength is 52.6 MPa, the flexural modulus is 1935 MPa, the Izod notched impact strength is 193 J / m, and the Rockwell hardness is 90; the compatibility of the modified heat-resistant polystyrene material is poor; the self-weight deformation of the modified heat-resistant polystyrene material after being placed at 120 °C for 3 h is 5 mm.

[0072]

[0072] In this comparative example, the components and contents in the modified heat-resistant polystyrene material are as follows: Polystyrene: 55 parts by weight, including 50 parts by weight of general polystyrene (GPPS-500N) and 5 parts by weight of high-impact polystyrene (HIPS-8265); Polypropylene: 10 parts by weight, which is copolymerized polypropylene (EP300H); Compatibilizer: 15 parts by weight, which is SBS; Toughening agent: 10 parts by weight, which is polyolefin elastomer (POE 875); Reinforcing agent: 10 parts by weight, which is 2500-mesh talc powder; Antioxidant: 0.4 parts by weight, including 0.2 parts by weight of antioxidant 1010 and 0.2 parts by weight of antioxidant 168; Lubricant: 0.3 parts by weight, which is ethylene bisstearamide; Light stabilizer: 0.4 parts by weight, including 0.3 parts by weight of UV-622 and 0.1 parts by weight of UV-234; The melt mass flow rate of the general polystyrene (GPPS-500N) at 5 kg is 5.4 g / min, and the Charpy impact strength is 1.2 kJ / m 2 2 , and the tensile strength is 45.8 MPa; The high impact polystyrene (HIPS-8265) has a melt index of 3.5 g / 10 min at 190 °C and 2.16 kg, a tensile yield strength of 22 MPa, a flexural modulus of 1650 MPa, and an elongation at break of 80%; The density of the copolymerized polypropylene (EP300H) is 0.9 g / cm 3 , the melt mass flow rate is 2.0 g / 10 min, the Rockwell hardness is 90, the flexural modulus is 1080 MPa, and the Izod notched impact strength is 69 J / m; The density of the polyolefin elastomer (POE 875) is 0.87 g / cm 3 , the melt mass flow rate is 9.0 g / 10 min, and the tensile modulus is 2550 MPa.

[0073] This comparative example also provides a method for preparing the modified heat-resistant polystyrene material, including the following steps: weighing each component according to the component ratio; Adding polystyrene, polypropylene, compatibilizer, toughening agent, reinforcing agent, antioxidant, lubricant, and light stabilizer into a high-speed mixer and mixing for 3 min at 350 rpm, and feeding the mixed material from the main feeding port of a twin-screw extruder. The processing temperature of the twin-screw extruder is 180 - 200 °C, the screw speed of the twin-screw extruder is 300 rpm, the length-diameter ratio is 40:1, the head temperature is 215 °C, the torque is 55 N·m, the main motor current is 450 A, the melt temperature is 220 °C, and the feeding speed of the main feeding port is 500 kg / h; thus obtaining the modified heat-resistant polystyrene material.

[0074] Comparative Example 4 This comparative example provides a modified heat-resistant polystyrene material, which is prepared by modifying polystyrene and polypropylene with a traditional compatibilizer and additives; the density of the modified heat-resistant polystyrene material is 1.046 g / cm 3 , and the melt index of the modified heat-resistant polystyrene material at 230 °C and 2.16 kg is 7.2 g / 10 min; the tensile strength of the modified heat-resistant polystyrene material is 25.9 MPa, the elongation at break is 27.9%, the flexural strength is 36.1 MPa, the flexural modulus is 1591 MPa, the Izod notched impact strength is 77 J / m, and the Rockwell hardness is 79.9; the compatibility of the modified heat-resistant polystyrene material is poor; the self-weight deformation amount of the modified heat-resistant polystyrene material after being placed at 120 °C for 3 h is 6 mm.

[0075] In this comparative example, the components and contents in the modified heat-resistant polystyrene material are: Polystyrene: 55 parts by weight, including 50 parts by weight of general polystyrene (GPPS - 500N) and 5 parts by weight of high - impact polystyrene (HIPS - 8265); Polypropylene: 10 parts by weight, which is copolymer polypropylene (EP300H); Traditional compatibilizer: 15 parts by weight, which is maleic anhydride; Toughening agent: 10 parts by weight, which is polyolefin elastomer (POE 875); Reinforcing agent: 10 parts by weight, which is talc powder with 2500 mesh; Antioxidant: 0.4 parts by weight, including 0.2 parts by weight of antioxidant 1010 and 0.2 parts by weight of antioxidant 168; Lubricant: 0.3 parts by weight, which is ethylene bisstearamide; Light stabilizer: 0.4 parts by weight, including 0.3 parts by weight of UV - 622 and 0.1 parts by weight of UV - 234; The general polystyrene (GPPS - 500N) has a melt mass - flow rate of 5.4 g / min at 5 kg, and a notched Izod impact strength of 1.2 kJ / m 2 , and a tensile strength of 45.8 MPa; The high - impact polystyrene (HIPS - 8265) has a melt index of 3.5 g / 10 min at 190 °C and 2.16 kg, a tensile yield strength of 22 MPa, a flexural modulus of 1650 MPa, and an elongation at break of 80%; The copolymer polypropylene (EP300H) has a density of 0.9 g / cm 3 , a melt mass - flow rate of 2.0 g / 10 min, a Rockwell hardness of 90, a flexural modulus of 1080 MPa, and a notched Izod impact strength of 69 J / m; The polyolefin elastomer (POE 875) has a density of 0.87 g / cm 3 , a melt mass - flow rate of 9.0 g / 10 min, and a tensile modulus of 2550 MPa.

[0076] This comparative example also provides a preparation method of the modified heat - resistant polystyrene material, including the following steps: Weigh each component according to the component ratio; Polystyrene, polypropylene, a traditional compatibilizer, a toughening agent, a reinforcing agent, an antioxidant, a lubricant, and a light stabilizer were added to a high-speed mixer and mixed at 350 rpm for 3 min. The mixed material was fed into the main feeding port of a twin-screw extruder. The processing temperature of the twin-screw extruder was 180 - 200 °C, the screw speed of the twin-screw extruder was 300 rpm, the length-diameter ratio was 40:1, the head temperature was 215 °C, the torque was 55 N·m, the main motor current was 450 A, the melt temperature was 220 °C, and the feeding speed at the main feeding port was 500 kg / h; the modified heat-resistant polystyrene material was prepared.

[0077] Table 1 shows the components and contents of the modified heat-resistant polystyrene material in the present invention

[0078] Table 2 shows the properties of the materials in the present invention

[0079] As shown in Tables 1 and 2, the mechanical comprehensive properties of the modified heat-resistant polystyrene materials in Examples 1 - 3 of the present invention are strong. In particular, the notched Izod impact strength is high, and the compatibility between polystyrene and polypropylene is also good, and the heat resistance is also good. Comparative Example 1 is a common high-impact polystyrene on the market. However, the impact resistance of the modified heat-resistant polystyrene material in the present invention is still higher than that of Comparative Example 1, and other comprehensive properties are also much higher than those of Comparative Example 1. Under heat-resistant conditions, the modified heat-resistant polystyrene material in the present invention does not deform, while the conventional high-impact polystyrene in Comparative Example 1 will undergo serious deformation; in Comparative Example 2, no compatibilizer was added, the melt index of the material decreased, and the notched Izod impact strength also decreased significantly; in Comparative Example 3, the compatibilizer was not oiled, and its compatibility with polystyrene and polypropylene was poor, and the notched Izod impact strength decreased, unable to meet the conventional use requirements; in Comparative Example 4, a traditional maleic anhydride compatibilizer was used, and its compatibilization effect was quite poor, the melt index increased, and the deformation amount at high temperature also increased.

[0080] It should be emphasized that the temperature range of the processing temperature of the materials in the present invention is not limited to a certain fixed range, and the parameter settings of the twin-screw extruder can be adjusted according to the actual situation. Parameters such as the feeding amount and the length-diameter ratio can be adjusted according to the model of the twin-screw extruder.

[0081] From the above, it can be seen that the modified heat-resistant polystyrene material of the present invention has a very wide range of uses, low cost, and extremely high market prospects.

[0082] The above are only the preferred embodiments of the present invention, and do not constitute any other form of limitation to the present invention. Any modification or equivalent change made according to the technical essence of the present invention still belongs to the scope protected by the present invention.

Claims

1. A modified heat-resistant polystyrene material, characterized in that, The modified heat-resistant polystyrene material is prepared by modifying polystyrene and polypropylene with an oil-based compatibilizer and additives; the density of the modified heat-resistant polystyrene material is 1.04 - 1.06 g / cm 3 , and the melt index of the modified heat-resistant polystyrene material at 230 °C and 2.16 kg is 5.5 - 14 g / 10 min; the tensile strength of the modified heat-resistant polystyrene material is 21 - 28 MPa, the elongation at break is 30 - 50%, the flexural strength is 35 - 45 MPa, the flexural modulus is 1600 - 1700 MPa, the Izod notched impact strength is 290 - 330 J / m, and the Rockwell hardness is 50 - 80; the modified heat-resistant polystyrene material has good compatibility; the self-weight deformation of the modified heat-resistant polystyrene material after being placed at 120 °C for 3 h is 3 - 5 mm.

2. The modified heat-resistant polystyrene material according to claim 1, characterized in that, The auxiliary agents include a toughening agent, a reinforcing agent, an antioxidant, a lubricant, and a light stabilizer.

3. The modified heat-resistant polystyrene material according to claim 2, characterized in that, The components and contents in the modified heat-resistant polystyrene material are as follows: Polystyrene: 30 - 80 parts by weight; Polypropylene: 5 - 20 parts by weight; Oil-based compatibilizer: 10 - 20 parts by weight; Toughening agent: 5 - 20 parts by weight; Reinforcing agent: 5 - 20 parts by weight; Antioxidant: 0.1 - 1 part by weight; Lubricant: 0.1 - 1 part by weight; Light stabilizer: 0.01 - 1 part by weight.

4. The modified heat-resistant polystyrene material according to claim 1, wherein The oil-based compatibilizer is prepared by spraying and modifying an oil on a conventional compatibilizer under stirring at room temperature.

5. A method for preparing the modified heat-resistant polystyrene material according to any one of claims 1-4, characterized in that, It includes the following steps: Weigh each component according to the component ratio; Step 1: Prepare the oil-based compatibilizer At room temperature, spray the modified oil onto the stirred conventional compatibilizer to prepare the oil-based compatibilizer; Step 2: Add polystyrene, polypropylene, the oil-based compatibilizer, toughening agent, reinforcing agent, antioxidant, lubricant, and light stabilizer into a high-speed mixer for mixing, and feed the mixed material through the main feeding port of a twin-screw extruder to prepare the modified heat-resistant polystyrene material.

6. The preparation method according to claim 5, characterized in that, The modified oil in Step 1 includes one or both of paraffin oil and naphthenic oil.

7. The preparation method according to claim 5, characterized in that, The conventional compatibilizer in Step 1 includes one or several of polystyrene-butadiene rubber-polystyrene, hydrogenated styrene-butadiene block copolymer, ethylene-vinyl acetate copolymer, ethylene propylene diene monomer, styrene-isoprene-styrene block copolymer, chlorinated polyethylene, and polystyrene-butadiene copolymer.

8. The preparation method according to claim 5, characterized in that, The polystyrene in Step 2 includes one or both of general polystyrene and high impact polystyrene.

9. The preparation method according to claim 5, characterized in that, The polypropylene in Step 2 includes one or both of homopolypropylene and copolymerized polypropylene.

10. An automobile or electrical appliance packaging, characterized in that, The raw material for the automotive or electrical appliance packaging includes the modified heat-resistant polystyrene material according to any one of claims 1 - 4.

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