JP4714821B2 - Polymer composite material and manufacturing method thereof - Google Patents

Description

  The present invention relates to a polymer composite material and a method for producing the same.

  In recent years, from the viewpoints of global environment conservation, fossil resource saving, energy saving, etc., development of high-performance and functional technology of general-purpose polymer materials (plastics) with excellent cost performance and alternative technology of the current melt blend compound technology has been developed. It is desired. For this purpose, it is possible to prepare a material that exceeds the physical properties of each synthetic polymer by blending two or more types of polymers with different properties, and a block copolymer in which different types of polymers are linked by covalent bonds. It is well known that it is more economical and more efficient than newly developing a single material, such as a polymer or a graft copolymer.

  However, the polymers have different cohesive energy densities and are generally difficult to compatibilize (molecular dispersion that dissolves in molecular order). For example, isotactic polypropylene (PP) and polymethyl methacrylate (PMMA), which are typical materials for general-purpose plastics, are prepared by reprecipitation from a homogeneous solution using a common organic solvent and blended to produce a macrophase separation (micrometer order). Sea-island structure formation: compatibilization).

  An object of the present invention is to provide a novel polymer composite material, particularly an incompatible crystalline polymer / non-crystalline polymer nano-dispersed system. Furthermore, it aims at providing the manufacturing method.

  The inventors of the present invention have intensively studied to solve such a problem. Under the condition that the crystal structure of the crystalline polymer does not collapse, an amorphous polymer monomer that does not normally mix thermodynamically is used as the crystalline polymer substrate. By impregnating and polymerizing the impregnated monomer in the substrate, it is possible to obtain an incompatible crystalline polymer / non-crystalline polymer nano-dispersion system that is a polymer composite material that exhibits completely new physical properties. And the present invention was completed based on this finding.

  The polymer composite material according to the present invention is a composite composed of an amorphous polymer and a crystalline polymer that do not mix thermodynamically, and the amorphous polymer is an amorphous layer (sphere) of a crystalline polymer. It is a nanocomposite characterized in that a co-continuous interpenetrating network (IPN) is formed by being dispersed on the order of nanometers between intercrystals, fibril microvoids, and lamellar structures.

  In the present invention, the amorphous polymer is a PMMA-based, acrylic-based, polystyrene-based, polyvinyl chloride-based, polyvinyl acetate-based, or polybutadiene-based polymer, and the crystalline polymer is a low-density and high-density polyethylene (LDPE). , HDPE), syndiotactic polystyrene (sPS), polypropylene (PP), polyethylene terephthalate (PET), polycarbonate (PC), polyamide (PA), and polyimide (PI).

  Furthermore, the present invention relates to a method for producing the above novel polymer composite, and a monomer of an amorphous polymer that does not normally mix thermodynamically under the condition that the crystal structure of the crystalline polymer does not collapse. It is characterized by impregnating a crystalline polymer substrate and polymerizing the impregnated monomer in the substrate.

  In the present invention, the crystalline polymer is any of LDPE, HDPE, sPS, PP, PET, and PC, the amorphous polymer is a PMMA polymer, and the amorphous polymer is in a supercritical fluid. The monomer is impregnated and polymerized.

  Furthermore, the present invention is characterized in that the supercritical fluid is supercritical carbon dioxide.

  In the production method according to the present invention, a crystalline polymer substrate is impregnated with a monomer of an amorphous polymer that does not normally mix thermodynamically under a condition that the crystal structure of the crystalline polymer does not collapse. The monomer is polymerized in a substrate. Therefore, the polymer composite material according to the present invention is a composite composed of an amorphous polymer and a crystalline polymer that do not mix thermodynamically, and the amorphous polymer is an amorphous layer of a crystalline polymer. It is a nanocomposite characterized in that it is dispersed in nanometer order (all between spherulites, fibril microvoids, and lamella structures) to form a co-continuous phase interpenetrating network (IPN).

(Polymer composite material)
The polymer composite material of the present invention is a composite composed of two or more kinds of polymers. These polymers are polymers that do not mix thermodynamically. In the conventional method, such a polymer has a so-called macro-separated structure (for example, a sea-island structure of micron order) even if it is mixed in a solution and reprecipitated or melt-blended. The polymer material of the present invention is a composite having a structure in which two or more kinds of polymers are mixed on the nano order. In particular, the polymer composite material of the present invention is a composite comprising a crystalline polymer and an amorphous polymer. More specifically, the polymer composite material according to the present invention is a composite composed of an amorphous polymer and a crystalline polymer that do not mix thermodynamically, and the amorphous polymer is a crystalline polymer. It is a nanocomposite characterized in that it forms a co-continuous interpenetrating network (IPN) dispersed in amorphous layers (all between spherulites, fibril microvoids, and lamellar structures) in nanometer order. .

  Here, the amorphous polymer that can be used in the present invention is not particularly limited and may be any known amorphous polymer having desired physical properties. Specific examples include polymers such as PMMA, polymethyl acrylate (PMA), polystyrene (PS), polyvinyl chloride (PVC), polyvinyl acetate (PVAC), and polybutadiene.

  The crystalline polymer that can be used in the present invention is not particularly limited, and various polymers having a known crystallinity can be selected. Specific examples include polyethylene, polystyrene, polypropylene, polyester, polyamino, and polycarbonate. Particularly known low-density polyethylene (LDPE), high-density polyethylene (HDPE), syndiotactic polystyrene, polypropylene (PP), polyester (PET), polyamino (PA), polyimide (PI), and polycarbonate (PC). . A crystalline polymer has a crystalline layer and an amorphous layer, and its crystallinity and crystal structure can be determined by various known methods. In addition, the crystalline polymer has a folded molecular chain that forms a lamella structure on the order of nanometers. The lamella structure forms a lamellar repeating structure with amorphous tie molecules (amorphous layers), and these become fibrils. , Has a hierarchical structure that grows into spherulites on the order of several μm to several mm. In the polymer composite material according to the present invention, an amorphous polymer is dispersed in a nanometer order between the spherulites of the crystalline polymer, the microvoids of the fibrils, and the lamellar structure, and a co-continuous phase interpenetrating network (IPN ) Structure. Therefore, the polymer composite material of the present invention is characterized in that the lamellar repeating structure of the crystalline polymer is changed.

  Furthermore, since the non-crystalline polymer is dispersed in nanometer order between the spherulites of the crystalline polymer, the microvoids of the fibrils, and the lamellar structure, it has a co-continuous phase interpenetrating network (IPN) structure. The polymer composite material is characterized in that it exhibits a completely different morphology from that of the amorphous polymer and the crystalline polymer itself, and also exhibits thermodynamic and further mechanical properties. Specifically, it has unique values for crystal melting behavior, thermal decomposition behavior, Tg, storage elastic modulus and the like.

(Production method)
The polymer composite material of the present invention described above impregnates a crystalline polymer substrate with a monomer of an amorphous polymer that does not normally mix thermodynamically under conditions where the crystal structure of the crystalline polymer does not collapse, The impregnated monomer is polymerized in a substrate.

  Here, the conditions under which the crystal structure of the crystalline polymer does not collapse is not particularly limited as long as the crystalline polymer is used as a substrate and the crystalline structure does not collapse due to thermal action or interaction with a solvent. . It is preferable that the amorphous polymer monomer is dissolved in a necessary amount and can be polymerized as it is (in-situ) without changing the shape of the crystalline polymer substrate.

  The present inventor has found that various supercritical fluids can be used to realize such special conditions. The use of supercritical carbon dioxide is particularly preferable. In this supercritical fluid, the crystalline polymer as a substrate can be impregnated with a sufficient amount of amorphous polymer monomer without changing its shape greatly (equilibrium). Further, during the polymerization reaction after the impregnation, as the amorphous polymer is formed in the crystalline polymer, the concentration of the amorphous polymer monomer in the crystalline polymer is decreased and the equilibrium is shifted. The monomer further moves into the crystalline polymer, and the polymerization reaction can proceed.

  Specifically, the crystalline polymer usable in the present invention is not particularly limited as long as it can be used as a substrate. Various known crystalline polymers having desired characteristics and functions can be used, and examples thereof include LDPE, HDPE, sPS, PP, PET, PC, PA, and PIT. Here, the crystallinity of LDPE, HDPE, and sPS can be used if known, and if not known, an appropriate measuring method (wide angle X-ray diffraction (WAXD), differential scanning calorimeter (DSC), etc.) Thus, the crystallinity can be known. LDPE and HDPE are commercially available in various constituent components, abundance ratios, and molecular weights (molecular weight distribution), and these can be preferably used. Various sPS are commercially available and can be used. Further, for example, those produced according to the methods described in JP-A Nos. 62-187708 and 63-191811 may be used. Specifically, it can be obtained by polymerizing various styrene monomers in the presence of an inert hydrocarbon solvent or in the absence of a solvent, using a titanium compound and a condensation product of water and trialkylaluminum as a catalyst.

  Moreover, there is no restriction | limiting in particular also about the shape in the case of using these as a substrate. Examples include films, plates, pellets, granules, or molded articles having various shapes. There is no restriction | limiting in particular also about the method of shape | molding in this shape, A normally well-known method can be used preferably.

  The amorphous polymer used in the production method of the present invention is the one in which the above crystalline polymer substrate is first impregnated in a monomer state. Therefore, the monomer is not particularly limited as long as it is a monomer in which a concentration gradient is achieved outside and inside the substrate in a supercritical fluid. Various polymer monomers can be selected to exhibit desired properties and functions. Specifically, PMMA system, PS system, and PMA system are mentioned. In particular, in the present invention, it is preferable to use a PMMA system in combination with a PE system, a PS system, or a PP system.

  There are no particular limitations on the impregnation conditions, and it is possible to leave it at an appropriate temperature for an appropriate time until sufficient monomers are impregnated in the supercritical fluid to be used. Here, the impregnation temperature also depends on supercritical conditions, and when a polymerization initiator is included in the subsequent polymerization reaction, a temperature lower by several tens of degrees than the polymerization start temperature is preferable. Specifically, when carbon dioxide in a critical state is used, the impregnation pressure is 1-40 MPa, the temperature is −50 to 150 ° C., and the time is in the range of 0.1 to 96 hours. The degree of impregnation can be easily known by removing the substrate after the impregnation and measuring the weight increase. Depending on the impregnation conditions, the weight increase can be freely set in the range of several wt% to several hundred wt%.

  In the present invention, preferably, after impregnation, the impregnated monomer is polymerized as it is (in-situ reaction). The polymerization reaction conditions can be appropriately selected depending on the supercritical fluid used, the type of amorphous polymer monomer, and the type of polymerization reaction. A radical polymerization reaction that can be initiated at a specific temperature is preferred. The radical polymerization reaction initiator used for the radical polymerization reaction is preferably one that starts at a temperature several tens of degrees higher than the temperature used in the impregnation described above. Specific examples include α, α'-azobisisobutyronitrile (AIBN), benzoyl peroxide (BPO), and the like. When the supercritical fluid is carbon dioxide and the monomer is methyl methacrylic acid (MMA), the polymerization initiator is preferably AIBN that can be used at about 80 ° C. There is no restriction | limiting in particular also about polymerization reaction time, It can select suitably and can be stopped by addition of a polymerization terminator, cooling of a reaction system, etc. if necessary. Further, after removal from the reaction apparatus, it is necessary to remove the polymer produced by the polymerization reaction outside the substrate, but washing with an appropriate solvent is preferred.

  The obtained polymer composite may change due to the increased amorphous polymer, although the shape of the substrate is almost maintained. For example, when a square film shape is used as a substrate, the shape of the composite obtained is a square but a larger square.

  Examples will be described in more detail below.

(Composite material of PMMA, HDPE and LDPE)
Measuring device: EXSTAR6000 series TG / DTA6200 manufactured by Seiko Denshi Kogyo Co., Ltd. and dynamic viscoelastic DVA-220 manufactured by Acty Measurement Control Co., Ltd. were used for measurement of TG and DMA, respectively. INTERSCO IM-20 was used for the tensile test. The SAXS measurement was performed using a high energy accelerator research organization Photon Factory.

  Reactor: Two types of supercritical reactors manufactured by Pressure Glass Industry Co., Ltd., having a maximum operating temperature and pressure of 200 ° C. and 12 MPa and a maximum operating temperature and pressure of 400 ° C. and 40 MPa were used.

Preparation of substrate: Commercially available low density polyethylene (LDPE, molecular weight (Mn) 1.4 × 10 ⁴ , crystallinity 37%) pellets and high density polyethylene (HDPE, molecular weight (Mn) 1.5 × manufactured by Nippon Polyolefin Co., Ltd. 10 ⁵ , degree of crystallinity 71%) Each of the pellets was sandwiched between polyethylene terephthalate sheets, dissolved in a heat press machine for 10 to 15 minutes, and then heat pressed at 180 ° C. and 30 MPa for 30 minutes to form a sheet, This was sandwiched between cooling copper plates and quenched. Thereafter, the sheet was cut into 20 mm × 20 mm × 0.5 mm to obtain a substrate (about 0.2 g). Such substrates were impregnated and polymerized under the conditions summarized in Tables 1 and 2.

  Impregnation conditions: 5 g of methyl methacrylate (MMA), α, α'-azobisisobutyronitrile (AIBN) in a predetermined amount shown in Tables 1 and 2 were sampled and charged into the reactor together with the substrate. Carbon dioxide was supplied into the post-reactor under the conditions shown in Tables 1 and 2, and impregnation was performed at 40 ° C. and 7 MPa for 1 hour and 24 hours.

  Polymerization conditions: After impregnation, as shown in the polymerization conditions of Tables 1 and 2, the temperature was kept at 80 ° C. for a predetermined time under a predetermined pressure. After completion of the reaction, the reaction cell was rapidly cooled to remove carbon dioxide in the cell out of the system. In order to remove the polymer adhering to the surface of the substrate, 200 ml of acetone was refluxed for 1 hour using a Soxhlet refluxer, and the polymer adhering to the surface of the resulting polymer composite material was dissolved and washed. Thereafter, the substrate was vacuum-heated and dried at 50 ° C. until the substrate became a constant weight. The dissolved polymer was re-precipitated with hexane in the same manner as the polymer in the reaction cell, separated and recovered, and then recovered by vacuum drying at 50 ° C.

  Tables 1 and 2 also summarize the weight increase rates of the obtained polymer composite materials.

  Results: FIG. 1 and Table 3 show the results of differential scanning calorimetry (DSC) measurement of the obtained polymer composite material. Here, FIG. 1 plots the crystal melting enthalpy of LDPE and HDPE against the weight fraction of LDPE and HDPE. It can be seen that as the MMA content in the polymer composite increases, the crystal melting enthalpy decreases almost linearly. Table 1 summarizes the melting point, crystal melting enthalpy, and crystallinity of the polymer composite with respect to the weight fraction of LDPE and HDPE.

  2 and 3, HDPE, LDPE and PMMA composites (represented as HDPE / PMMA (number)% hybrid, LDPE / PMMA (number)% hybrid, respectively). Here, PMMA contained in the composite The results of thermogravimetric analysis (TG) of (% by weight) (%) are shown. It can be seen that the thermal decomposition start temperature gradually decreases for both HDPE and LDPE due to an increase in PMMA, and the thermal decomposition rate changes greatly with an increase in the PMMA composition.

  4 and 5 show DMA curves of complexes with HDPE and LDPE, respectively.

It can be seen that HDPE has a clear difference from the HDPE / PMMA organic solvent blend obtained by blending HDPE and PMMA using an organic solvent. This result is considered to be due to the plasticizing effect of the PMMA chain in the composite of the present invention (scCO ₂ system hybrid). On the other hand, when the heat treatment was performed at 170 ° C. for 1 minute, a curve almost similar to that of the HDPE / PMMA organic solvent blend was obtained, and the plasticizing effect was not observed in the composite of the present invention.

  In LDPE / PMMA hybrid, it can be seen that there is a difference in storage elastic modulus (E ′) depending on the impregnation time (1 h and 24 h impregnation). It can be seen that also in LDPE / PMMA hybrid tan δ, Tg moves to the higher temperature side than the Tg of homo PMMA chain. It can also be seen that it is also significantly different from HDPE / PMMA organic solvent blend.

6, 7, 8, 9 and 10, plots of the Lorentz correction Iq ² obtained by SAXS measurement with respect to q (scattering vector) are shown. Here, FIGS. 6 and 7 compare the heating of the pure substance HDPE, the organic solvent system blend, the scCO ₂ system hybrid, and the scCO ₂ system hybrid, respectively. The scCO ₂ hybrid showed a difference in scattering peak as compared with HDPE, the lamellar repeat structure changed, and a difference in its long period appeared. In particular, those prepared with scCO ₂ system hybrid AIBN 0.1 mol% showed a tendency that the peak derived from the long period decreased and disappeared. This is considered to be due to the result that PMMA was generated in all amorphous phases between the lamellar crystal layers, and monomer MMA was more uniformly impregnated and polymerized.

7 and 8 a comparison of post scCO ₂ system hybrid and scCO ₂ based hybrid heating in HDPE system (annealing), appears a change in the peak top from lamellar repeat length cycle, the long period is changed by heating In the scCO ₂ hybrid, it is considered that PMMA produced in the amorphous layer was somewhat separated and decomposed by heat.

FIG. 9 is a comparison with LDPE, LDPE / PMMA organic solvent blend, scCO ₂ hybrid. The scCO ₂ hybrid shows that the peak derived from the long period of the lamellar repeating structure almost disappears, indicating that PMMA was uniformly generated in all the amorphous phases between the lamellar crystal layers.

FIG. 10 is a comparison between scCO ₂ -based hybrid and scCO ₂ -based hybrid at 5, _20, and 40 minutes after heating. Depending on the heating time, a peak derived from the long period of the lamellar repetitive structure can be observed somewhat, but it is a very weak peak compared to the organic solvent blend, and the scCO ₂ hybrid is a condition under which the LDPE crystal melts. It is considered that the structure is hardly separated and disintegrated even when heated at.

  FIG. 11 is a TEM photograph of a thin piece of HDPE / PMMA 100% organic solvent blend (cryomicrotome method). The white part is a void, the area around it that appears black is PMMA (island), and the sea phase is HDPE. As described above, the TEM photograph has macro phase separation on the order of microns.

  FIG. 12 is a TEM photograph (room temperature microtome method) impregnated with HDPE / PMMA 77.8% hybrid 24h. The white and black streaks appear clearly, but this is due to microtome chattering. However, since no macrophase separation can be confirmed as compared with the organic solvent blend, it is considered that PMMA is uniformly dispersed on the nanometer order.

  FIG. 13 is a TEM photograph (room temperature microtome method) after annealing (170 ° C., 1 minute) impregnated with HDPE / PMMA 87.3% hybrid 24h. Even with 1-minute annealing, the sea-island structure on the order of microns cannot be confirmed, and no macrophase separation has occurred, confirming that a uniform dispersed state is maintained.

  FIG. 14 is a TEM photograph (cryomicrotome method) of LDPE / PMMA 100% organic solvent blend. The white portions are voids, and the LDPE is relatively soft, so that the hard PMMA slips out and becomes a hole during cutting. It was confirmed that the morphology formed a micro phase separation structure of micron order (island was PMMA, sea was LDPE).

  FIG. 15 is a TEM photograph (room temperature microtome method) of LDPE / PMMA 82.2% hybrid 24h impregnation. The macrophase separation structure cannot be confirmed at all, indicating that PMMA is uniformly dispersed by LDPE.

  FIG. 16 is a TEM photograph (room temperature microtome) of LDPE / PMMA 87.3% hybrid 24h-impregnated annealing at 170 ° C. for 20 minutes. Even when the heating time is 20 minutes, macro-phase separation on the micron order is not confirmed, and it is considered that the formed nanometer order uniform dispersion structure is maintained.

(Composite material of PMMA and sPS)
The reagent used for the reaction was purified as follows.

  As the syndiotactic polystyrene (sPS), a sheet shape made by Idemitsu Co., Ltd. was used. As α, α′-azobisisobutyronitrile (AIBN), AIBN produced by Kanto Chemical Co., Ltd. (Koshi Special Grade) was purified by methanol. Methyl methacrylate (MMA) manufactured by Wako Pure Chemical Industries, Ltd. (98.0%) was used.

  The same reactor as that used in Example 1 was used (Jasco SCF-Get (supercritical carbon dioxide fluid injection pump), SCF-Sro (air thermostat)).

  Preparation of substrate: sPS sheet was cut into 20 × 20 × 0.3 mm and used.

  Impregnation conditions: 2 g of methyl methacrylate (MMA), 1 mol% (0.0328 g) of α, α′-azobisisobutyronitrile (AIBN) was collected and charged into the reactor together with the substrate. Carbon dioxide was supplied into the post-reactor under the conditions shown in Table 4 and impregnated at 40 ° C. and the pressure shown in Table 4 for 1 hour.

  Polymerization conditions: The post-temperature was set to 80 ° C. and reacted for 24 hours under a predetermined pressure. After completion of the reaction, the reaction cell was rapidly cooled to remove carbon dioxide in the cell out of the system. In order to remove the polymer adhering to the substrate surface, 200 ml of acetone was refluxed for 1 hour using a Soxhlet refluxer, and the polymer adhering to the obtained polymer composite material surface was dissolved and washed. Thereafter, the substrate was vacuum-heated and dried at 50 ° C. until the substrate became a constant weight. The dissolved polymer was re-precipitated with hexane in the same manner as the polymer in the reaction cell, separated and recovered, and then recovered by vacuum drying at 50 ° C.

  Table 4 also summarizes the weight increase rate of the obtained polymer composite material.

A blend obtained by dissolving and precipitating sPS and PMMA in an organic solvent for the purpose of comparison with the polymer composite produced above (hereinafter referred to as “sPS / PMMA critical blend”). sPS / PMMA organic solvent blend "), and the results of transmission electron microscope (TEM) observation of those obtained by the annealing treatment are shown in FIGS. FIG. 17 shows a TEM photograph of the sPS substrate itself. FIG. 18 shows a TEM photograph of the organic solvent blend, and it can be seen that macrophase separation occurs and a large sea-island morphology is formed as conventionally known. Compared to this, as shown in FIGS. 19 and 20, the sPS / PMMA supercritical blend is characterized in that no clear morphology such as a micron-order sea-island structure is observed in the observation magnification. This result means that the sPS / PMMA supercritical blend rather forms a nanometer-order microphase separation morphology. Further, FIG. 21 shows a TEM photograph after annealing the sPS / PMMA supercritical blend for 1 minute at a temperature of 300 ° C. at which the crystals of sPS melt. Certainly, the annealing treatment forms a homology of the sea-island structure, but it can be seen that the sea-island structure is much smaller in size than that found in the organic solvent blend. This result means that the structure of the supercritical blend is more stable to heat than the blend with the organic solvent.

  FIG. 22 shows the analysis result by TG. It can be seen that in the organic solvent blend, sPS is decomposed after PMMA is decomposed. On the other hand, in the supercritical blend, it can be seen that all PMMA decomposes at around 340 ° C. This result means that since the PMMA polymer molecule strongly acts on the sPS polymer molecule, thermal decomposition reaction cannot occur independently of each other. This means that the PMMA polymer molecule strongly acts on the amorphous part of the sPS polymer molecule, as strongly suggested by the SAXS measurement results below.

  23 and 24 show the results of analysis by DMA. In the sPS / PMMA supercritical blend shown in FIG. 23, it can be seen that the tan δ peak (Tg) of sPS itself is around 110 ° C., and the tan δ peak of PMMA itself is around 140 ° C. On the other hand, in the supercritical blend, it can be seen that the tan δ peak is shifted to the low temperature side as a whole (around 90 to 120 ° C. depending on the PMMA content).

  Looking further at E ', sPS decreases once and then increases again. This is probably because rearrangement occurred in the structure of sPS. On the other hand, it can be seen that in the supercritical blend, the higher the PMMA content, the higher the temperature at which this rearrangement occurs, and the lower the return width. It hardly returns at a weight increase rate of 300 wt%. FIG. 24 shows the result of annealing the sPS / PMMA supercritical blend. Since rearrangement has already progressed by heating to 190 ° C., the peak is not observed at E ′, but it is the same as before annealing. It can be seen that the strength of is maintained. This result is considered that the PMMA polymer molecule acts strongly on the amorphous region of the sPS polymer molecule and inhibits the rearrangement of sPS, as strongly suggested from the measurement result of SAXS. Interestingly, this phenomenon is recognized as being effective even above the decomposition temperature of PMMA itself.

25 to 27 show small angle X-ray scattering (SAXS) curves for crystal structure analysis. In sPS itself, a long period of a lamellar repeating structure was not observed. In the organic solvent blend, since the sea island structure was formed, the scattering intensity increased as the angle decreased. On the other hand, in the supercritical blend (65 wt%), the peak is observed at q = 0.04Å ⁻¹ (long period 16 nm). This result indicates that PMMA penetrates (blends) into a specific amorphous region in sPS. As a result, it is considered that the space between the lamellar repeating structures is widened. Further, when the amount of impregnation with PMMA increases, the peak shifts to q = 0.018 ^-1 (long period 35 nm). This is considered to be due to the PMMA impregnated in the amorphous layer between the lamellar repeating structures in sPS further expanding the amorphous region and the space between the lamellar repeating structures. When the supercritical blend is annealed (300 ° C., 1 min), this long-period peak almost disappears and a large peak is observed on the small angle side. This result is considered to have formed a macrophase separation structure by annealing at 300 ° C., and agrees with the observation result of TEM described above. On the other hand, as shown in FIGS. 26 and 27, in the case where the annealing treatment (65 to 97 wt%, 1 min, 5 min, 10 min) is performed at a temperature of 190 ° C. at which the sPS crystal does not melt, the long period peak shifts to the high temperature side. This is completely different from the annealing treatment at 300 ° C. and the organic solvent blend. This is because even when annealed at 190 ° C., the nanometer-order microphase separation structure formed with the supercritical blend hardly collapses, the micron-order sea-island structure does not form, and is formed with the supercritical blend. It is thought that it retains the morphology.

  FIG. 28 shows the result of the tensile test. Since both sPS itself and PMMA itself are hard materials, it is difficult to compare supercritical blends. However, since PMMA has a slightly higher elongation, sPS and PMMA are almost 1: 1 in supercritical blends. And was observed just between PMMA. Those that normally form macro-phase separation are expected to concentrate stress at the interface and have a lower physical property than the substrate or impregnated material, so supercritical blends form a micro-phase separation structure and cause strong entanglement. It is thought that.

(Composite material of PMMA and PP)
Preparation of substrate: Isotactic polypropylene (iPP) used in the reaction was prepared by dissolving Chisso Corporation pellets at 190 ° C. for 15 minutes in a heat press, pressurizing at 20 MPa for 20 minutes, and then cooling to PP substrate (sheet) Is cut into 20 × 20 × 0.5 mm).

  The same reagents as used in Examples 1 and 2 were used.

  The same reactor as that used in Example 1 was used (Jasco SCF-Get (supercritical carbon dioxide fluid injection pump), SCF-Sro (air thermostat)).

Impregnation conditions: 2 g of methyl methacrylate (MMA), 1 mol% (0.0328 g) of α, α′-azobisisobutyronitrile (AIBN) was collected and charged into the reactor together with the PP substrate. Carbon dioxide was supplied and impregnated into the reactor under the conditions described in the following table. Further, the pressure of scCO _{2 for} the impregnation treatment was 6.3 MPa and 6.8 MPa for 5 minutes impregnation and 1 hour impregnation, respectively.

  Polymerization conditions: The post-temperature was set to 80 ° C. and reacted for 24 hours under a predetermined pressure. The polymerization pressure was 9.1 MPa for the polymerization reaction after 5 minutes of impregnation and 9.4 MPa for the polymerization reaction after 1 hour of impregnation. After completion of the reaction, the reaction cell was rapidly cooled to remove carbon dioxide in the cell out of the system. In order to remove the polymer adhering to the substrate surface, the polymer adhering to the polymer composite surface obtained by washing twice with hot acetone was dissolved and washed. Thereafter, the substrate was vacuum-heated and dried at 50 ° C. until the substrate became a constant weight. The dissolved polymer was re-precipitated with hexane in the same manner as the polymer in the reaction cell, separated and recovered, and then recovered by vacuum drying at 50 ° C.

FIG. 29 shows a plot of Lorentz corrected scattering intensity (I (q) q ² ) obtained by SAXS measurement of scCO ₂ Blend (impregnation condition 35 ° C., 5 min) against q (scattering vector). The numerical values in the figure represent the weight ratio of each component in the blend. In the PP substrate, the first peak (q = 0.43), the second peak (q = 0.88) and the third peak (q = 1.28) are observed, and the PP crystal layer (PPc) -PP amorphous layer The average value of the long cycle of (PPa) was about 14.3 nm.

  In Organic Solvent Blend prepared from a homogeneous solution of PP and PMMA, only PPc-PPa structure scattering peaks were observed. This is because PP and PMMA formed a sea / island structure of micrometer order. Conceivable.

On the other hand, with scCO ₂ Blend, as the PMMA content increases, the PPc-PPa scattering peak observed with PP alone shifts to the wide-angle side, the long period slightly shortens, and at the same time a shoulder appears on the small-angle side, At a weight increase rate of 39 wt%, a peak corresponding to a new repetitive structure was observed around q = 0.20 (long period 31.4 nm), and the intensity of scattering gradually increased.

This result shows that PMMA was not generated in all PPa layers between the crystal layers, but polymerization occurred mainly only in the PPa layer in which scCO ₂ was permeated and diffused, and as a result of the non-uniform formation of the PPa / PMMA layer, It shows that there are two types of amorphous regions, namely a layer and a PPa / PMMA layer.

However, when scCO ₂ Blend 100/109 is heated under the condition that the crystal melts (190 ° C., 1 min), the scattering peak is almost the same as that of Organic Solvent Blend, and the formed nanostructure is thermodynamically unstable and immediately collapses. Is shown.

Moreover, from the DMA curve, Tg of the PMMA chain of Organic Solvent Blend was the same as that of PMMA alone (around 130 ° C.), but the PMMA chain of scCO ₂ Blend decreased to around 100 ° C. This is considered to be because it was plasticized by entanglement with PP amorphous molecules. However, heating (190 ° C., 1 min) causes the nanostructure to collapse and rise again to around 130 ° C., the same as PMMA alone. This separation / disintegration of the nanostructure due to reheating can also be seen from the tensile test results.

Table 5 shows the weight gain (Weight gain) and PP content (Weight fraction of) of the polymer composite material (scCO ₂ Blend) prepared under various impregnation conditions (40 ° C., 5 min, 1 h and 6 h). The crystallinity calculated from the crystal melting enthalpy value (DSC) of the PP substrate in PP), Tm (° C.), and scCO ₂ Blend was shown.

It can be seen that the crystallinity of the PP substrate increases with scCO ₂ treatment (PP (scCO ₂ )) under impregnation and polymerization conditions. Moreover, although the crystallinity of scCO ₂ Blend varies with respect to the PMMA content, it suggests that the crystal region of PP is almost retained. As a result, it is considered that the impregnation and polymerization under the experimental conditions occur in the amorphous region.

FIG. 30 shows the SAXS profile of scCO ₂ Blend prepared under these impregnation conditions (40 ° C., 5 min and 1 h). In particular, at an impregnation time of 1 h, it is completely different from the SAXS curve (Fig. 1) of scCO ₂ Blend prepared by impregnation at 35 ° C. for 5 min, and corresponds to a PPc-PPa layer (near q = 0.5) observed with a PP substrate. The number of peaks was significantly reduced, a number of extremely small peaks were observed in a wide q-value range, and the scattering intensity increased rapidly on the small angle side. This is because scCO ₂ in which MMA is dissolved is impregnated and polymerized in almost all PPa layers while maintaining the PPc layer by increasing the impregnation temperature and time, and the PPc-PPa / PMMA repeating structure is formed by the generated PMMA. It strongly suggests that the long period increased.

Furthermore, when the scCO ₂ Blend impregnation time 1h 100/143 is heated (190 ° C., 1 min), the minute peak slightly increases, but no clear peak corresponding to the long period of the PP substrate PPc-PPa layer appears. It was.

From this result, it can be seen that scCO ₂ Blend prepared under the present impregnation condition retains the formed nanostructure almost as it is even when heated at a temperature at which the PP substrate crystals melt. That is, MMA is impregnated in almost all PPa layers in a PP substrate which is one continuous phase due to the characteristics of scCO ₂ , and PMMA produced by polymerization in situ is a new continuous phase in the PP substrate. Thus, it is suggested that IPN having a PP / PMMA co-continuous structure was formed, and separation and collapse of the nanostructure due to heating was alleviated.

  The novel polymer composite of the present invention exhibits thermal and mechanical properties that are completely different from those expected from conventional so-called polymer blends. In other words, the polymer composite of the present invention is a polymer material that is not usually thermodynamically dispersed in the order of molecular nanometers. Sexualization is possible.

FIG. 1 is a plot of LDPE / PMMAscCO ₂ blend, HDPE / PMMAscCO ₂ blend, LDPE / PMMA xylene blend, HDPE / PMMA xylene blend and calculated values against weight fraction.

FIG. 2 shows TG results of HDPE, HDPE / PMMA 8% hybrid, HDPE / PMMA 14% hybrid, HDPE / PMMA 20% hybrid, HDPE / PMMA 27% hybrid, HDPE / PMMA 54% hybrid, and HDPE / PMMA 102% hybrid.

FIG. 3 shows TG results of LDPE, LDPE / PMMA 0.7% hybrid, LDPE / PMMA 13% hybrid, LDPE / PMMA 33% hybrid, and LDPE / PMMA 136% hybrid.

FIG. 4 shows the impregnation of HDPE / PMMA, HDPE / PMMA 50% for 24 hours, HDPE / PMMA 95% for 24 hours, HDPE / PMMA 102% for 1 hour, HDPE / PMMA 95% annealing at 170 ° C. for 1 minute, HDPE / PMMA organic solvent blend The DMA curve (temperature rising rate 5 ° C./min, frequency 10 Hz) is shown.

FIG. 5 shows a DMA curve of LDPE, PMMA, LDPE / PMMA 99% impregnation for 24 hours, LDPE / PMMA 89% impregnation for 1 hour, LDPE / PMMA organic solvent blend, LDPE / PMMA 105% 24 hours impregnation annealing at 170 ° C. for 20 minutes. Temperature rate 5 ° C./min, frequency 10 Hz). The DMA curve is shown.

FIG. 6 shows HDPE, HDPE / PMMA organic solvent blend at 170 ° C. for 20 minutes, HDPE / PMMA 115.4% impregnation for 24 hours (AIBN 0.1 mol%), HDPE / PMMA 123.7% impregnation for 24 hours (AIBN 0.1 mol%), HDPE / PMMA 79.7% 24 hour impregnation (AIBN 0.1 mol%), HDPE / PMMA 50.3% 24 hour impregnation (AIBN 1 mol%), HDPE / PMMA 77.8% 24 hour impregnation (AIBN 1 mol%), HDPE / PMMA 109.5% 1 A plot of q of Lorentz-corrected Iq ² obtained by SAXS measurement of time impregnation (AIBN 1 mol%) is shown.

FIG. 7 shows HDPE / PMMA 50.3% impregnation for 24 hours (AIBN 1 mol%), HDPE / PMMA 50.3% impregnation for 24 hours (AIBN 1 mol%), an annealing 170 ° C. for 1 minute, HDPE / PMMA 77.8% for 24 hours impregnation (AIBN 1 mol) %), HDPE / PMMA 87.3% impregnation for 24 hours (AIBN 1 mol%) Annealing 170 ° C. for 1 minute, HDPE / PMMA 109.5% for 1 hour impregnation (AIBN 1 mol%), HDPE / PMMA 109.5% for 1 hour impregnation (AIBN 1 mol%) ) The plot of Lorentz corrected Iq ² obtained by SAXS measurement at 170 ° C. for 1 minute at annealing was plotted against q.

FIG. 8 shows HDPE / PMMA 115.4% 24 hour impregnation (AIBN 0.1 mol%), HDPE / PMMA 115.4% 24 hour impregnation (AIBN 0.1 mol%), annealing at 170 ° C. for 40 minutes, HDPE / PMMA 123.7% 24 Time impregnation (AIBN 0.1 mol%), HDPE / PMMA 123.7% 24 hour impregnation (AIBN 0.1 mol%) Annealing 170 ° C. 5 minutes, HDPE / PMMA 79.7% 24 hours impregnation (AIBN 0.1 mol%), HDPE / Obtained by SAXS measurement of PMMA 79.7% 24-hour impregnation (AIBN 0.1 mol%) annealing at 170 ° C for 5 minutes, HDPE / PMMA 79.7% 24-hour impregnation (AIBN 0.1 mol%) annealing at 170 ° C for 40 minutes. The plot of Lorentz correction Iq ² with respect to q is shown.

FIG. 9 shows SAXS measurement of LDPE, LDPE / PMMA organic solvent blend 170 ° C. for 20 minutes, LDPE / PMMA 82.2% 24 hours impregnation, LDPE / PMMA 84.4% 24 hours impregnation, LDPE / PMMA 106.7% 1 hour impregnation. The plot of Lorentz correction Iq ² obtained in step 1 against q is shown.

FIG. 10 shows LDPE / PMMA 82.2% 24 hour impregnation, LDPE / PMMA 104.7% 24 hour impregnation annealing 170 ° C. 20 minutes, LDPE / PMMA 84.4% 24 hour impregnation, LDPE / PMMA 84.4% 24 hour impregnation A plot of Lorentz-corrected Iq ² with respect to q obtained by SAXS measurement of annealing at 170 ° C. for 5 minutes and LDPE / PMMA 84.4% 24 hour impregnation annealing at 170 ° C. for 40 minutes is shown.

FIG. 11 is a TEM (magnification: 4,000 times) of HDPE / PMMA 100% organic solvent blend at 170 ° C. for 20 minutes.

FIG. 12 is a TEM of HDPE / PMMA 77.8% impregnation for 24 hours (magnification 4,000 times).

FIG. 13 is a TEM of HDPE / PMMA 87.3% 24-hour impregnation annealing at 170 ° C. for 1 minute (magnification 4,000 times).

FIG. 14 is a TEM of LDPE / PMMA 100% organic solvent blend 170 ° C. for 20 minutes (magnification 4,000 times).

FIG. 15 is a TEM of LDPE / PMMA 82.2% 24 hours impregnation (magnification 4,000 times).

FIG. 16 shows HDPE / PMMA 104.7% 24-hour impregnation annealing TEM at 170 ° C. for 20 minutes (magnification: 4,000 times).

FIG. 17 shows the TEM (magnification 7,000 times) of the sPS substrate itself.

FIG. 18 shows the TEM (magnification 7,000 times) result of the sPS / PMMA organic solvent blend.

FIG. 19 shows a TEM photograph (magnification: 7,000 times) of the sPS / PMMA supercritical blend.

FIG. 20 shows an enlarged TEM photograph (magnification 40,000 times) of the sPS / PMMA supercritical blend.

FIG. 21 shows a TEM of the result of annealing the sPS / PMMA supercritical blend at 300 ° C. for 1 minute. Here, (A) is a magnification of 7,000 times, and (B) is a magnification of 40,000 times.

FIG. 22 shows the results of TG analysis of sPS, PMMA, sPS / PMMA (scCO ₂ blend 1: 0.8), and sPS / PMMA (organic solvent blend 1: 1).

FIG. 23 shows the results of analysis of sPS, PMMA, sPS / PMMAscCO ₂ blend (85 wt%), and sPS / PMMAscCO ₂ blend (290 wt%) by DMA (heating rate 5 ° C./min, frequency 10 Hz).

FIG. 24 shows sPS, PMMA, sPS / PMMAscCO ₂ blend (85 wt%), sPS / PMMAscCO ₂ blend (95 wt%, annealing, 190 ° C., 1 min), sPS / PMMAscCO ₂ blend (79 wt%, annealing, 190 ° C., 10 min) ) Shows the analysis result by DMA (temperature increase rate 5 ° C./min, frequency 10 Hz).

FIG. 25 shows plots of Lorenz corrected Iq ² obtained by SAXS measurement with respect to q for sPS, sPS / PMMAscCO ₂ blend (65 wt%), sPS / PMMAscCO ₂ blend (330 wt%), and sPS / PMMA organic solvent blend. It was.

FIG. 26 shows sPS / PMMAscCO ₂ blend (65 wt%), sPS / PMMAscCO ₂ blend (65 wt%, annealing, 190 ° C., 1 min), sPS / PMMAscCO ₂ blend (96 wt%, annealing, 190 ° C., 5 min), sPS / A plot of Lorentz-corrected Iq ² obtained by SAXS measurement of PMMAscCO ₂ blend (79 wt%, annealing, 190 ° C., 10 min) against q is shown.

FIG. 27 shows a plot of Lorentz-corrected Iq ² against q obtained by SAXS measurement of sPS / PMMAscCO ₂ blend (330 wt%) and sPS / PMMAscCO ₂ blend (330 wt%, annealing, 190 ° C., 1 min).

FIG. 28 shows the results of a tensile test (stress / strain) for an sPS substrate, PMMA, sPS / PMMAscCO ₂ blend (86 wt%).

FIG. 29 shows a plot of Lorentz-corrected Iq ² against q obtained by SAXS measurement of PP / PMMA prepared under PP, organic solvent blending and impregnation conditions (35 ° C. for 5 minutes).

FIG. 30 shows a plot of Lorentz-corrected Iq ² versus q, obtained from PP / PMMA SAXS measurements, prepared with PP, an organic solvent blend, and various impregnation conditions (5 minutes at 40 ° C.).

Claims (4)

This is a polymer composite consisting of an amorphous polymer and a crystalline polymer that do not mix thermodynamically, and the non-crystalline PMMA polymer is a non-crystalline syndiotactic polystyrene that is a crystalline polymer. A polymer composite comprising a co-continuous interpenetrating network (IPN) dispersed in a nanometer order in crystal layers (all between spherulites, fibril microvoids, and lamella structures). This is a polymer composite consisting of an amorphous polymer and a crystalline polymer that do not mix thermodynamically, and the non-crystalline PMMA polymer is a non-crystalline syndiotactic polystyrene that is a crystalline polymer. A polymer composite characterized in that a co-continuous interpenetrating network (IPN) is formed by being dispersed in a nanometer order in crystal layers (all between spherulites, fibril microvoids, and lamellar structures). A manufacturing method in which a crystalline polymer substrate is impregnated with a monomer of an amorphous polymer that does not normally mix thermodynamically under a condition that the crystal structure of the crystalline polymer does not collapse, and the impregnated monomer is A production method comprising polymerizing in a substrate.   The production method according to claim 2, wherein the polymerization is performed by impregnating a monomer of an amorphous polymer in a supercritical fluid.   The production method according to claim 3, wherein the supercritical fluid is supercritical carbon dioxide.