TW201120105A - Foaming method for polycondensed polymer. - Google Patents

Abstract

A modification method for a polycondensed polymer is a method for extending the chain of the polymer that has been performed with polycondensation reaction and mainly comprises steps of impregnating the chain extender with a supercritical fluid and heating the mixture to perform the chain extending reaction, and demonstrating the modification performance through a foaming experiment. This invention can be applied to a polycondensed polymer virgin material and is suitable for modification of the recycled polycondensed polymer material to provide more applications for the recycled polycondensed polymer material, especially for the application of foaming process such that the life cycle of the polycondensed polymer material can be extended to provide more contribution to the sustainable environment.

Description

201120105 VI. Description of the Invention: [Technical Field of the Invention] The present invention is a method for modifying a hybrid polymer, and _ refers to a surface method of a polymer; this case is represented by PET, and the modification method is utilized. The method of dispersing the chain in the molecular structure of PET to increase the tension of the hearing and to overcome the phenomenon of molecular rotation makes the subsequent application more widely improved. [Prior Art] PET is a plastic knee product after condensation reaction. Therefore, after ρΕτ is recycled and processed, its molecular chain undergoes molecular degradation under the action of impurities. To overcome its problem, it is known to improve molecular degradation. The technology includes vacuum reinforcement, addition of stabilizers, solid state polymerization, addition of naphthalene storage, and addition of five types of chain extension. The former square wire can remove small molecules and radicals generated by processing, but can not increase the molecular weight of ρΕΤ; the third and fourth methods can increase the molecular weight of PET, but are limited by the slow reaction rate and material selection. Low-quality, high-cost and other conditions are not widely used; the last method is the most commonly used technology in industry and literature, although it can effectively increase the molecular weight of PET, but the product quality is not well-advanced. . In addition, the results of the foaming process test using conventional technology products on the market are not satisfactory. (Embodiment 1 of the prior art) A foam test was carried out in the same manner as in Specific Example 2 of the present application, without using a PET test piece containing a chain extender, directly using a test piece of a blow molding factory. The density of the foamed material after the foaming of the test piece without the chain extender was changed according to the second temperature, and the SEM photograph of the test piece in Table 1 was summarized in Table 2. Obviously, the density decreases with the rise of the second temperature, and its minimum density is also about 25 (rc). The trend of the second temperature and density change is similar to that observed in Table 1, but the chain extender is not added. The density is significantly larger than that of the PET added with the keying agent. It shows that the chain extender has a significant effect on the manufacture of the foamed material. If the cell structure is carefully observed, the phenomenon of cell collapse and collapse at high temperature can be observed. Obviously, The flight does not have enough _ melt tension reading cell structure to transfer the lower density ship structure. Therefore, PET without adding chain extender is not easy to foam. Table 1

4 201120105

The test piece of the blow molding factory and the 4.0 wt% of the PMDA chain extender were directly used in the kneading machine, and kneaded, and then a test piece was prepared by a molding machine. 1. Use Brabender mixer: temperature 255 C; speed 35 rpm; Tanfeng: Add PMMA of Φ\νΐ5 in reverse step, and continue mixing for 1 〇 minutes. 2. Remove the compound and make a 1 mm thick test piece using a hot press. The test piece exhibited a yellow-white unevenness phenomenon, and the white portion and the yellow portion were separately cut into a single portion and foamed in the manner described in the second embodiment of the present application. The yellow part of the foaming 皙 is only poorly d, and has almost no foaming ability. The density of the white partially foamed material changes with the second temperature, and the effect is shown in Table 3, and its SEM photograph is summarized in Table 4. The phenomenon of unevenness is caused by the fact that in the molten state, the mixture is immediately reacted to the gradual addition of the chain, and the distraction agent can not effectively disperse the chain extender in the entire _gel#, resulting in uneven mixing. The white portion of the knife was subjected to a foaming test. It was found that the density decreased as the second temperature rose, and then slightly increased after the minimum density, and the minimum density was about 骂. C or so. The second 201120105 trend of temperature and temperature changes is similar to that of most foamed plastics. However, because the mixing condition is not good, and the minimum density of the white preferred block is only about the same as that of the embodiment 2, the foaming of the yellow-white integral block is not good. If the cell structure of the white portion was observed, it was found that the cell structure was intact, and it was shown to be equivalent to that of Example 2. Therefore, it is presumed that the chain extension of the white portion should be equivalent to that of Example 2. When the chain extender is used in a considerable amount, the keying agent is not well mixed, so only part of the effect is revealed. Therefore, the efficiency is not good. Therefore, the use of a kneader directly to knead PET and a compounding agent will cause a problem of uneven mixing and a high amount of a keying agent. Table 3 First temperature (°c) Second temperature (°C) —-----—— Impregnation pressure (bar) Density (g/cm3> 270 230 120 0.2082 270 "240 120 ___________-_ 270 250 120 0.1572 270 260 120 ^^ ---------------~~'~~ 0.1980 Table 4

201120105 260〇C η. —_ ' ~ _ , . ,· CV ' ...Ύ Nitrogen ' 1 ν V-·* J :,,厂 '.二'.—Factory - 1 T , r- \f ^ 〜〉 s>r ;,,-, two one...-V production..two' less %ί rC- 乂'reduction one· • ,:r_ ............. The above-mentioned method of the inventor's cake can not effectively ensure the technology of the product, but it is considered and improved, and successfully developed the PET modification method and device thereof. 【Contents】 PETCpolyethyleneTerephthalate) ‘The annual use of 17〇(四)〇〇 嘲 全球 , , , , , , , , , , , 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 每年 在Therefore, PET recycling still has considerable room for growth. Because PET's county tension is insufficient, PET is fine (four), its molecular bond is under the action of impurities, causing its quantity to drop rapidly. If the ρΕτ at this time is foamed, the finished product will have no support due to the lack of sufficient tension. The structure, which switches to a lower density cell structure, causes the cell to collapse and collapse. At present, the shaft has a chain extension developed to solve this problem, but sister Lin. This is a _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Bubble structure. - The bribes that are generally suitable for the transfer of the ship's secrets will be effective in obtaining the foamed structure. Since the crystal is a crystalline polymer, the surface tension is insufficient. The PET fiber used in the market is 4, the iV (intrinsievi_ity) value is about ^~ heart; the PET used for blowing the bottle 201120105 is about (4).9. IV is higher than pET of 〇.9 or higher, and it is generally necessary to use a special synthesis technique. The solid phase polymerization technique must be produced under a high vacuum for a long period of time, so that the price is high. However, only the higher IV^ has sufficient body tension to form a stable bubble structure. Figure 1 is a schematic illustration of the applicability of low molecular weight PET and long chain linked PET for foaming applications. PET is a crystalline plastic, so it hardly flows before it reaches the melting point. Once the temperature is higher than the melting temperature, the viscosity drops sharply. Therefore, the low melt strength will not easily support the bubble structure and will not easily retain the gas in the solution. In the body. Therefore, it is necessary to change the intensity of blending through blending, grafting, and parenting. After the chain extension and the grafting treatment, the viscosity of the solution also increases because the molecular weight increases. Therefore, the temperature range suitable for operation becomes large, so that foaming is easy, and the crystallization speed of PET is slow, so that the cells have sufficient time to grow and shape. The present invention is to disclose a technique for performing uniform chain extension at a low temperature. Xllspo·2^

Upper limit for extrusion 77X77/7^: repon jgwa~ limit for bubbliDj ;window [ -U-i_J__

Temperature Figure i Suitable for the operating range of plastic foaming The extension of PET mainly utilizes the reaction of carbonic acid and hydroxyl groups at the end of the PET molecular chain to effectively extend the molecular chain. The added chain extender generally has to have two or more functional groups which can react with carbonic acid or hydroxyl groups, such as oxazoline, 201120105 or dihydrogen oxime, epoxy (epoxide) ), anhydride. Common chain extenders such as pyromellitic dianhydride (PMDA) 'tetraglycidyl diamino diphenyl methane (TGDDM), trimethylolpropane trigltcidyl ether (TMPTGE), 2, 2,, 2, '-(l,3, 5-phenylene)-tris-2- Oxazoline ' 2, 2' , 2,5-(1, 2, 4-phenylene)-tris-4, 4-dimethyl-2-oxazoline , 2, 2' , 2"-(l, 3, 5-phenylene) -tris-4, 4-dimethyl-2-oxazoline, 2, T, 2"-(l, 2,4-phenylene)-tris-5-methyl-2-oxazoline, 2, 2, ,2,,-( l, 3,

5-phenylene)-tris-5 -methy 1-2-oxazoline. To further demonstrate that the present invention achieves the foregoing objectives, the present invention simultaneously employs a pressure-inducing method for foaming' testing to improve its effectiveness. The foaming method is to contact the high-pressure gas at a temperature of the softening point of the plastic. After the gas dissolved in the polymer reaches equilibrium, the pressure is released, and the foamed plastic can be effectively obtained. For the purposes of the foregoing invention, the present invention upgrades PET, especially recycled PET, according to the following steps: (a) loading the chain extender and the PET material into the autoclave; (b) below the chain extension At the reaction temperature, the high-pressure gas is pumped to uniformly diffuse the chain extender in the pET structure; (c) The pet implanted with the chain extender is heated to a temperature above the chain extension reaction temperature to form an extended chain pET. The high pressure gas referred to in the step (b) generally refers to a gas which is easily dissolved in pET, such as carbon dioxide gas, or various compounds having high affinity with plastic, and mainly has the following four categories: 201120105 1. CFC (Chlorofluorocarbon) R11 (CC13F), R12 (CC12F2), R114 (CC1F2CIF2), Methyl Chloride (CH3C1), Methylene Chloride (CH2CI2), 2. HCFC (Hydrochloroflurocarbon): R141a(CH3CCl2F) 'R22(CHC1F2) > R142b(CH3CClF2) ' R124(CHFC1CF3); 3. HFC(hydrofluorocarbon): R134a(CH2FCH3), R235fa(CF3CH2CHF2), R365mfc(CF3CH2CF2CH3), R152a(CHF2CH3); 4. HC(hydrocarbon): cyclopentane, n-pentane, iso-pentane, n -butane, iso-butane, propane 〇In addition, the steps disclosed in the present invention refer to heating above the temperature of the chain extension reaction, and the means employed generally refer to heating by an oven, or by single-screw or twin-screw extrusion. The machine carries it out. Only the present invention has uniformly dispersed the chain extender in the polymer structure, so that the single-screw extruder can effectively carry out the chain extension reaction. Since the present invention can carry out the chain extension reaction using only a single screw extruder, and the single screw squeezing machine is inexpensive and has low lining consumption, the present invention can reduce the investment cost and the operation cost. The expanded PET ’ can be further tested by foaming to test its chain extension. The foaming method is as follows: (8) The PET is brought into contact with the high-pressure gas at a temperature above the softening point; (b) After the gas and the PET are saturated, the foaming pET can be obtained by releasing the pressure. If the inappropriate PET material is used, the density of the foam is high, and the cell structure is incomplete; 201120105 If the appropriate PET material is used, the foam density is low and the cell structure is honeycomb-like. By the above method, the polycondensation polymer modification method of the present invention which forms the present invention, the advantages and the advantages obtained by the present invention are improved as follows: • The high pressure gas used in the present invention is a critical pressure, The fluid state above the temperature, the chain extender brought by the supercritical fluid, which can effectively disperse the chain extender uniformly in the ρΕΤ structure molecule, and can improve the previous mixing of the chain extender by the mixer. The problem of uneven mixing and high requirements for chain extenders, as well as avoiding the energy consumption of operating the vacuum under vacuum and the high investment in equipment. 1. Since the supercritical fluid is used for the implantation of the chain extender, the material after the ink bleed will be directly dried, and only the static dissipating is required, and the process is simple. 3. The present invention can effectively increase the IV value of bismuth so that it has sufficient glare tension to form a stable structure, which makes the plastic easy to foam, and provides another new application material for the recovered pET. Lu Si. The supercritical fluid used in the present invention is easy to recycle, can reduce the impact on the environment, and simplifies the complicated work of the previous linings, and has the cost of manufacturing less. [Embodiment] As shown in the figure - the present invention is a method for polymerizing a polycondensation polymer (IV), and the modification is characterized in that a jujube agent is carried into a polymer structure by a supercritical fluid, and then a chain extension reaction is carried out by heating. To increase its melt tension and overcome molecular degradation. The main private technical steps of the present invention are as follows, and the hybrid polymer of the towel is implemented by PM, as shown in Fig. 2: !. The chain extender and the recovered cockroach are simultaneously loaded with high secrets, and if necessary, will be assisted The solvent is simultaneously loaded in 201120105; 2. The carbon dioxide from the gas cylinder 15 (the carbon dioxide as the implementation of the present invention) is precooled by the cold header 141, pressurized by the liquid high pressure system 14, and temporarily stored in the buffer tank η, and The pressure is adjusted by the back pressure valve 151; 3. After the entanglement force is required by using the damper 12, the needle 121 between the high pressure switch 11 and the buffer tank 13 is opened, so that the high resident U is filled with high pressure carbon dioxide; Start the heating and temperature control device lu of the high-pressure dad U. After the temperature and pressure reach the set bar, hold the temperature for a period of time, let the chain extender diffuse into the PET structure; 5. The bubble pressure is taken out and expanded. The pet test piece of the chain agent is selectively allowed to stand for the carbon dioxide wire dissolved in ρΕτ, and the impurity contains more than the temperature of the PET plus red (without stirring or kneading), so that the PET completes the chain extension reaction. (Example 1) The chain extender is dispersed in the molecular structure of the PET. • The PET recovered by the bottle blowing is used to dry the thief PET in an oven. After the drying is completed, the recycled PET is placed in the mixer. The mixture was heated and kneaded, and then formed into a ρΕτ test piece by compression molding in a press molding machine. Impregnation of the Expanding Agent In addition to the use of carbon dioxide as a carrier to carry the chain extender into the pET molecular structure alone, attempts have been made to increase the amount of chain extender adsorbed by the use of a co-solvent. It is divided into two parts: supercritical carbon dioxide alone and auxiliary solvent in supercritical carbon dioxide. (1) Supercritical carbon dioxide alone 12 201120105 1. PET test piece weighs. 2. The chain extender weighs (about 5%, or 10% of the weight of the PET sheet). 3. Place steps 1 and 2 simultaneously into the autoclave. 4. Inject high-pressure dioxide discs and use carbon dioxide to carry the chain extender evenly into the PET molecular structure. 5. Remove the PET test piece, weigh it after overnight carbon dioxide escape, and calculate the amount of chain extender implant. 6. After the PET test piece implanted with the chain extender, the foam test can be prepared. The results are as follows

(A) Chain Extender: PMDA (5%) Table 5 No. Time (hr) Temperature (°C) Pressure (psi) Wo(g) Wf(g) △W= ^ (W〇- Wf)/W〇Α1 2 80 3000 1.2784 1.2984 0.0156 ' Α 2 2 50 6000 1.1136 1.1220 0.0075 , A3 2 80 6000 1.2529 1.2777 0.0198 , Α 4 4 80 6000 1.2819 1.3167 0.0271 , Α 5 6 80 6000 1.3048 1.3517 0.0359 , Α 6 6 100 6000 1.1950 1.2448 0.0417 Α 7 8 100 6000 1.2096 1.2477 0.0315 , Α 8 2 120 6000 1.2774 1.3233 0.0359 , Α 9 4 120 6000 1.2723 1.3185 0.0363 Α 10 1 100 7000 1.2496 1.2773 0.0222 ^ All 2 100 7000 1.2306 1.2738 0.0351 , A12 6 100 7000 1.2172 1.2557 0.0316 ^ A13 10 100 7000 1.2298 1.2783 0.0394 ~ ----- --

W. : Loaded PET weight

Wf=weight after implanting the chain extender Δ\ν=the added weight fraction of the implant chain extender is shown in Table 5, the number Α2 and A3 are compared, the temperature rises, and the amount of chain extender implant is obviously 13 201120105. Since the Tg point (glass transfer temperature) of PET is about 90 degrees, it is necessary to turn it into a molten state. The temperature condition is close to the Tg point of ρΕτ, so the amount of chain extender implanted. It is obviously twice as much as μ; the temperature of Α8 is higher than the Tg point of ρΕτ, which is almost twice as much as that of A3. It can be seen that the higher the temperature, the higher the chain extender content than Wei. When this is changed to 彳·Tg, the rate of yuppie is slow, so the amount of 2 hours of impregnation can be implanted. If it is the same as Tg, the amount that can be implanted in 2 hours is already close to saturation, and the increase in the amount of implantation that can be caused by the continued increase in time is also limited. The comparison of time can be seen from A1〇~A13, and the time of impregnation will increase, but after 2 trees, the degree of increase is limited. If the pressure is changed, it can be seen from the comparison of A1 and A3 that the pressure increases and the specific gravity of the chain extender increases. Therefore, the preferred chain extender implantation temperature of the present invention is at a temperature above the Tg of the plastic, and in order to complete the diffusion of the chain extender, the time required for implantation is about 2 hours. (B) Chain extender: DGA Table 6

The comparison of B2 and B3 in the table can be found that the higher the temperature, the more the chain extender is implanted. As the pressure increases, the specific gravity of the chain extender increases slightly, and B1 & B3 can be compared. For higher than Tg to 14 201120105

The conditions of the upper temperature, 6 hours and 8 hours have little effect on the amount of chain extender implanted. (C) Chain Extender: TMPTGE Table 7 No. TMPTGE Time (hr) Temperature CC) Pressure (psi) Wo(g) Wf(g) △W (W〇- Wf)/W„ C1 5% 2 80 3000 1.4632 1.4877 0.0167 C2 5% 2 50 6000 1.2631 1.2728 0.0077 C3 5% 2 80 6000 1.2653 1.2913 0.0205 C4 10% 6 100 6000 1.1565 1.1840 0.0238 C5 10% 8 100 6000 1.2036 1.2331 0.0245 From the above results, we can see the results of the sample C5. In other samples, C2 and C3 in the table show that the higher the temperature, the more the chain extender is implanted. C1 and C3 can increase the pressure and increase the chain extender content. For conditions above Tg, 6 Hours and 8 hours have little effect on the amount of chain extender implanted. (2) Adding auxiliary solvent to supercritical carbon dioxide 1·PET test piece weighing 2. Chain extender and auxiliary solvent weighing (each about pET piece weight 5%) 3. Put both steps 1 and 2 into Gory Dad. 4. > Inject high-pressure carbon dioxide and use carbon dioxide to carry the chain extender evenly into the molecular structure of ρΕτ. 5. Take out the PET test piece 'wait overnight After the carbon dioxide is dispersed, weigh it and calculate the amount of chain extension. 6. After passing through the pET test piece, the standard can be obtained. The foaming test was carried out. The results are shown in the following table 2011 15 201120105

P-xylene and the test to add a co-solvent to increase the number of people in the chain extension ^ two auxiliary solvents,

Octane, in which the effect of P-Xylene is better than the temperature above ^, the ai4 to ΑΠ can be found to increase the time, and the increase of the implantation amount is limited after 2 hours. (Example 2) Foaming experiment 1_Open the carbon dioxide cylinder 'starting liquid pump, cooler, and establish the pressure of the buffer tank; 2. Place the PET test piece containing the chain extender into the impregnation tank; 3. Start the impregnation tank heating , until the temperature reaches the first heating temperature above the chain reaction temperature; 4! Open the needle valve between the impregnation tank and the buffer tank, and adjust the pressure of the impregnation tank with the pressure regulating valve, and continue the pressure with the first temperature for half an hour. 5. Adjust the temperature of the impregnation bath to a temperature slightly higher than the second heating temperature above the softening point temperature, and hold the temperature for more than half an hour; 6. Open the ball valve at the bottom of the impregnation tank to release the pressure, and foam the PET test piece; The foamed test piece was subjected to density measurement and microstructure observation of a scanning electron microscope (SEM, sunning Eleet K) n Microscopy; the results are shown in the following table: The density of the foamed material after the foaming of the test piece No. A15 varies with the second temperature. The situation is summarized in Table 9, and the SEM photographs thereof are organized in Table 1〇. Obviously, the density decreases with the second temperature on 201120105, and its minimum density is about 250 °C. If the cell structure is carefully observed, it can be found that the cell is still intact at a relatively high temperature of 260 °C, and the percentage of cell wall rupture is not too high. Table 9 First temperature (°c) Second temperature (°C) Impregnation pressure (bar) Density (g/cm3) 270 230 120 0.3110 270 240 120 0.1883 270 250 120 0.1104 270 260 120 0.1710 Table 10 Partial area

230〇C

240〇C

250〇C

17 201120105

(Example 3) Foaming test in which various chain extenders were added Other test pieces of No. A1, A19, B5, and C5 were foamed, and the density of the foamed materials was as shown in Table 11. First temperature (°c) Second temperature ΓΟ Impregnation pressure (bar) Density (g/cm3;) A19 270 250 120 0.2157 All 270 250 120 0.2729 ^ B5 270 250 120 oSTo One L7c5 270 250 120 • '— 0.2544 -- The foamed PET foam can also be obtained for the B5 and C5 samples of the chain extender different from PMDA, or the test 'A19 and All' with different implantable mineralizer methods. It is shown that the use of a chain extender in the super-swanning carbon dioxide to implant a chain extender can indeed effectively produce a network structure of a polymer chain. As compared with the prior art embodiments, according to the present invention, a modification method of the polyester material can be provided, which can recover and reuse the recycled raw material, and can have a better melt tension and an increased molecular weight. Large PET, compared with the conventional technical method, has the following advantages: 1. After the chain extension and graft modification of the PET of the present invention, the molecular weight and the melt tension are increased, so that the operating temperature range becomes larger. It is easy to foam; 2. The invention is also environmentally friendly, and the supercritical fluid used is easy to recycle, which can reduce the pollution of the environment of 18 201120105. 3. The invention can simplify the lion-making process of the conventional technology, and the production silk is relatively smooth. It is easy to control and can effectively reduce the formation of fish eyes and opaque defects. 4. The invention can improve the production of the prior art, make it a waste material, and can be widely used in industry. The above-mentioned Embodiments 1 to 3 are intended to be in the form of a preferred embodiment of the present invention, and are not intended to limit the scope of the present invention. . Embodiments 1 and 2 of the prior art are for comparison purposes only and are not core technologies of the present invention. In summary, the case is truly innovative in terms of technical thinking, and should fully comply with the patent cases of novelty and applicability. You are requested to approve the patent application of this invention. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a flow chart showing the steps of a polycondensation polymer upgrading method of the present invention. Figure 2 is a process diagram of a polycondensation molecular modification method of the present invention. [Main component symbol description] 101 Step 1 102 Step 2 103 Step 3 11 Business pressure dad 111 Temperature control device 112 High pressure dad pressure indicator 201120105 12 Pressure regulating valve 121 Needle valve Π Buffer tank 131 Buffer tank indicator 14 Pump 141 Cooler 15 gas cylinder 151 back pressure valve

Claims (1)

201120105 VII. Scope of application for patents·· 1. A method for upgrading polycondensation polymer, which comprises (a) loading a chain extender and a polycondensation polymer into a high pressure dad; (b) at a temperature lower than the chain extension reaction temperature Pumping high-pressure gas to evenly diffuse the chain extender into the polycondensation polymer structure; (c) Heating the implanted ship __ polymer to a temperature above the reaction temperature to form an extended chain polycondensation polymer . 2. For the application of the patent item i, the polycondensation polymer refers to a polymer obtained by a condensation reaction, such as PET, PEN, PC, Nylon, and the like. 3. As requested in item i of the patent application scope, the high pressure gas must be in a fluid state at a critical pressure and a critical temperature, and may be a gas such as carbon dioxide or soluble in a polycondensation polymer material. 4. For example, the scope of patent application! Optionally, the keying agent may be a molecule of ρΜ〇Α, GDDM TMPTGE or a functional group having a graft or a hydroxyl group reactive with or with two gamma. 5. If required by item 1 of the patent application, an auxiliary solvent may be added to the high pressure gas to increase the content of the chain extender. 6. If you want to request the fine item 5, the cap helps to dissolve the compound as 0_e, P-Xylene or other compounds that can increase the amount of chain extender implanted. 7. For the scope of the patent towel, item 1 is requested, and the towel heating method is carried out in a single-turning machine, a twin-screw extruder, an oven or a device with a heating effect. [S ] 21 201120105 8. If you apply for a patent, please request the first item, and heat the chain-extended polycondensation polymer to a temperature above the softening point, and simultaneously dissolve the foaming gas into the chain-extended polycondensation polymer. The pressure-reducing polycondensation polymer can be obtained by pressure relief. twenty two