KR101001524B1 - High viscosity modified biobased and biodegradable polymer for the application of low density extrusion foaming - Google Patents

Abstract

The present invention relates to a modified plant-derived biodegradable resin composition having a high melt viscosity suitable for high magnification foaming. The present invention relates to a resin of commercialized polylactic acid, which is a plant-derived biodegradable resin, based on the weight of the polylactic acid and the double bond and epoxy. 0.01-10% by weight of a monomer having a functional group and 0.01-0.4% by weight of an initiator were added to provide a resin having a high melt viscosity having a gelation degree of less than 5%. It provides not only biodegradable but also highly productive resins, which are completely decomposed into water and carbon dioxide by microorganisms after disposal, and the produced carbon dioxide is a carbon dioxide cycle without accumulation of carbon dioxide that is produced as a reusable raw material by plant photosynthesis. It provides a high viscosity modified plant-derived biodegradable resin for foaming high magnification.

PLA, GMA, initiators, biodegradation, carbon dioxide

Description

High viscosity modified biobased and biodegradable polymer for the application of low density extrusion foaming with the addition of monomers having two reactors capable of condensation polymerization and one reactor capable of radical reaction

The present invention relates to a modified plant-derived biodegradable resin composition having a high melt viscosity suitable for high magnification foaming, and more specifically, it is biodegradable and does not emit carbon dioxide, thereby reducing global environmental loads and various magnifications including high foaming. It relates to a high viscosity modified plant-derived biodegradable resin composition capable of producing a foam of high magnification foam.

Conventionally, non-degradable polyolefin resin foams and polyurethane resin foams, which have been used as raw materials for blow molding and foams, have been widely used industrially because they have excellent moldability, are easy to manufacture, lightweight, and have excellent thermal insulation and buffering properties. .

However, such resin foams put a great burden on the global environment due to their non-degradation upon disposal. In addition, since these resins are produced as petrochemical raw materials, their use is limited by the CO2 reduction Tokyo Convention.

Thus, in recent years, research and development on foams corresponding to non-degradable and carbon dioxide emission regulations have been actively conducted.

For example, biodegradable resins decomposed by microorganisms in a natural environment such as aliphatic polyester homopolymers or crosslinked foams using peroxides or aliphatic polyester-aromatic polyester copolymers are researched and developed to form molded articles and films. And commercialized as fibers and developed for extruded foams of some biodegradable resins, but these biodegradable resins are subject to carbon dioxide emission restrictions because they produce their raw materials from petrochemical raw materials.

Therefore, it is necessary to develop a resin that is easy to obtain high magnification foam without being subject to biodegradability and carbon dioxide emission regulation. Recently, mass production of lactone resin polymerized with polymers by producing monomers from plants such as corn has been performed. The resin could not be molded into a blow molded article or foam due to the low melt viscosity of the polyester.

As a method of manufacturing a resin for foaming to compensate for these disadvantages, Japanese Patent Laid-Open No. 11-279311 proposes a foam using a lactone resin, but in a normal state, the degree of collapse during crosslinking is only achieved by radiation treatment. Since it progresses simultaneously, it is difficult to obtain the melt viscosity for fully maintaining a bubble at the time of foaming, and it is difficult to obtain foam with a favorable surface form. That is, irradiation in the vicinity of room temperature requires a large radiation dose of 200 kGy, and in order to solve this problem, it is described that it is preferable to melt the lactone resin above the melting point and then perform crystallization without reaching crystallization. Easily a foam having a high degree of crosslinking (gel fraction) could not be obtained. In addition, since the degree of gelation is high, it is difficult to apply modified resin to continuous foaming, and when the degree of crosslinking is high, stabilization of the foaming cell is extremely difficult.

In addition, Korean Patent Laid-Open Publication No. 10-2004-0066148 proposes a method of crosslinking a resin using an electron beam after producing a biodegradable resin containing a polyfunctional monomer having at least two unsaturated bonds in a molecule into a sheet. . However, this method is impossible to recycle after use with a sheet having a gelation degree of at least 5% that compares the crosslinking rate under the influence of multifunctional groups, and cannot use a conventional continuous foaming machine. In addition, if the thickness of the irradiated object exceeds 1mm, the radiation does not reach the inside, so that the bubbles inside are uneven at the time of foaming. It is difficult to produce a reliable uniform foam sheet because the viscosity is significantly reduced due to the decrease in molecular weight by the bubble becomes very unstable.

In another technique, a method of preparing a resin having high viscosity by cross-linking and reforming with a peroxide initiator has been proposed, but since the gelation degree is not easy to process after modification, it is actually foamed with a resin having a lower viscosity. In this case, the foaming temperature should be greatly lowered to obtain high viscosity, but at low processing temperature, continuous expansion of high magnification is almost impossible (D. Carlson, P. Dubois, and R. Narayan, Polym. Eng ., & Sci . , 38 (2), 311-321 (1998).)

In addition, the method of using a chain extender as a method of increasing the molecular weight while maintaining the linearity of the molecular chain was introduced, but the reaction time is long, or the toxicity of the chain extender is limited to the application as a final product. (SS Ray and M. Okamoto, Macromol. Rapid. Commun., 24, 815, (2003))

In addition, recently, a method of increasing the viscosity by preparing a nanocomposite has been announced, but in this case, a large amount of nano-inorganic material, which is a foreign material, is so destroyed that the foaming cell is destroyed early, which is not suitable for high foaming. (Y. Di, S. Iannace, ED Maio, and L. Nicolais, J. Polym Sci:.. Part B, 43, 689 (2005))

On the other hand, those that are known to be biodegradable and not subject to carbon dioxide emission control are those produced by ring-opening polymerization of glycolide or lactide.

Among these, polylactic acid (PLA), which can be mass-produced, has been widely applied to films, sheets, injection molded articles, fibers, and the like. As a study on modifying polylactic acid, a method of using a chain extender has been introduced. Long reaction times and the toxicity of chain extenders have severely limited their application to the final product (SS Ray and M. Okamoto, Macromol . Rapid . Commun ., 24 , 815, (2003)).

In order to solve the problems as described above, the present invention is to minimize crosslinking (less than 5% gelation, preferably less than 3%) and increase the molecular weight while maintaining branching or linearity of the polymer chain by adding functional monomers. Unlike the resin modified by the conventional crosslinking method, it is very easy to process into a continuous foam sheet, and provides a resin with excellent productivity as well as biodegradability derived from plants, and is completely decomposed into water and carbon dioxide by microorganisms after disposal. The purpose of the present invention is to provide a high-viscosity modified high viscosity modified plant-derived biodegradable resin composition suitable for a carbon dioxide circulation cycle without the accumulation of carbon dioxide, which is produced as a reusable raw material again by photosynthesis of plants.

A feature of the present invention for achieving the above object is a 0.01-10% by weight of a monomer having a double bond and a functional group of epoxy with respect to the weight of the polylactic acid in the resin of the commercialized polylactic acid which is a plant-derived biodegradable resin It is characterized by a high melt viscosity resin composition having a degree of gelation of less than 5% by adding 0.01-0.4% by weight of initiator.

The present invention provides a resin composition of high melt viscosity and storage modulus having a gelation degree of less than 5% by adding a monomer having a double bond and an epoxy functional group to a resin of a commercialized polylactic acid which is a plant-derived biodegradable resin. Since the chain is not crosslinked and is linear or branched, extrusion magnification of any magnification is possible. In other words, the resin according to the present invention has a gelation degree of less than 5%, maintaining the thermoplastic properties as it is, there is an effect to obtain a continuous foam sheet of various magnifications using an olefin resin extrusion foaming machine currently used.

Hereinafter, an embodiment of the present invention will be described.

The high-viscosity modified high viscosity modified plant-derived biodegradable resin composition according to the present invention is based on polylactic acid, and includes one epoxy group capable of rapid condensation polymerization with a double bond, which undergoes one radical reaction as luperox as a reaction initiator and one functional monomer. Or glycidyl methacrylate (GMA) having a maleic anhydride group or an isocyanate group at the same time. When the monomer has three or more functional groups in the above-described configuration, crosslinking proceeds and thus is performed as in the conventional method. Machining is difficult after modification.

Other examples of such monomers include 1,2-EPOXY-9-DECENE, 1,2-EPOXY-5-HEXENE, 4-VINYL-1-CYCLOHEXENE-1,2-EPOXIDE, LIMONENE-1,2-EPOXIDE, ALLYL There is GLYCIDYL ETHER.

As the initiator, dialkyl peroxide, which is an oxygen peroxide (peroxide) -based initiator, in addition to luperox, is used. Examples thereof include α, α'-di (t-butylperoxy) diisopropylbenzene; 2,5-dimethyl-2,5-di (t-butylperoxy) hexane; t-butylkermil peroxide; Di-t-butyl peroxide; Also 2,5-dimedyl-2,5-di (t-butylperoxy) hexyne-3; 2,5-dimethyl-2,5-di- (t-butylperoxy) hexane.

On the other hand, in the above configuration, the monomer is added in an amount of 0.01-10% by weight based on the weight of the polylactic acid, and the initiator is added in an amount of 0.01-0.4% by weight based on the weight of the polylactic acid.

1. Experiment

reagent

Polylactic Acid (Nature Work PLA Polymer 4032D) was purchased from Cargill Dow LLC and dried at 50 ° C. for 24 hours. Glycidylmethacrylate (GMA) as a functional monomer and 2,5-bis ((tert-butyl peroxy) -2 and 5-dimethyl hexane (Luperox) as reaction initiators were purchased from Aldrich and used without purification. .

Sample Preparation

The compositions of the samples prepared in this study are shown in Table 1.

The content of GMA and initiator was defined as the amount of the substance (g) per 100 g of PLA (pound per hundred; phr).

First, PLA and the reaction initiators, Luperox and GMA, were mixed in a plastic bag with the composition shown in Table 1 and premixed, followed by melt mixing using a twin screw extruder (SM PLATEK Co. Ltd., TEK 30, Korea). The twin screw extruder is a co-rotating type with a screw diameter of 30 mm and a length / diameter (L / D) ratio of 36. The screw rotation speed was 150 times per minute, the barrel temperature was maintained at 130-190 ° C, the die temperature at 185 ° C, and the extrusion speed was adjusted to 12 kg / hr. The prepared sample was cut into chips and dried at 50 ° C. for 24 hours.

analysis

The gel fraction, which is a qualitative measure of the degree of crosslinking and branching of molecules, was measured as follows. First, the gel is separated from the modified polycaprolactone by operating in a chloroform solvent for 24 hours using a soxhlet apparatus. The separated gel was dried and weighed. Gelation refers to the weight percentage of gel relative to the initial sample.

The thermal properties were measured by glass differential temperature (T _g ) and melting temperature (T _m ) using differential calorimetry (DSC; Perkin-Elmer Pyris 6). In order to make the thermal history the same, the sample was first heated to 200 ° C at a heating rate of 20 ° C / min, stopped for 5 minutes, and then quenched to 0 ° C. Thereafter, the temperature was raised to 200 ° C. at a temperature increase rate of 10 ° C./min, and thermal properties were examined.

The crystallization temperature was the peak value of the exothermic curve that appears when the second temperature is cooled again to 10 ℃ / min.

The change in composite viscosity, storage modulus (G ') and loss modulus (G ") of samples with frequency was measured using Advanced rheometric expansion system (ARES; Rheometric Scientific Co. Ltd.). A disc with a diameter of 25 mm and a thickness of 2 mm was prepared by compression molding, and the melting point elasticity was investigated while the measurement temperature was fixed at 190 ° C. at 5% and the frequency was changed from 0.1 to 100 rad / s.

Biodegradability was measured under aerobic composting conditions by the ISO 14855 method. Cellulose was used as a standard sample and the chamber was kept at 58 ± 2 ° C. Carbon, hydrogen, and oxygen component analyzes were analyzed with an elemental analyzer equipped with a TCD detector (EA 1108 CHNSO, Fisons, Italy).

3. Results

end. Free of functional monomers PLA Chemical modification results

In Table 1, the gelation and thermal properties of the modified PLAs containing no functional monomers (ID # 8,15,22) are recorded according to the content of the initiator, and their rheological properties with frequency are shown in FIGS. Shown in

In view of the degree of gelation, the gelation degree is 0.9% when the content of the initiator is 0.1 and 0.3 phr, and increases to 3.1% when 0.5 phr. This means that when the content of the initiator is low, the reaction by the initiator is superior to the crosslinking reaction, and when the amount of the initiator is large, the crosslinking reaction also proceeds a lot. Such a chain structure is known to have a great influence on the rheological properties of the polymer.

1 and 2, when the content of the initiator is 0.1 and 0.3 phr, the compound viscosity and storage modulus are 2.5 times and 1.8 times higher than those of the unmodified pure PLA, respectively, but when 0.5 phr of the initiator is added, the composite viscosity is rather high. Slightly decreased and the storage modulus is inverted to the value of pure PLA near the frequency of 10 rad / s. These composite viscosities and storage modulus are directly related to the melt strength, which shows melt processability, so that the PLA melt strength can be improved by simple chemical modification, but it is insufficient for low density foaming or application to blow molding products.

Compound viscosity and storage modulus show a decrease in the content of the initiator increases. This is because branching and crosslinking of the chain also occur due to the addition of the initiator, but at the same time, a chain cleavage reaction occurs. The flow curve shows that the modified PLA is more shear dependent than the unmodified PLA, resulting in branched or crosslinked chains.

logG 'vs. logG "plot (also called modified Cole-Cole plot) is shown in FIG. 3.

Log G 'vs. The log G "plot will be on the same line regardless of molecular weight and measurement temperature in monocomponent polymers, but as the branching and crosslinking of the molecular chains change, the curves will be on different lines. "The plots are all straight, but the slope of the modified PLA is less than that of pure PLA. It can be seen that the modified PLA has a high elasticity (elasticity) of pure PLA beam and this property is based on the molecular weight distribution having a large crosslinking and branching.

The similar curves of PLA modified with 0.1 and 0.3 phr of initiator are considered to be due to the similar chain structure of the molecule.However, as a result of the composite viscosity, the molecular weight of PLA modified with 0.3phr of initiator was changed to 0.1phr of initiator. You can guess less. This is thought to be the result of molecular weight reduction by cleavage of the molecular chain.

The heat of fusion of crystals (ΔH _f ) is a comparative data for the degree of crystallinity. The heat of fusion of PLA increased significantly regardless of the addition of initiator.

In general, the degree of crystallinity is affected by the molecular weight change, the formation of crystals by branching and crosslinking, the rate of growth, and the completeness of the crystals. The degree of crystallinity is determined by the rate of nucleation of crystals and the rate of growth of crystals, which depend on the rate of diffusion of molecules around the nucleus at the same thermal history. It is also known that the presence of branch or crosslinking points in the molecule reduces crystal perfection and crystallization rate. That is, low molecular weight molecules generated by chain breakage of molecules contribute to an increase in crystallinity, but branched crosslinking acts vice versa.

The crystallinity of the modified polylactic acid of the present invention showed the opposite tendency to increase greatly in spite of the factor of decreasing the crystallinity of branching and crosslinking. This may be explained by the fact that the crystallization degree does not increase without the aid of the nucleating agent because of the very slow crystallization rate of the polylactic acid, and the initiator used in the present invention binds to the PLA molecule and serves as an organic nucleating agent.

I. With functional monomers PLA Chemical modification results

Prior to chemical modification, the effect of functional monomers on the physical properties of pure PLA is examined first (ID # 2-7).

GMA is a multifunctional monomer having one double bond and an epoxy group. First, as shown in Table 1, the change in T _m did not change depending on the monomer content, but the T _g of 3,5 phr PLA to which a relatively high amount of monomer was added decreased. This change in T _g shows that GMA is a good plasticizer for PLA.

In addition, in the present invention, it can be seen that the increase of heat of fusion (ΔH _f ) is increased even when a small amount of GMA is added, which means that GMA plays a role of organic nucleating agent by reaction in addition to plasticizer, and this epoxy group of GMA is melted. When mixing, the hydroxyl group and etherification of the PLA terminal and the esterification of the carboxyl terminal and the esterification (estrification) cause the GMA present at the terminal to act as an organic nucleating agent.

Referring to FIG. 4, the composite viscosity of a case in which the tendency of the complex viscosity change following the GMA amount less the amount of monomers similar to the variation tendency of the T _g is the viscosity, the smaller the one similar to the value of pure PLA, the content is more than 1phr. This is because the monomer serves as a plasticizer of PLA.

In the modified Cole-Cole curve of FIG. 5, the curves of all the samples are almost exactly coincident except for some sections of low elastic modulus. This result is considered to be because there is no branching or crosslinking reaction of PLA by the addition of GMA which is a monomer alone. The degree of gelation was all 0%, indicating that no crosslinking reaction occurred.

The results of modified PLA (ID # 8-14) with the initiator content fixed at 0.1 phr and the composition of GMA changed to 0.1-5 phr are shown in Table 1 and FIGS. 6-8, respectively.

The change in thermal properties does not show a significant difference from the values of PLA added only with GMA even when chemically modified with addition of GMA. However, the degree of gelation is insignificant between 0.1 and 1.2% but slightly increased, indicating the possibility of branching or crosslinking reaction. However, the rheological properties, unlike the thermal properties, showed much improved properties than the rheological properties of PLA containing only GMA.

As shown in FIGS. 6 and 7, except for the sample containing the most GMA (ID # 14), all of the remaining modified PLA shows a higher composite viscosity and storage modulus than the pure PLA, and does not include monomers, but only as an initiator. Compared to the modified PLA (ID # 8), all of the samples containing GMA 3 and 5 phr (ID # 13,14) showed higher composite viscosity and storage modulus.

In particular, the composite viscosity of PLA (ID # 10) modified PLA containing 0.3 phr of GMA was the highest in the low frequency range, GMA 0,1. It can be seen that the values of modified PLA containing 0.5 and 1.0 phr have almost similar values.

This peak is 3.7 and 1.5 times higher than the composite viscosity of pure PLA and initiator modified PLA, respectively, indicating that GMA participated in PLA branching, chain extension or crosslinking.

Therefore, it can be judged that addition of GMA contributes to branching of PLA chain or formation of high molecular weight linear chain.

The composite viscosity of the sample added with 5 phr of GMA was less than that of pure PLA. This is because GMA, which failed to participate in the reaction, acted as a plasticizer.

The storage modulus is higher than the pure PLA value in the low frequency range, but lower than the PLA value in the high frequency.

And, as shown in the general formula (1), it can be seen that in the reaction extrusion step, reactions such as radicalization reaction, etherification reaction esterification, chain cutting, branching, crosslinking, and the like proceed considerably. That is, the pure PLA initiated by the initiator radical removes the hydrogen of the quaternary carbon to produce a polymer radical, and the reaction such as esterification or etherification of the terminal of the PLA and GMA, and radicalization of the GMA itself proceeds. It is estimated that the chain cutting, branching, and crosslinking reactions proceed afterwards.

In the present invention, after the radical radicalization of GMA by the homopolymer of GMA and the initiator, PLA molecules and ester or etherification reactions are also possible.

Looking at the modified Cole-Cole plot of FIG. 8, the curves of all modified PLAs deviate from the pure PLA curve. This means that the branching and crosslinking reaction of the PLA chain proceeded by the addition of the initiator, but the crosslinking reaction appears to be very weak as a result of the degree of gelation.

Changes in physical properties of the samples (ID # 15-21) when the content of the initiator is included in 0.3 phr are shown in Table 1 and FIGS. 9 to 11.

The thermal properties of T _g , T _m , T _c , ΔH _f, etc. do not show a significant difference even when the initiator content is increased from 0.1 to 0.3 phr. This is thought to be because both chemical changes are similar.

However, in the degree of gelation, the degree of gelation of the modified PLA (ID # 16) containing 0.1 phr of GMA was 2.5%, indicating that the crosslinking reaction was more advanced than other samples.

As shown in FIGS. 9 and 10, the composite viscosity and storage modulus showed the highest increase in the low frequency region of the modified PLA (ID # 16, 19) added with 0.1 and 1.0 phr of GMA. The maximum value of the combined viscosity of these two samples was 5 times 2.7 times higher than that of pure PLA and initiator modified PLA in the low frequency range.

In addition, the flow curves of these two samples showed that the modified PLA containing 0.1 phr of GMA showed more shear rate dependence. This suggests that the two materials have similar increases in complex viscosity in the low frequency range, but the chain structure that causes them can be different.

That is, as a result of the degree of gelation, it can be seen that the modified PLA containing 1.0 phr of GMA has branched chains, and that the modified PLA containing 0.1 phr of GMA has many crosslinking chains.

Referring to the storage modulus of FIG. 10, in the low frequency region, the GMA 0.1 phr-modified PLA has a storage elastic modulus greater than the value of the GMA 1.0 phr-modified PLA, but a reverse phenomenon occurs in the high frequency region. This means that the molecular weight distribution of the modified PLA containing 0.1 phr of GMA is large, and also indicates that crosslinking and cleavage of the chains of the molecules occur simultaneously. Even when 5 phr of GMA was contained, the composite viscosity was larger than that of pure PLA, and there was no reversal of storage modulus. This means that a lot of GMA was added, but they participated much in the reaction, so that unreacted GMA, which acts as a plasticizer, was reduced.

In FIG. 11, all samples deviate from the pure PLA curve, which means that the branching or crosslinking reaction of the PLA chain proceeded by addition of the initiator. In particular, the slope of the modified PLA containing 0.1 phr of GMA was the lowest due to the effect of crosslinking.

Changes in the physical properties of the samples (ID # 22-28) when the initiator content is added to 0.5 phr are shown in Table 1 and FIGS. 12 to 14.

The largest change was found in the degree of gelation when the content of initiator was 0.5 phr. The gelation degree of PLA with GMA was 3.1% and the gelation degree reached 16%, the highest in PLA containing 0.5 phr of GMA, but decreased with increasing GMA content to 0.1% with 5% GMA. When the GMA content is low and the initiator content is high, the crosslinking reaction is superior to the branching reaction. This increase in crosslinking may contribute to an improvement in melt viscosity, but in practical applications sample preparation may be difficult.

In the present invention, when the GMA produced a sample containing 0.3 and 0.5 phr was operated by reducing the discharge rate to 4kg / hr or less due to the excessive load of the extruder. As the amount of GMA increased, the crosslinking reaction tended to decrease, and when 5% GMA was added, the degree of gelation rapidly decreased to 0.1%. In view of these facts, the addition of GMA seems to affect the branching or high molecular weight linear chain reaction over chain crosslinking, as shown in formula (1).

In FIG. 12, the composite viscosity of the modified PLA containing 0.5 phr of GMA was 7.5 times higher than that of the pure PLA, but as mentioned above, it is judged that there is no practical value due to the excessive load caused by the crosslinking reaction during sample preparation. The complex viscosity of PLA containing 5 phr of GMA is slightly larger than that of pure PLA, but about twice that of PLA modified with initiators only. It is believed that the addition of GMA is beneficial to the branching reaction, but also has the effect of preventing molecular chain cutting due to the initiator.

The storage modulus of FIG. 13 also showed a similar tendency as the composite viscosity.

In the modified Cole-Cole plot of FIG. 14, the curves of all modified PLAs were off the pure PLA line, and the slope of GMA 0.5 phr modified PLA with the highest degree of gelation was smallest. This means that all samples caused branching or crosslinking reactions, and samples with high gelling degree showed that the melt tended to be elastic due to chemical crosslinking.

Biodegradability Results

Biodegradability and biodegradation rate of the polymer are very important physical properties when discarded after being used for single use. This is because if the biodegradable polymer is disposed of together with organic waste such as food waste and subjected to environmentally friendly processes such as composting, the low biodegradation rate and biodegradation may cause fatal defects in the composting process and the processing of finished compost products.

In FIG. 15, the biodegradability of cellulose, which is a reference material, was 85% for 90% pure PLA, and about 85% for PLA modified with only an initiator. The biodegradability of the modified PLA added GMA with high modifying effect was about 5% lower than that of pure PLA. This is because molecular weight was increased due to molecular bonding and crystallinity was increased. However, these modified PLAs are disposed of and disposed of together with organic wastes, which does not affect environmentally friendly processes such as composting.

According to the above experiment, when the amount of the GMA is 0.5 phr or less, the effect is good when the content of the initiator is added 0.1 phr, and when the GMA is included more than 1.0 phr was effective when 0.3 phr is included. When the amount of initiator is more than 0.5 phr, when the amount of GMA is small, the crosslinking reaction greatly increases the compound viscosity and storage modulus, but the extruder load increases rapidly during sample preparation due to the increase in crosslinking. Is not good.

The biodegradability increased with increasing initiator content and was not significantly affected by GMA content.

Therefore, in the experiments of the present invention, PLA modified with 1.0 phr of GMA and 0.3 phr of initiator showed a 5 times higher effect than the composite viscosity of pure PLA, and it is determined that the most effective and practical value.

1 is a graph showing the results of a composite viscosity of modified PLAs containing no functional monomers at 190 ° C. according to frequency (ω).

FIG. 2 is a graph showing the storage modulus of modified PLAs containing no functional monomer at 190 ° C. according to the frequency (ω). FIG.

FIG. 3 shows the Log G ′ vs. concentration of modified PLAs that do not contain functional monomers according to frequency (ω) at 190 ° C. FIG. Log G "plot.

4 is a graph showing the results of complex viscosity of modified PLAs according to the amount of GMA without adding an initiator according to frequency (ω) at 190 ° C.

FIG. 5 shows Log G ′ vs. modified PLAs according to the amount of GMA without initiator addition at 190 ° C. according to frequency (ω). Log G "plot.

Figure 6 is a graph showing the results of the composite viscosity of the modified PLA according to the amount of GMA in the initiator 0.1phr addition conditions according to the frequency (ω) at 190 ℃.

FIG. 7 is a graph showing the storage modulus results of modified PLAs according to the amount of GMA under the conditions of adding 0.1 phr of an initiator according to the frequency (ω) at 190 ° C. FIG.

FIG. 8 shows Log G 'vs. modified PLAs according to the amount of GMA under the condition of adding 0.1 phr of initiator according to the frequency (ω) at 190 ° C. Log G "plot.

9 is a graph showing the results of the composite viscosity of the modified PLA according to the amount of GMA under the 0.3 phr addition conditions of the initiator according to the frequency (ω) at 190 ℃.

FIG. 10 is a graph showing the storage modulus results of modified PLAs according to the amount of GMA under the conditions of adding 0.3 phr of an initiator according to the frequency (ω) at 190 ° C. FIG.

FIG. 11 shows Log G 'vs. modified PLAs according to the amount of GMA under the condition of adding 0.3 phr of initiator according to the frequency (ω) at 190 ° C. Log G "plot.

12 is a graph showing the results of a composite viscosity of modified PLAs according to the amount of GMA under the conditions of adding 0.5 phr of an initiator according to the frequency (ω) at 190 ℃.

FIG. 13 is a graph showing the storage modulus results of modified PLAs according to the amount of GMA under the condition of adding 0.5 phr of an initiator according to the frequency (ω) at 190 ° C. FIG.

FIG. 14 shows Log G 'vs. modified PLAs according to the amount of GMA in the condition of adding 0.5 phr of an initiator according to the frequency (ω) at 190 ° C. Log G "plot.

15 is a graph of biodegradation performed for 70 days under controlled aerobic conditions.

Claims (4)

The host is polylactic acid, A reaction initiator added in an amount of 0.01-0.4% by weight based on the weight of the polylactic acid, 0.01-5% by weight based on the weight of the polylactic acid, and includes a monomer having one epoxy group or a maleic anhydride group or an isocyanate group capable of rapid condensation polymerization and a double bond having one radical reaction as a functional monomer. A high viscosity-modified plant-derived biodegradable resin composition for high magnification foaming, comprising a monomer having an organic nucleating agent, and simultaneously having one reactor capable of condensation polymerization and one reactor capable of radical reaction. According to claim 1, wherein the monomer is glycidyl methacrylate (Glycidyl methacrylate (GMA), 1,2-EPOXY-9-DECENE, 1,2-EPOXY-5-HEXENE, 4-VINYL-1-CYCLOHEXENE- High magnification with the addition of monomers having one reactor capable of condensation polymerization and one reactor capable of radical reaction, characterized by alternatively using 1,2-EPOXIDE, LIMONENE-1,2-EPOXIDE, ALLYL GLYCIDYL ETHER High viscosity modified plant derived biodegradable resin composition for foaming. delete The monomer according to claim 1, wherein at least one initiator is selected from a dialkyl peroxide, which is an initiator of luperox or oxygen peroxide, and one reactor capable of radical polymerization and one reactor capable of radical reaction. High viscosity modified plant-derived biodegradable resin composition for high magnification foaming.

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