Further, the polylactic resin is one of poly-L-lactic acid resin and poly-D-lactic acid resin, and the melting temperature of the polylactic acid resin is less than or equal to 140 ℃.

Furthermore, the toughening agent is methyl methacrylate-butadiene-styrene copolymer with the particle size of 250-350 nm.

The preparation method of the high impact polycarbonate/polylactic acid resin composition comprises the following steps:

premixing polycarbonate resin, polylactic resin, E-MA-GMA copolymer, EBA copolymer, toughening agent and ester exchange catalyst according to a proportion;

and putting the premix into a double-screw extruder for melt blending to obtain the composition.

Further, the double-screw extruder is provided with a feed inlet and a mouth die, and the premix enters the double-screw extruder from the feed inlet and is then discharged from the mouth die;

the temperature of the material cylinder between the feed inlet and the neck mold of the double-screw extruder is arranged in a ladder shape, and the temperature of the ladder is arranged in sequence as follows: 100 deg.C, 120 deg.C, 200 deg.C, 210 deg.C, 220 deg.C, 230 deg.C, 180 deg.C, 150 deg.C.

The invention has the beneficial effects that:

in the formula system of the high impact resistant polycarbonate/polylactic acid resin composition, the E-MA-GMA copolymer and the EBA copolymer are used as compatilizers, the vinyl copolymer with reactive functional groups and the vinyl copolymer without the functional groups are compounded and used according to a certain proportion, the interface compatibility between the polycarbonate and the polylactic acid can be obviously improved, meanwhile, a certain ester exchange catalyst is used for promoting the ester exchange reaction between the polycarbonate and the polylactic acid to generate copolyester, a specific toughening agent is used for toughening the main phase of the polycarbonate, the flexibility and the deformability of the base material phase are improved, and the polycarbonate/polylactic acid resin composition with excellent chemical resistance and impact resistance can be prepared.

According to the invention, the polycarbonate resin and the polylactic acid resin are combined, and the specific compatilizer is used, so that the composition can realize advantage complementation, not only can the defect of poor solvent resistance of the polycarbonate resin be improved, but also the impact property and the heat resistance of the polylactic acid can be improved, and the application field of the polylactic acid is expanded. Meanwhile, the resin composition realizes partial degradation function, and reduces the burden of the environment.

Detailed Description

The technical solution of the present invention will be further described with reference to the accompanying embodiments.

The invention provides a high impact polycarbonate/polylactic acid resin composition, which comprises the following components in parts by weight:

E-MA-GMA, i.e., ethylene-methyl acrylate-glycidyl methacrylate, EBA ethylene-butyl acrylate, polycarbonate resin, i.e., PC resin, polylactic acid resin, i.e., PLA resin.

Ethylene in the E-MA-GMA is a flexible molecule, an epoxy functional group in the GMA can react with a terminal hydroxyl group of PC and a terminal hydroxyl group or a terminal carboxyl group in PLA, and an acrylic acid in the E-MA-GMA is similar to the structures of PC and PLA and further plays a role in compatibilization; EBA is mainly due to the similarity of domains PLA and PC, which serve as physical compatibilization. Meanwhile, a part of efficient ester exchange catalyst is added into the system to further catalyze the ester exchange reaction between PC and PLA to generate copolyester, so that the compatibility of PC and PLA is further increased. More importantly, the ethylene segments in E-MA-GMA and EBA impart excellent chemical resistance to PC.

Further, the weight ratio of the E-MA-GMA copolymer to the EBA copolymer is 1:1-2: 1. Based on the mechanism, the weight ratio of the E-EMA-GMA with the reactive functional group in the system is more than that of the EBA, so that the E-EMA-GMA with the reactive functional group can be induced to react with the PC and the PLA to generate the copolyester, and the compatibility of the PC and the PLA is increased; however, from the economical point of view, it is not preferable to add too much E-EMA-GMA copolymer. The two compatilizers are in the weight ratio range, so that the PC and the PLA have good compatibility.

Further, the transesterification catalyst is tetrabutyl titanate. The catalyst has the characteristic of high efficiency.

Further, the polycarbonate resin is bisphenol A type polycarbonate, and the number average molecular weight is 20000-30000 g/mol. When the molecular weight of the PC is too low, the molecular chains which are not long enough and are too many have more chances to be oriented and broken on the interface and to have ester exchange reaction with the polylactic acid; the molecular weight of PC is too high, and the molecular chain does not have enough mobility, so that the ester exchange reaction is also influenced. The polycarbonate resin in the molecular weight range has proper molecular chains and enough migration capacity, and ensures that the ester exchange reaction is smoothly carried out.

Further, the polylactic resin is one of poly-L-lactic acid resin and poly-D-lactic acid resin, and the melting temperature of the polylactic acid resin is less than or equal to 140 ℃. The melting temperature of PLA in the present invention is required to be close to the glass transition temperature of PC so that the processing temperature can be driven to a more suitable temperature.

Furthermore, the toughening agent is methyl methacrylate-butadiene-styrene copolymer with the particle size of 250-350 nm. The resin composition takes PC as a main phase, the PC is a tough base material, and if the grain diameter of the toughening agent is too large, the PC resin is not suitable to be toughened; the grain size is too small, the toughening agent is not easy to disperse in the composition, and agglomeration is easy to cause, so that the toughening effect cannot be achieved. The grain size of the toughening agent is set to be 250-350nm, so that the toughening effect is better, the methyl methacrylate-butadiene-styrene copolymer is used as the toughening agent, the toughening effect on PC resin is better, and the flexibility and the deformability of the base material phase are improved.

The invention adopts a one-step method to prepare the polycarbonate/polylactic acid resin composition, and the process is simple and easy to control.

The temperature of the feeding section is set to be 100 ℃ and 120 ℃ which are lower than the melting point of PLA and the Tg (plastic glass transition temperature) of PC, so that the feeding blockage caused by bridging at a feeding port due to the melting of particles at the feeding section is avoided; while the temperature near the die was set at 180 ℃ and 150 ℃ in order to avoid or reduce thermal degradation of the PLA material, thereby obtaining a high-quality polycarbonate/polylactic acid resin composition.

The invention is further illustrated by the following examples and comparative examples.

In the following examples, the PC resin was designated 1100, manufactured by korea, le day;

PLA resin, the mark is REVODE101L, the melting point is less than or equal to 135 ℃, MI (190 ℃ is 2.16) is 5-10 g/10min, and is made of Zhejiang sea vital biological materials, wherein MI is the melt index;

E-EMA-GMA copolymer, having the designation AX8900, manufactured by Acoma, France;

EBA copolymer, No. 35BA40, manufactured by arkema, france;

the toughening agent MBS is of EM500, the grain size of the toughening agent is about 250nm, and the toughening agent is chemically manufactured by LG;

the transesterification catalyst was tetrabutyl titanate, commercially available.

Examples 1 to 5 each provide a high impact polycarbonate/polylactic acid resin composition and a method for preparing the same, the components of each example being used in the amounts shown in table 1 in parts by weight, the method comprising the steps of:

(1) weighing polycarbonate resin, polylactic acid resin, E-MA-GMA copolymer, EBA copolymer, toughening agent and ester exchange catalyst according to the weight parts in the table 1;

(2) premixing the weighed raw materials;

(3) and (3) putting the premix into a double-screw extruder from a feed inlet at one time for melt blending to obtain the composition.

The double-screw extruder is provided with a feed inlet and a mouth die, premix enters the double-screw extruder from the feed inlet and is then discharged from the mouth die, and the length/diameter ratio of a screw of the double-screw extruder is 40; the feed cylinder temperature is the echelonment setting between double screw extruder's charge door and the bush, and the temperature setting of this ladder does in proper order: 100 deg.C, 120 deg.C, 200 deg.C, 210 deg.C, 220 deg.C, 230 deg.C, 180 deg.C, 150 deg.C.

Comparative examples 1 to 5

Comparative examples 1 to 5 each provide a carbonate/polylactic acid resin composition, each component and part by weight of which are shown in table 1; the resin polymers in comparative examples 1 to 5 were prepared in the same manner as in examples 1 to 5.

The resin polymers of comparative examples 1 to 5 are different in formulation from those of examples 1 to 5 in that:

the formulation of the resin composition of comparative example 1 did not contain a reactive compatibilizer E-MA-GMA copolymer;

the resin composition of comparative example 2 did not contain a non-reactive compatibilizer EBA copolymer;

the weight fraction ratio of E-MA-GMA copolymer/EBA copolymer in the resin composition of comparative example 3 was 1: 2;

the resin composition of comparative example 4 did not contain the toughening agent MBS;

the toughening agent employed in the resin composition of comparative example 5 was a core-shell elastomer (ACR-MMA) whose core layer was a polyacrylic resin;

comparative example 6 did not contain the transesterification catalyst tetrabutyl titanate;

comparative example 7 contained no E-MA-GMA copolymer and EBA copolymer.

Performance testing

The pellets of the resin compositions of examples 1 to 5 and comparative examples 1 to 7 were vacuum-dried at 100 ℃ for 12 hours or more, and then injection-molded into a bar under the same injection molding conditions in accordance with ASTM standards, to test the physical properties of the respective resin compositions.

The test follows the following test method:

the heat distortion temperature is measured based on the test program GB/T1630-2008, and the load is 0.45 MPa;

testing the impact strength of the A-type notch based on a testing procedure of GB/T1843-2008;

the tensile strength and elongation at break were determined on the basis of the test procedure of GB/T1040-2006, the tensile speed being 50 mm/min.

The chemical resistance of the bars was tested based on the 1/4 ellipsometry: fixing the sample strip in a fixture with a certain deflection degree, uniformly coating hand cream on the surface of the sample strip, covering the sample strip with gauze, coating the sample strip once every 24 hours, and observing the appearance change of the sample strip.

TABLE 1

The technical principle of the present invention is described above in connection with specific embodiments. The description is made for the purpose of illustrating the principles of the invention and should not be construed in any way as limiting the scope of the invention. Based on the explanations herein, those skilled in the art will be able to conceive of other embodiments of the present invention without inventive effort, which would fall within the scope of the present invention.

Claims

1. A high impact polycarbonate/polylactic acid resin composition is characterized by comprising the following components in parts by weight:

2. the high impact polycarbonate/polylactic acid resin composition according to claim 1, wherein the weight ratio of the E-MA-GMA copolymer to the EBA copolymer is 1:1 to 2: 1.

3. The high impact polycarbonate/polylactic acid resin composition according to claim 1, wherein the transesterification catalyst is tetrabutyl titanate.

4. The high impact polycarbonate/polylactic acid resin composition as defined in claim 1, wherein the polycarbonate resin is bisphenol A polycarbonate having a number average molecular weight of 20000-30000 g/mol.

5. The high impact polycarbonate/polylactic acid resin composition according to claim 1, wherein the polylactic acid resin is one of poly-L-lactic acid resin and poly-D-lactic acid resin, and the melting temperature of the polylactic acid resin is 140 ℃ or lower.

6. The high impact polycarbonate/polylactic acid resin composition as claimed in claim 1, wherein the toughening agent is a methylmethacrylate-butadiene-styrene copolymer with a particle size of 250-350 nm.

7. The method for preparing a high impact polycarbonate/polylactic acid resin composition according to any one of claims 1 to 6, comprising the steps of:

8. The method of claim 7, wherein the twin-screw extruder has a feed port and a die, and the premix is fed into the twin-screw extruder from the feed port and then discharged from the die;