TRANSPARENT AND HEAT-RESISTANT POLYCARBONATE COMPOSITE AND PREPARATION METHOD THEREOF

Abstract

A transparent and heat-resistant polycarbonate (PC) composite and a preparation method thereof. The PC composite is a blend of a PC, a polyarylester (PAR) and an organic salt. The preparation method includes: drying the PC and the PAR each under vacuum at 80-120 C. for 24-48 h; adding the dried PC, the dried PAR and the organic salt into a melt blending device at a mass ratio of (60-90):(40-10):(0.3-3), and performing melt blending at 250-300 C. to obtain a mixture; and discharging the mixture from the melt blending device, and cooling to normal temperature to obtain a PC composite.

Claims

1. A transparent and heat-resistant polycarbonate (PC) composite, comprising: a blend of a PC, a polyarylester (PAR) and an organic salt, wherein a mass ratio of the PC, the PAR and the organic salt is (60-90):(40-10):(0.3-3).

2. The transparent and heat-resistant PC composite according to claim 1, wherein the organic salt has a metal cation.

3. The transparent and heat-resistant PC composite according to claim 1, wherein the organic salt has an anion of (CF.sub.3SO.sub.2).sub.2N.sup., PF.sub.6.sup., BF.sub.4.sup., Br.sup., Cl.sup., I.sup., NO.sub.3.sup. or CF.sub.3CO.sup.2.

4. The transparent and heat-resistant PC composite according to claim 2, wherein the organic salt is lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI).

5. The transparent and heat-resistant PC composite according to claim 3, wherein the organic salt is lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI).

6. The transparent and heat-resistant PC composite according to claim 1, wherein a mass ratio of the PC, the PAR and the organic salt is 60:40:0.5.

7. A method for preparing a transparent and heat-resistant polycarbonate (PC) composite comprising a blend of a PC, a polyarylester (PAR) and an organic salt, the method comprising: drying the PC and the PAR each under vacuum at 80-120 C. for 24-48 h; adding the dried PC, the dried PAR and the organic salt into a melt blending device at a mass ratio of (60-90):(10-40):(0.3-3), and performing melt blending at 250-300 C. to obtain a mixture; and discharging the mixture from the melt blending device, and cooling to normal temperature to obtain a PC composite.

8. The method according to claim 7, wherein the organic salt has a metal cation.

9. The method according to claim 7, wherein the organic salt has an anion of (CF.sub.3SO.sub.2).sub.2N.sup., PF.sub.6.sup., BF.sub.4.sup., Br.sup., Cl.sup., I.sup., NO.sub.3.sup. or CF.sub.3CO.sup.2.

10. The method according to claim 8, wherein the organic salt is lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI).

11. The method according to claim 9, wherein the organic salt is lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI).

12. The method according to claim 7, wherein a mass ratio of the PC, the PAR and the organic salt is 60:40:0.5.

13. The method according to claim 7, wherein the melt blending device is an internal mixer; the rotor speed of the internal mixer is 40-60 rpm/min during blending, and the melt blending time is 3-10 min.

14. The method according to claim 7, wherein the melt blending device is a single screw extruder; the screw speed of the screw extruder is 15-20 rpm/min during feeding and 45-75 rpm/min during extrusion.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0026] FIG. 1 is a dynamic thermal analysis (DTA) diagram of a material prepared in Comparative Example 1 and Example 2-1;

[0027] FIG. 2 is a thermogravimetric analysis (TGA) diagram of a material prepared in Comparative Example 1 and Example 2-1 under a nitrogen atmosphere; and

[0028] FIG. 3 is a differential thermogravimetric analysis (DTGA) diagram of a material prepared in Comparative Example 1 and Example 2-1.

DETAILED DESCRIPTION

[0029] The present invention is further analyzed below with reference to the accompanying drawings and specific examples.

COMPARATIVE EXAMPLE 1

[0030] Step (1): dry a polycarbonate (PC) and a polyarylester (PAR) each under vacuum at 120 C. for 24 h.

[0031] Step (2): add 36 g of dried PC and 24 g of dried PAR into an internal mixer, and perform melt blending for 10 min at 260 C. and 50 rpm/min.

[0032] Step (3): discharge a mixture from the melt blending device, and cool to normal temperature to obtain a PC/PAR composite.

[0033] A mass ratio of the PC to the PAR in the PC composite prepared in Comparative Example 1 is 60:40.

EXAMPLE 2-1

[0034] Step (1): dry a PC and a PAR each under vacuum at 120 C. for 24 h, where Li-TFSI does not need drying.

[0035] Step (2): add 36 g of dried PC, 24 g of dried PAR and 0.3 g of Li-TFSI into an internal mixer, and perform melt blending for 10 min at 260 C. and 50 rpm/min.

[0036] Step (3): discharge a mixture from the melt blending device, and cool to normal temperature to obtain a PC composite.

[0037] A mass ratio of the PC, the PAR and the Li-TFSI in the PC composite prepared in Example 2-1 is 60:40:0.5.

[0038] The thermal performance of the materials prepared in Comparative Example 1 and Example 2-1 was tested.

[0039] The light transmittance and haze of the materials prepared in Comparative Example 1 and Example 2-1 were tested by pressing a sample into a 0.3 mm sheet.

[0040] Table 1 Glass transition temperature of materials prepared in Comparative Example 1 and Example 2-1

TABLE-US-00001 Sample T.sub.g( C) Comparative Example 1 163.3 196.7 Example 2-1 168.2

[0041] Table 2 Light transmittance of materials prepared in Comparative Example 1 and Example 2-1

TABLE-US-00002 Sample Light transmittance (%) Haze (%) Comparative Example 1 86.1 44.2 Example 2-1 89.8 2.9

[0042] The thermal performance test results are shown in Table 1. According to Tables 1 and 2, the simply melt PC/PAR blend had poor miscibility. The material showed two glass transition temperatures and appeared as an opaque white material. After the Li-TFSI was added, the miscibility of the material was improved. The material showed only one glass transition temperature, and the material appeared as colorless and transparent. This proved that the addition of the Li-TFSI significantly improved the miscibility of the PC/PAR, greatly improved the transparency of the composite, and met the standards of light-transmitting materials required by the industry.

[0043] Table 3 Heat-resistance test results of materials prepared in Comparative Example 1 and Example 1-2 under nitrogen atmosphere

TABLE-US-00003 Sample T.sub.5% ( C) T.sub.max ( C) Comparative Example 1 410.8 447.2 Example 2-1 421.2 486.3

[0044] The heat resistance test results are shown in FIG. 2 and FIG. 3. The initial degradation temperature (T.sub.5%) of the simply melt PC/PAR blend (Comparative Example 1) was 410.8 C., and the temperature corresponding to a maximum thermal weight loss (T.sub.max) was 447.2 C., showing that the simply melt PC blend had a certain heat-resistant temperature. After the addition of the Li-TFSI, the T.sub.5% of the blend increased by 10.4 C., and the T.sub.max increased by 39.1 C., which proved that the addition of the Li-TFSI greatly improved the thermal stability and heat resistance of the PC blend.

EXAMPLE 2-2

[0045] Step (1): dry a PC and a PAR each under vacuum at 120 C. for 24 h, where Li-TFSI does not need drying.

[0046] Step (2): add 42 g of dried PC, 18 g of dried PAR and 0.3 g of Li-TFSI into an internal mixer, and perform melt blending for 10 min at 260 C. and 50 rpm/min.

[0047] Step (3): discharge a mixture from the melt blending device, and cool to normal temperature to obtain a PC composite with high light transmittance.

[0048] A mass ratio of the PC, the PAR and the Li-TFSI in the PC composite prepared in Example 2-2 is 70:30:0.5.

EXAMPLE 2-3

[0049] Step (1): dry a PC and a PAR each under vacuum at 120 C. for 24 h, where Li-TFSI does not need drying.

[0050] Step (2): add 48 g of dried PC, 16 g of dried PAR and 0.3 g of Li-TFSI into an internal mixer, and perform melt blending for 10 min at 250 C. and 40 rpm/min.

[0051] Step (3): discharge a mixture from the melt blending device, and cool to normal temperature to obtain a PC composite with high light transmittance.

[0052] A mass ratio of the PC, the PAR and the Li-TFSI in the PC composite prepared in Example 2-3 is 80:20:0.5.

EXAMPLE 2-4

[0053] Step (1): dry a PC and a PAR each under vacuum at 120 C. for 24 h, where Li-TFSI does not need drying.

[0054] Step (2): add 54 g of dried PC, 6 g of dried PAR and 0.3 g of Li-TFSI into an internal mixer, and perform melt blending for 3 min at 260 C. and 60 rpm/min.

[0055] Step (3): discharge a mixture from the melt blending device, and cool to normal temperature to obtain a PC composite with high light transmittance.

[0056] A mass ratio of the PC, the PAR and the Li-TFSI in the PC composite prepared in Example 2-4 is 90:10:0.5.

EXAMPLE 2-5

[0057] Step (1): dry a PC and a PAR each under vacuum at 120 C. for 24 h, where Li-TFSI does not need drying.

[0058] Step (2): add 36 g of dried PC, 24 g of dried PAR and 0.18 g of Li-TFSI into an internal mixer, and perform melt blending for 10 min at 300 C. and 50 rpm/min.

[0059] Step (3): discharge a mixture from the melt blending device, and cool to normal temperature to obtain a PC composite with high light transmittance.

[0060] A mass ratio of the PC, the PAR and the Li-TFSI in the PC composite prepared in Example 2-5 is 60:40:0.3.

EXAMPLE 2-6

[0061] Step (1): dry a PC and a PAR each under vacuum at 100 C. for 48 h, where Li-TFSI does not need drying.

[0062] Step (2): add 36 g of dried PC, 24 g of dried PAR and 1.8 g of Li-TFSI into a single screw extruder for melt blending at 280 C. to obtain a mixture, the screw speed of the screw extruder being 10 rpm/min during feeding and 45 rpm/min during extrusion; and

[0063] Step (3): discharge the mixture from the melt blending device, and cool to normal temperature to obtain a PC composite.

[0064] A mass ratio of the PC, the PAR and the Li-TFSI in the PC composite prepared in Example 2-6 is 60:40:3.

[0065] The above examples are not intended to limit the present invention, and various changes derived from these examples without creative efforts should fall within the protection scope.