Composite based on polyalkylene carbonate and polyolefin

Abstract

Disclosed is a polyalkylene carbonate and polyolefin-based composite and, more particularly, a composite prepared through reaction of a mixed composition including polyalkylene carbonate, polyolefin, an initiator, and a blending aid, wherein an amount of the polyalkylene carbonate is 60 wt % to 95 wt %, a total amount of the initiator, the blending aid, and the polyolefin is 5 wt % to 40 wt %, and the composite has a matrix-filler morphology in which a matrix formed of the polyalkylene carbonate includes a filler formed of the polyolefin.

Claims

1. A composite prepared through reaction of a mixed composition comprising polyalkylene carbonate, polyolefin, initiator, and blending aid which is mixed with the polyolefin, wherein an amount of the polyalkylene carbonate is 60 wt % to 95 wt %, and a total amount of the initiator, the blending aid, and the polyolefin is 5 wt % to 40 wt %, wherein the composite has a matrix-filler morphology in which a matrix formed of the polyalkylene carbonate includes a filler formed of the polyolefin, wherein the filler is uniformly dispersed in the matrix, wherein the blending aid is selected from a first blending aid having a molecular weight of 20 to 1,000, or a mixture of the first blending aid and a second blending aid having molecular weight of 30,000 to 300,000, and wherein the filler is present in the form of particles in the matrix.

2. The composite according to claim 1, wherein the filler has a particle diameter of 0.1 m to 5 m.

3. The composite according to claim 1, wherein the article has an Izod impact strength of 7 kg.Math.cm/cm or more.

4. The composite according to claim 1, wherein the composite exhibit non-stickiness at a temperature of 50 C. to 90 C., in terms of stickiness in a pellet state.

5. The composite according to claim 1, wherein the article has a tensile elongation at break point of 300% or more.

6. The composite according to claim 1, wherein the article has a yield tensile strength of 400 kg/cm.sup.2 or more.

7. The composite according to claim 1, wherein the polyalkylene carbonate is polyethylene carbonate (PEC) and/or polypropylene carbonate (PPC).

8. The composite according to claim 1, wherein the first blending aid is one or a mixture of at least two selected from the group consisting of vinyltrimethoxy silane, vinyl-tris(beta-methoxyethoxy)silane, vinyltriacetoxy silane, vinyltrismethoxyethoxy silane, gamma-(meth)acryloxypropyltriethoxy silane, vinyltriethoxy silane, and gamma-(meth)acryloxypropyltrimethoxy silane; and acrylic acid, fumaric acid, methacrylic acid, crotonic acid, maleic acid, itaconic acid, sorbic acid, and anhydrides thereof.

9. The composite according to claim 1, wherein the second blending aid is ethylene-ethylacrylate copolymer modified with maleic anhydride.

10. The composite according to claim 1, wherein the mixed composition further comprises a polymer having miscibility with the polyalkylene carbonate to enhance miscibility among the components.

11. The composite according to claim 10, wherein an amount of the miscible polymer is 1 wt % to 30 wt % based on a total weight of the mixed composition.

12. The composite according to claim 10, wherein the polymer is one or a mixture of at least two selected from the group consisting of cellulose acetate propionate (CAP), cellulose acetate butyrate (CAB), polyamide (PA), polylactic acid (PLA), polybutylene succinate (PBS), polyvinyl acetate (PVAc), polymethyl methacrylate (PMMA), ethylene vinyl alcohol (EVOH), polyvinyl alcohol (PVA), polycarbonate (PC), and ionomer-based polymers.

13. A molded product comprising the composite according to claim 1.

14. A molded product comprising the composite according to claim 12.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawing, in which:

(2) FIG. 1 is a scanning electron microscope (SEM) image of a composite obtained according to Example 1 through reaction of a mixture of polyalkylene carbonate and polyolefin;

(3) FIG. 2 is an SEM image of a composite obtained according to Example 2 through reaction of a mixture of polyalkylene carbonate and polyolefin;

(4) FIG. 3 is an SEM image of a composite obtained according to Comparative Example 1 through reaction of a mixture of polyalkylene carbonate and polyolefin; and

(5) FIG. 4 is an SEM image of a composite obtained according to Comparative Example 2 through reaction of a mixture of polyalkylene carbonate and polyolefin.

BEST MODE

(6) Now, the present invention will be described in more detail with reference to the following examples. These examples are provided for illustrative purposes only and should not be construed as limiting the scope and spirit of the present invention.

EXAMPLE 1

(7) 100 parts by weight of polyethylene (PE), 0.1 parts by weight of dicumyl peroxide as an initiator, and 1 part by weight of maleic anhydride having a molecular weight of 98 as a first blending aid were mixed using a super mixer, and 80 wt % of polypropylene carbonate was added to 20 wt % of the resultant mixture and melt-blended in a twin-screw extruder. The composite was subjected to injection molding to manufacture a molded product.

EXAMPLE 2

(8) A molded product was manufactured in the same manner as in Example 1, except that maleic anhydride as a first blending aid was used in combination with 10 parts by weight of a modified maleic anhydride of ethylene-ethylacrylate copolymer having a molecular weight of about 120,000 as a second blending aid.

EXAMPLE 3

(9) 100 parts by weight of PE, 0.1 parts by weight of dicumyl peroxide as an initiator, 1.5 parts by weight of maleic anhydride as a first blending aid, and 10 parts by weight of a zinc ionomer, which is a miscible polymer, were mixed using a super mixer, and 80 wt % of polypropylene carbonate was added to 20 wt % of the resultant mixture and melt-blended in a twin-screw extruder. The composite was subjected to injection molding to manufacture a molded product.

EXAMPLE 4

(10) 100 parts by weight of PE modified with maleic anhydride, 0.1 parts by weight of dicumyl peroxide as an initiator, and 1 part by weight of trimethoxy silane as a first blending aid were mixed using a super mixer, and 80 wt % of polypropylene carbonate was added to 20 wt % of the resultant mixture and melt-blended in a twin-screw extruder. The composite was subjected to injection molding to manufacture a molded product.

COMPARATIVE EXAMPLE 1

(11) A molded product was manufactured in the same manner as in Example 1, except that only 80 wt % of polypropylene carbonate was added to 20 wt % of PE and blended.

COMPARATIVE EXAMPLE 2

(12) A molded product was manufactured in the same manner as in Example 1, except that the maleic anhydride as a first blending aid was not used and 10 parts by weight of ethylene-ethylacrylate copolymer modified with maleic anhydride as a second blending aid was used.

EXPERIMENTAL EXAMPLE 1

(13) Each of the mixtures prepared in Examples 1 and 2 and Comparative Examples 1 and 2 was subjected to reaction to prepare a polymer resin, and morphology of each composite was observed using a scanning electron microscope (SEM). Images taken using the SEM are illustrated in FIGS. 1 to 4. Referring to FIGS. 1 to 4, it can be confirmed that the composite of Examples 1 and 2 have a structure in which polyolefin is dispersed in polyalkylene carbonate in the form of particles with uniform size and there is no phenomenon in which the polyolefin escapes therefrom due to excellent miscibility with the polyalkylene carbonate, while the polymer resins of Comparative Examples 1 and 2 have a structure in which polyolefin escapes from polyalkylene carbonate as a matrix due to non-mixing of the polyolefin and the polyalkylene carbonate and the size of polyolefin domain is also not uniform.

(14) In particular, in the composite of Comparative Example 2, although the second blending aid is included, the size of the polyolefin domain is not uniform and the polyolefin escapes from the polyalkylene carbonate due to poor miscibility therewith. This is because the polymer resin including the second blending aid alone has an unstable mixed phase and thus a particular morphology with excellent mechanical strength is not formed.

EXPERIMENTAL EXAMPLE 2

(15) Each of the molded products of Examples 1 to 4 and Comparative Examples 1 and 2 was cut to a size of 10 cm10 cm to construct a sample, and tensile elongation at break point, yield tensile strength, Izod impact strength, and stickiness of each sample were measured. Results are shown in Table 1 below.

(16) TABLE-US-00001 TABLE 1 Tensile Yield elongation tensile Izod impact at break strength strength Stickiness point (%) (kg/cm.sup.2) (kg .Math. cm/cm) 50 C. 90 C. Comparative 140 290 2.1 stickiness stickiness Example 1 Comparative 160 340 2.5 stickiness stickiness Example 2 Example 1 310 420 7.1 Non-stick- Non-stick- iness iness Example 2 320 410 8.5 Non-stick- Non-stick- iness iness Example 3 370 430 15.0 Non-stick- Non-stick- iness iness Example 4 340 410 12.0 Non-stick- Non-stick- iness iness * Stickiness is obtained by measuring stickiness between pellets after performing aging in an oven at 50 C. and 90 C. for 1 hour.

(17) As shown in Table 1 above, it can be confirmed that the composite of Examples 1 to 4 exhibit excellent tensile elongation at break point, yield tensile strength and Izod impact strength and significantly enhanced adhesion between pellets as compared to the composite of Comparative Examples 1 and 2.

(18) In addition, it can be confirmed that, when a second blending aid is used alone as in Comparative Example 2, desired mechanical/physical properties may not be obtained. This is because formation of the matrix-filler morphology is unstable when using a second blending aid alone and thus the polyolefin does not properly function as a reinforcing agent.

(19) Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

INDUSTRIAL APPLICABILITY

(20) As described above, in a composite according to the present invention, a composite further includes particular components in addition to polyalkylene carbonate and polyolefin exhibits high miscibility. In addition, the composite includes particular amounts of the polyalkylene carbonate, the polyolefin, and other particular components and thus has a specific morphology, whereby excellent physical properties of the two resins are exhibited and mechanical characteristics, in particular tensile strength and impact strength, are enhanced and stickiness is enhanced.