Aliphatic-aromatic copolyesters and their mixtures

Abstract

Aliphatic-aromatic copolyester comprising the repeating units, which comprise a dicarboxylic component and a dihydroxylic component:
[O(R.sub.11)OC(O)(R.sub.13)C(O)]
[O(R.sub.12)OC(O)(R.sub.14)C(O)].
The dihydroxylic component comprises units O(R.sub.11)O and O(R.sub.12)O from diols, wherein R.sub.11 and R.sub.12 individually are selected from C.sub.2-C.sub.14 alkylene, C.sub.5-C.sub.10 cycloalkylene, C.sub.2-C.sub.12 oxyalkylene, heterocycles and mixtures thereof. The dicarboxylic component comprises units C(O)(R.sub.13)C(O) from aliphatic diacids and units C(O)(R.sub.14)C(O) from aromatic diacids, wherein R.sub.13 is C.sub.0-C.sub.20 alkylene and mixtures thereof. The aromatic diacids comprise at least one heterocyclic aromatic diacid of renewable origin, and preferably furandicarboxylic acid. The molar percentage of the aromatic diacids is >90% and <100% of the dicarboxylic component. The aliphatic-aromatic copolyester has appreciable workability, toughness and high values for ultimate tensile strength and elastic modulus. It can be mixed with other polymers.

Claims

1. Aliphatic-aromatic copolyester of a dicarboxylic component and a dihydroxylic component and comprising the following repeating units:
[O(R.sub.11)OC(O)(R.sub.13)C(O)]
[O(R.sub.12)OC(O)(R.sub.14)C(O)] wherein the dihydroxylic component comprises units O(R.sub.11)O and O(R.sub.12)O deriving from a diol, wherein R.sub.11 and R.sub.12 are the same or different and are selected from the group consisting of C.sub.2-C.sub.14 alkylene, C.sub.5-C.sub.10 cycloalkylene, C.sub.2-C.sub.12 oxyalylene, heterocycles and mixtures thereof, wherein the dicarboxylic component consists of units C(O)(R.sub.13)C(O) deriving from an aliphatic diacid selected from the group consisting of succinic acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecandioic acid, dodecandioic acid, brassylic acid, octadecandioic acid and mixtures thereof and units C(O)(R.sub.14)C(O) deriving from 2,5-furandicarboxylic acid of renewable origin and wherein the molar percentage of said 2,5-furandicarboxylic acid is at least 91% and lower than 100% of the dicarboxylic component, and wherein said diol comprises at least 50 mol % of 1,4-butanediol with respect to the total diol content, said aliphatic-aromatic copolyester having a Young's Modulus of at least 1000 MPa after annealing for 12-18 hours in a temperature range of 60-80 C.

2. Aliphatic-aromatic copolyester according to claim 1, wherein the molar percentage of said 2,5-furandicarboxylic acid is between 91 and 99%.

3. Aliphatic-aromatic copolyester according to claim 2, wherein the molar percentage of said 2,5-furandicarboxylic acid is between 92 and 98%.

4. Aliphatic-aromatic copolyester according to claim 1 wherein said aliphatic diacid is of renewable origin.

5. Aliphatic-aromatic copolyester according to claim 1, used in mixture with one or more additional polymers of synthetic or natural origin.

6. Mixture according to claim 5, wherein said one or more additional polymers of synthetic or natural origin is biodegradable.

7. Mixture according to claim 6, wherein said additional biodegradable polymer is a biodegradable polyester of the diacid-diol type, from hydroxyacid or of the polyester-ether type.

8. Mixture according to claim 7, wherein said additional biodegradable polyester of the diacid-diol type is aliphatic.

9. Mixture according to claim 7, wherein said additional biodegradable polyester of the diacid-diol type is aliphatic-aromatic.

10. Mixture according to claim 7, wherein said additional biodegradable polyester from hydroxyacid is selected from the group consisting of poly L lactic acid, poly D lactic acid and stereocomplexed poly D-L lactic, poly--caprolactone, poly hydroxybutyrrate, poly hydroxybutirrate-valerate, poly hydroxybutirrate propanoate, poly hydroxybutirrate-hexanoate, poly hydroxybutirrate-decanoate, poly hydroxybutirrate-dodecanoate, poly hydroxybutirrate-hexadecanoate, poly hydroxybutirrate-octadecanoate, poly 3-hydroxybutirrate 4-hydroxybutirrate.

11. Mixture according to claim 6, wherein said additional polymer of natural origin is selected from the group consisting of starch, cellulose, chitin, chitosan, alginates, proteins, natural rubbers, rosinic acid and its derivatives, lignins as such, purified, hydrolyzed, basified and their derivatives.

12. Mixture according to claim 5, wherein said additional polymer is selected from the group consisting of a polyolefin, a non-biodegradable polyester, a polyester- and polyether-urethan, a polyurethan, a polyamide, a polyaminoacid, a polyether, a polyurea, a polycarbonate and mixture thereof.

13. An article produced from a copolyester according to claim 1 or mixture thereof with one or more additional biodegradable polymers of synthetic or natural origin being selected from the group consisting of: mono- and bi-oriented films, and films multilayered with other polymeric materials; films for use in the agricultural sector; cling films for use with foodstuffs, for bales in agriculture, and for wrapping waste; bags and bin liners for the organic waste collection; thermoformed foodstuff packaging, both mono- and multi-layered; coatings obtained using the extrusion coating method; multilayer laminates with layers of paper, plastic, aluminium, or metallized films; expanded or expandable beads for the production of pieces obtained by sintering; expanded and semi-expanded products; foam sheets, thermoformed foam sheets, and containers obtained from them for use in foodstuff packaging; fruit and vegetable containers in general; composites with gelatinised, destructured and/or complexed starch, natural starch, flours or vegetable or inorganic natural fillers; fibres, microfibers, composite microfibers wherein the core is constituted by rigid polymers and the shell is constituted by said biodegradable polyester, blend composite fibres, fibres with different sections, from circular to multilobed, stample fibres, woven and nonwoven fabrics or spun bonded, melt blown or thermobonded for use in sanitary and hygiene products, and in the agricultural and clothing sectors.

Description

EXAMPLE 1

Synthesis of Polybutylene (Furandicarboxylate-Co-Sebacate) Containing 92% Mol of Butylenefuran Dicarboxylate Units

(1) The following were placed in a 200 ml two-necked glass reaction vessel provided with a Teflon propeller stirrer, a nitrogen connection and a water condenser connected to a distillate collection test tube: Dimethylester of 2,5-furandicarboxylic acid (DMFD): 60.4 g (0.328 moles) Sebacic acid: 5.8 g (0.028 moles) Butanediol: 45.0 g (0.5 moles)
Esterification Stage

(2) The flask was immersed in an oil bath thermostatted to a temperature of 180 C. maintaining stirring at 400 rpm.

(3) Water and methanol were distilled off during the reaction. The distillation was allowed to proceed for 30 minutes after which 100 ppm of tetraorthobutyltitanate (Tyzor TnBT marketed by Dupont) were added as an esterification catalyst and the temperature of the oil bath was gradually raised to 235 C. over a period of 2 hours 30 minutes. The conversion achieved, calculated from the ratio between the quantity of distillates recovered during the reaction and the quantity which could be theoretically obtained from them, was >95%.

(4) Polycondensation Stage

(5) Subsequently the water condenser was replaced with an air condenser provided with a graduated conical-bottom test tube for the collection of distillates and a further 1000 ppm of Tyzor TnBT were added as a polycondensation catalyst. The pressure was reduced to 1 mbar over a period of approximately 10 minutes.

(6) The reaction was then continued for 4 hours raising the oil temperature to 245 C.

(7) A product with an MFR (190 C., 2.16 kg)=12.6 g/10 min was obtained.

(8) The product was analysed using a Perkin Elmer DSC differential scanning calorimeter, yielding the following results: T.sub.m=154 C., H.sub.f=19.0 J/g, T.sub.g=21 C.

(9) The polymer was subsequently characterised with regard to its mechanical properties according to ASTM D638 standard (see Table 1).

EXAMPLE 2

(10) Using equipments and operative conditions according to Example 1a polybutylene (furandicarboxylate-co-sebacate) containing 97% mol of butylenefuran dicarboxylate units has been prepared.

(11) The polymer was characterised with regard to its mechanical properties according to ASTM D638 standard (see Table 1).

COMPARATIVE EXAMPLE 1

(12) Using equipments and operative conditions according to Example 1a polybutylene (furandicarboxylate-co-sebacate) containing 85% mol of butylenefuran dicarboxylate units has been prepared.

(13) The polymer was characterised with regard to its mechanical properties according to ASTM D638 standard (see Table 1).

(14) TABLE-US-00001 TABLE 1 % mol of butylenefuran dicarboxylate units 85 92 97 Yield strength (MPa) 15 24.5 19 Tensile strength (MPa) 51 52 60 Elongation at break (%) 420 380 380 Elastic modulus (MPa) 240 610 600

EXAMPLE 3

(15) The copolyesters according to Example 1 and 2 and Comparative Example 1 have been annealed for 18 hours at 80 C. After annealing the copolyesters were characterized with regard to their mechanical properties according to ASTM D638 standard (see Table 2).

(16) TABLE-US-00002 TABLE 2 % mol of butylenefuran dicarboxylate units 85 92 97 Yield strength (MPa) 23 30 60 Tensile strength (MPa) 57 54 59 Elongation at break (%) 440 360 275 Elastic modulus (MPa) 490 1550 1850