Plasticizing of aliphatic polyesters with alkyl esters of dianhydrohexitols

Abstract

A composition includes: at least one aliphatic or semi-aliphatic polyester containing at least 70 mol % of saturated aliphatic units, whereby the units can be obtained by polycondensation of monomers selected from among saturated hydroxyalkanoic acids having formula HO—CxH2x—COOH, saturated dicarboxylic acids having formula HOOC—CxH2x—COOH, and saturated diols having formula HO—CxH2x—OH, wherein x=1-20, preferably 1-6, the rest of the units being formed by aromatic units; and at least one alkyl ester of 1,4:3,6-dianhydro hexitol selected from among alkyl monoesters and alkyl diesters of isosorbide, isomannide and isoidide. A a method for producing one such composition and to the different uses of one such composition are also described.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]A subject matter of the invention is an aliphatic or semi-aliphatic polyester composition plasticized by a specific diol ester. Another subject matter of the invention is a process for manufacturing said composition and uses of this composition. Another subject matter of the invention is the use of this diol ester as plasticizer for an aliphatic or semi-aliphatic polyester.[0003]2. Description of the Related Art[0004]The use of plastics has become widespread in numerous applications. The amounts of plastic which are produced and used worldwide have thus significantly increased in recent years, resulting in an increase in the volume of waste and in environmental problems.[0005]In order to facilitate the removal of this plastic waste, biodegradable polymers are forming the subject of very particular interest.[0006]Mention may be made, as an example of biodegradable polymer, of “biodegradable polyethylene”, which is in rea...

AI Technical Summary

Problems solved by technology

The amounts of plastic which are produced and used worldwide have thus significantly increased in recent years, resulting in an increase in the volume of waste and in environmental problems.

However, these polyesters can exhibit a number of disadvantages.

In particular, their mechanical properties may be insufficient for certain uses.

For example, PLA, in particular highly crystalline PLA, exhibits a very low elongation at break at ambient temperature (of the order of a few percent only) and is thus very brittle.

However, a plasticizer used for a certain type of polymer is not necessarily suitable for another type of polymer.

Glycerol trioleate, glycerol decanoate, propylene glycol, glycerol trihexanoate, glycerol, triacetin, lactates and citrates, which are known plasticizers for polyvinyl chloride (PVC), do not or insufficiently plasticize PLA, are not compatible with PLA or have an insufficient plasticizing effect.

Furthermore, these esters are not very stable thermally and exhibit a high volatility, which brings a significant loss of the plasticizer during the preparation of the plasticized PLA composition.

Thus, none of the current solutions is entirely satisfactory for the plasticization of aliphatic or semi-aliphatic polyesters.

Furthermore, another problem of the products manufactured from these polyesters is the level of sound nuisance which can accompany their use.

This is because, during the handling of the product by the final consumer, the noise created can be very loud, this particularly being the case when said product comprises sheets or films of these polyesters, which are generally the case with packagings.

By way of example, as a result of the dissatisfaction of consumers, Frito Lay® in 2010 had to withdraw bags of chips which they had placed on the American market and which were packaged in material produced from PLA because the noise was too great when the consumer of the chips opened or handled the bag.

Similar problems could also be observed in plants for the manufacture of articles made of PLA, in particular when these objects are obtained by extrusion.