Field of the invention

The present invention relates to a group of plasticisers that at are least partly and preferably fully biobased and de gradable in nature and that are suitable for mixing with other resins to modify their mechanical, physical and chemi cal performance, in particular improving their elongation at break, flexibility, impact strength and fracture toughness. The invention also relates to resin blends comprising said plasticisers and products manufactured from said blends.

Background of the invention

Polymers are an integrated part of daily life products and their application areas continue to increase. Currently, pol ymers are almost exclusively produced from fossil sources, which creates two environmental issues. First, after end of life, incineration of polymers releases CO ₂ , which contrib utes to increasing atmospheric CO ₂ levels. Second, most of these fossil-based polymers lack biodegradability and thus if the polymers are not collected for incineration or recycling, they end up in nature as waste polluting oceans, forests, and recreational areas. Further, polymers can comprise molecules with a harmful effect on human health such as endocrine dis- ruptors as bisphenols and phthalates. Avoiding or reducing these effects on the environment and human health is desira ble.

To combat the environmental issues of polymers, bio-based and biodegradable polymers have gradually been introduced during the last decade. Some of the introduced polymers aim to mimic the chemical structure of fossil-based polymers such as bio based polyethylene whereas other polymers have structures not found in commercially available polymers derived from fossil sources. Examples of such polymers include poly lactic acid, also known as poly lactide and PLA, poly hydroxyalkanoates, poly glycolide, and lignin-based polymers. The structural difference to fossil-based polymers leads to different prop erties of the polymers as exemplified by PLA that lacks the toughness, impact strength, and elongation at break seen among many fossil-based polymers. This implies that PLA can not be used as a direct substitute for fossil-based polymers in many applications, which limits the introduction of PLA and other bio-based resins into said applications.

A cost-effective and scalable approach to modify the proper ties of a resin is melt blending in which the resin is blended with one or more polymers, oligomers or monomers, also broadly known as modifiers, to yield a new resin taking characteristics of each of its constituents. The efficiency of the introduced substance improves when the blended compo nents are miscible. Thus, an advantageous approach to modify the properties of resins is to melt blend them with compounds that are soluble in the resin.

Another advantage of using miscible modifiers instead of im miscible alternatives is the effect on the migration of modi fiers from the resin matrix to the specimen exterior. The mi gration can be decreased by creating a strong compatibility between resin and modifier and can be further enhanced by in creasing the molecular weight of the modifiers, as the migra tion speed is negatively related to molecular weight.

The application area of bio-based and biodegradable resins can advantageously be expanded by melt blending these resins with compounds capable of increasing the elongation at break, flexibility, impact strength, toughness, resilience, melting point, glass transition temperature and/or other properties. To maintain the environmental benefit of the bio-based res ins, the compounds said resins are blended with should pref erably be both bio-based and biodegradable and free of sub stances harmful to humans, plants, and wild-life. US2017066901 discloses a polyester plasticizer made from ke- toglutaric acid and a dialcohol. The exemplified polyester has a molecular weight of 1893 g/mol. US2007203275 discloses mono- and diesters made from propanediol and a monoacid, which causes the synthesized esters to be of low molecular weight. WO2015142584 discloses plasticising diesters made from side streams from bioethanol production and since the plasticizer is a diester, the molecular weight is low. EP2202267 discloses a group of diesters suitable for plasti cizing aliphatic polyester resins. Low molecular weights of the plasticiser can be disadvantageous since this can lead to modifier migration in the blended resin.

EP1564234A1 describes a plasticizer prepared from 2-methyl- 1,3-propanediol, 3-methyl-l,5-pentanediol, adipic acid, and a chain terminator in the form of a monovalent alcohol or acid. Additional aliphatic diol and diacids are present in some em bodiments. The plasticiser is prepared for chlorine-contain ing resins and it is claimed that if the plasticiser obtains a molecular weight above 5000 g/mol its flexibility will de teriorate .

WO2013142534 discloses plasticising esters synthesized from either furoic acid, furfural, or furfuryl alcohol and a car boxylic acid or alcohol. In CN109796626, a plasticizer is prepared from furan dicarboxylic acid and polyethylene glycol or polypropylene glycol. As an aromatic structure, furans are less likely to migrate than aliphatic compounds of similar size, but aromatics are rigid and therefore not well suited for providing toughness and elongation to resins.

US2009253871 discloses a copolymer plasticiser consisting of a compatibilising unit and a plasticising unit. The plasti cising unit is made from alcohol, diacid, and an aromatic structure and according to the above, the addition of aro matic structures is disadvantageous for the plasticizing ef- feet of the unit. Further, due to the need of a compatibilis- ing unit, a larger amount of the copolymer is needed to ob tain the desired plasticizing effect compared to plasticisers that are compatible with the resin.

W02013/119450 prepares a copolymer plasticiser for PLA con sisting of a plasticising unit prepared from glycerol, maleic anhydride and di(ethylene glycol)and a compatibilising unit prepared from lactic acid or lactide.

CN103524721 describes the production of plasticisers from bi oethanol waste streams containing glycol, polyol, and poly saccharides to which polyacids are added to yield a yellow- brown oil. Owing to the variation in the bioethanol side stream, the chemical structure of the plasticizer is hard to control and a plasticizer with colour is likely obtained, which is disadvantageous for some applications.

CN105175697 discloses a two-step procedure to prepare a plas ticiser for polyester resins. In the first step, vegetable oil and glycol are reacted in molar ratio of 1:2-2.5 for 2-8 hours to yield a glyceride intermediate. In the second step, the intermediate is reacted with a diacid or acid anhydride for 6-12h upon which a monoalcohol is added. Sebacic acid is exemplified as a suitable diacid. Vegetable oils commonly consist of fatty acids with carbon chains with a length of 8- 16 units and sebacic acid has 8 carbon atoms, which implies that the synthesized molecule has long carbon segments that have limited solubility in polyester resin with shorter car bon linkages between the ester bonds. Further the two-step procedure and long reaction time is disadvantageous. CN105085883 also uses a two-step procedure by initially pre paring two prepolymers each consisting of adipic acid and a dialcohol and the prepolymers are later reacted to yield a plasticizer. In addition to long reaction time, a molar ex cess of 10-30 % of adipic acid to alcohol is used, which lim its the molecular weight. CN107022067 discloses an isosorbide polyetherester prepared via a two-step reaction in which isosorbide is initially re acted with a dicarboxylic acid. Upon completion of the reac tion between the isosorbide and dicarboxylic acid, a molecule containing an ether group and a single hydroxyl group is added to yield molecule suitable for plasticizing PLA.

EP2840113 describes a plasticizer that is ester based and contains at least one of the following ethers in a concentra tion not larger than 20 % by weight: bis(2-ethylhexyl)ether, butyl (2-ehtlyhexyl)ether, and dibutyl ether. The plasticisers are molecules of low molecular weight since monoalcohols are used as raw material to yield the ethers.

JPH024611 prepares a plasticizer for PLA by reaction of lac tic acid and 2-10 % by weight of PEG. Although the use of lactic acid promotes miscibility with PLA, polymerisation of lactic acid gives PLA which is brittle and since the plasti cizer consists of at least 90 % by weight of lactic acid, the efficiency of the plasticizer is low.

US2017/0267905 discloses antistatic agents for thermoplastic resins and in example 8 it is disclosed that said antistatic agent can be prepared from a cycloaliphatic dialcohol, cyclo aliphatic dicarboxylic acid, polyethylene glycol and citric acid.

US2013/0108732 discloses a polyester for use in chewing gum. The polyester is created from at least one dicarboxylic acid, at least one diol and at least one compound having at least three groups capable of ester formation. In examples it is disclosed that diethylene glycol can be used as diol.

Summary of the invention

The present invention relates to a group of plasticisers that can be used to modify the mechanical, physical, and chemical properties of resins, in particular polyester resins. The modification particularly relates to increasing elongation at break, fracture toughness, and impact strength. The invention also relates to resins containing said plasticiser. The plas ticisers are preferably degradable in nature and are prefera bly at least partly derived from renewable sources.

As used herein, the term poly (lactic acid), abbreviated PLA, refers to any of the isomeric states of poly (L-lactic acid), poly (D-lactic acid) and poly (L,D-lactic acid) or mixtures hereof. The term mixtures also include both random mixing of any of the isomeric states and scenarios where one or a mix ture is coated with another or mixture of isomeric states.

As used herein, the term monomer refers to a molecule that can undergo polymerisation. A monomer can react with an iden tical or different monomer molecule to yield another molecule that can also be termed a monomer.

For molecules with one or more unsaturated carbon double bonds, the name of the molecules refers to both cis and trans enantiomers and combinations hereof unless otherwise speci fied.

For molecules containing one or more chiral carbon atoms, the name of the molecule refers to both L and D enantiomers and combinations hereof unless otherwise specified.

Multifunctional alcohol is a molecule containing at least two hydroxyl groups and at least one more reactive group such a carboxyl, hydroxyl, amine, anhydride, isocyanate, epoxy and unsaturated carbon bonds. Hence, examples of multifunctional alcohols are triols and glyceric acid.

Multifunctional carboxylic acid is a molecule containing at least two carboxyl groups and at least one more reactive group such a carboxyl, hydroxyl, amine, anhydride, isocya nate, epoxy and unsaturated carbon bonds. Hence, examples of multifunctional carboxylic acids include propane 1,2,3- tricaboxylic acid and malic acid.

As used herein, molar masses are measured by means of gel permeation chromatography (GPC) using polystyrene as stand ard. The choice of eluent in the GPC measurement relies on the chemical composition of the analysed substance as solu bility of the substance in the eluent is required, but tetra- hydrofuran and chloroform (trichloromethane) are preferred eluent choices. Various columns can be used in the GPC meas urement varying in particle type and size. The use of stand ards such as polystyrene for calibrating between retention time and molar mass corrects for any differences in the re tention time introduced by varying the column material and size of the column material. The skilled person knows to se lect a column with a resolving range matching the molar mass of the analysed substance, with large particle size suitable for high molar mass substances and small particle sizes suit able for low molar mass substances. Unless otherwise speci fied, molecular mass refers to number average molecular mass. As known to the person skilled in the art, the terms molar mass and molecular mass are used interchangeably. Similarly, the words mass and weight are used interchangeably.

The invention relates to poly (ester ethers) that is mole cules containing both ester and ether linkages in its chemi cal backbone and the backbone has a length that classifies the molecule as a polymer. In this invention molecules with a number average molecular mass below 1100 g/mol are determined monomers or oligomers and therefore the polymers of the pre sent invention have a molecular mass of at least 1500 g/mol. As the molar mass increases, the molecular mobility of the polymer chain decreases, and thus greater molar masses are advantageous for avoiding migration or bleeding of the plas ticiser. This is advantageous when the plasticiser is blended with other resins for ensuring the stability of the blended resin over time. Further, by increasing the molecular mass of the plasticiser, the volatility of the plasticiser reduces. Preferably, the molar mass is at least 2000 g/mol, more pref erably at least 5000 g/mol, even more preferably at least 8000 g/mol and most preferably at least 10000 g/mol.

Ester linkages are often created through a condensation reac tion between an alcohol and a carboxylic acid group but can also be established in a polymer backbone through ring open ing of a cyclic molecule. In preferred embodiments of the in vention, ester linkages in the polymer backbone are created through reaction of dialcohols and dicarboxylic acids and preferably a multifunctional alcohol or carboxylic acid, i.e., a molecule containing at least 3 alcohol and/or carbox ylic acid groups, in a concentration below 20 % by weight of the plasticiser, preferably below 15 % by weight, more pref erably below 10 % by weight and most preferably below 5 % by weight. Preferably, the dialcohols and dicarboxylic acids are linear unbranched molecules and preferably with the alcohol and carboxylic acid groups positioned at the end of the mole cule (Figure 1). Preferably, the multifunctional alcohol or carboxylic acid is a multifunctional alcohol. The length of the carbon chain between the reactive end groups is important to the mechanical properties of the plasticiser and its mis cibility with polyester resin.

A long carbon segment improves the flexibility of the result ing polymer and thereby its ability to act as a plasticiser, but on the other hand reduces the miscibility with polyester resins, in particular with PLA and poly glycolide. The ratio between carbon and oxygen atoms should not deviate substan tially from that of the resin the plasticiser is blended with when miscibility is required. Therefore, the number of carbon atoms in the dialcohols and dicarboxylic acids is 2-20 (n in Figure 1 equals 0-18), preferably 2-15 and most preferably 3- 10. The plasticiser can consist of a plurality of dialcohols and dicarboxylic acids in order to obtain the desired balance between plasticising effect and miscibility. In case the plasticiser consists of a plurality of dialcohols and dicar boxylic acids, the number of carbon atoms is calculated as a weighted average based on the mass of each dialcohol and di carboxylic acid and the number of carbon atoms in each of them. When the plasticiser consists of a plurality of dialco hols and diacids, the average number of carbon atoms is pref erably 3-8.5, preferably 4.1-8.

D

Figure 1

In various embodiments of the invention both dicarboxylic ac ids and dialcohols are saturated to avoid extensive cross linking and oxidation of the polymer. Advantageous dicarbox ylic acids are malonic acid, succinic acid, adipic acid, su beric acid, azaleic acid, sebacic acid, 2-methylsuccinic acid and ketoglutaric acid. Advantageous alcohols are 1,2-ethane- diol, 1,3-propanediol, 1,2 propanediol, 1,4-butanediol, 1,3- butanediol, 2,3-butanediol, 1,5-heptanediol, 1,6-hexanediol,

1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol.

The multifunctional alcohol or carboxylic acid can be a plu rality of molecules and can in addition to either an alcohol or carboxylic acid group also comprise an anhydride or amine group. Examples of suitable molecules include malic acid, citric acid, tartaric acid, glucose, fructose, sucrose, glyc erol, xylitol, sorbitol, glyceric acid, and suitable amino acids such as arginine, lysine, asparagine, and serine.

In various aspects of the invention, part of the dialcohol is replaced by a diamine or a molecule containing one primary amine group and a carboxylic acid or alcohol group to intro duce amide bonds into the plasticiser. Preferably the dialco hol substitution percentage is below 10 % by weight, more preferably below 7 % by weight and most preferably below 5 % by weight. The replacement of ester with amide linkages in the plasticiser modifies the mechanical properties of the plasticiser and increases the miscibility with resins com prising amide bonds. Preferred molecules for substitution of dialcohol comprise alanine, isoleucinemethionine, phenylala nine, glycine, valine, isophoronediamine, 1,3-propanediamin,

1,4-butanediamiane, 1,5-pentanediamine, 1,6-hexanediamine,

1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, aminomethanol, ethanolamine, propanolamine, aminomethyl pro panol, and valinol.

In various embodiments of the invention, the plurality of monomers used to synthesise the plasticiser is free of mole cules with only a single reactive group such as hydroxyl and carboxylic acid groups since inclusions of these reduce the molecular weight of the plasticiser.

In addition to ester linkages, the plasticiser of the present invention also comprises ether bonds as ether bonds can have advantageous plasticising effects. In the present invention, the ether and ester bonds must be present in the same molecu lar chain rather than in two separate molecular networks. To achieve this, either a molecule with at least one ether moi ety and reactive groups towards alcohol and/or carboxylic ac ids or a molecule capable of forming an ether upon reaction with the dialcohols during the synthesis of the plasticiser is required. An ether group can be formed upon reaction of two alcohol groups or an alcohol and an alkyl halide under alkaline conditions.

In preferred embodiments of the invention, the ether bonds in the polymer backbone of the plasticiser is created by using a molecule containing at least one ether group and at least two chemical groups that can undergo reaction with alcohols or carboxylic acids. Preferably, said at least two chemical groups are alcohol, carboxylic acid, or amine groups. Advan tageously, the amount of molecules containing ether groups is 10-50% by weight, preferably 15-40% by weight, more prefera bly 20-35% by weight and most preferably 21-33 % by weight.

In various embodiments, when the ether moieties of the plas ticiser are created during the synthesis of the plasticiser, the content of the molecules forming the ether groups is 10- 50% by weight, preferably 15-40% by weight, more preferably 20-35% by weight, and most preferably 21-33 % by weight. In preferred embodiments of the invention, the molecule contain ing at least one ether group has a number average molecular weight of at least 140 g/mol, more preferably at least 200 g/mol.

In various embodiments of the invention, the amount of aro matic molecules is below 20 % by weight, more preferably be low 10 % by weight, even more preferably below 5 % by weight, and most preferably the plasticiser of the invention is free of aromatic moieties since these provide stiffness and brit tleness to polymer structures. In other embodiments of the invention, the amount of cycloaliphatic molecules is below 50 % by weight, preferably 20 % by weight, more preferably below 10 % by weight, even more preferably below 5 % by weight, and most preferably below 2 % by weight of cycloaliphatic com pounds. In further embodiments of the invention, the sum of aromatic and cycloaliphatic molecules is below 50 % by, pref erably below 20 % by weight, more preferably below 10 % by weight, even more preferably below 5 % by weight. Both aro matic and cycloaliphatic moieties increase the glass transi tion temperature of the plasticiser, which can reduce the plasticising effect of the plasticiser.

To obtain a polymer with molecular weight that is above the threshold of migration when blended with other resins, the stoichiometry between the reactive groups is important. Pref erably, no reactive groups are present in a molar excess of not more than 10 % relative to the chemical groups it can un dergo reaction with, preferably not more than 5 %, more pref erably not more than 2 %, and most preferably not more than 1 %.

To reduce the carbon footprint of the plasticiser, said plas ticiser is at least partly produced from renewable materials. In order to introduce renewable content to the plasticiser, molecules fully or partly derived from renewable materials can be employed for synthesis of the plasticiser. In advanta geous embodiments of the invention, the plasticiser is pro duced from at least 40 % by weight of renewable materials, preferably at least 60 % by weight, more preferably at least 70 % by weight, even more preferably at least 80 % by weight, and most preferably 100 % by weight of renewable materials.

Renewable materials, as example according to the Rutgers University Center for Sustainable Materials at The State University of New Jersey (USA), are to be understood as ma terials that do not use up non-renewable resources. Renewa ble materials are those which can be manufactured or gener ated quickly enough to keep pace with how fast they are used up. Renewable materials can be made from natural prod ucts or may be synthetically produced, and renewable mate rials may include recycled products.

In advantageous embodiments of the invention, the plasticiser is prepared through bulk polymerisation, which means no sol vents are used. In bulk polymerisation, the raw materials are added to the reaction vessel and during stirring and heating, the raw materials melt and dissolve to form a homogeneous mixture. Through bulk polymerisation, the use of solvents is omitted which contributes to cost effectiveness, reduced health risk, and lower environmental footprint. To increase the reaction rate, a catalyst can be added to the raw materials used in the preparation of the plasticiser. Ac ids with a pK _a value lower than the carboxylic acids used in the preparation of the plasticiser are suitable. Acids with out a carboxylic acid group, especially inorganic acids, are preferred since they will not be incorporated into the poly mer network forming the plasticiser. Other suitable catalysts include zinc acetate, magnesium acetate, calcium acetate, and tin compounds.

The invention also relates to resins comprising the plasti ciser disclosed in this invention. The plasticiser can be mixed into the resin by various approaches such as extrusion. Mixes in which the plasticiser has the concentration of the final compound, that can be used for various purposes such as injection moulding, thermoforming and fibre spinning, can be prepared as well as concentrates of a resin and the plasti ciser that can be used as masterbatches. For final compounds, the concentration of the plasticiser is between 1 and 25 % by weight, preferably 2-20 % by weight, and most preferably 3-15 % by weight. For concentrates, the concentration of the plas ticiser is 25-65 % by weight, preferably 30-60 % by weight, and most preferably 35-60 % by weight. In preferred embodi ments of the invention, at least half of the weight of the resin or resins that the plasticiser is mixed into is PLA.

It is advantageous to have miscibility between the plasti ciser and the resin (s) it is blended with since inclusion of a compatibilising unit in the plasticiser molecule can be omitted. By omitting a compatibilising unit meanwhile having miscibility between the plasticiser and the resin (s) it is blended with, less plasticiser is needed to obtain the de sired effect. To characterise the miscibility, a differential scanning calorimetry measurement can be performed. If the blended resin only contains one glass transition temperature and/or melting point the polymers are miscible. In advanta geous embodiments of the invention, a blend of the plasti ciser of the present invention with PLA in plasticiser con centrations up to 5 % by weight is miscible, preferably in plasticiser concentrations up to 10 % by weight, more prefer ably in plasticiser concentrations up to 15 % by weight, even more preferably in plasticiser concentrations up to 20 % by weight, and most preferably in plasticiser concentrations up to 30 % by weight. In various embodiments of the invention, the same concentrations of miscibility apply to poly gly- colide, poly butylene succinate, and poly hydroxyalkanoates.

In various embodiments of the invention, the plasticiser or resin containing the plasticiser is dyed. The selection of the molecules in the dye composition is based on the desired colour and appearance such as gloss of the dye. Preferably the selected dye is free of petroleum derived content, which can be obtained by using natural dyes, synthetic dyes pre pared from renewable materials, and minerals. Examples of natural dyes include indigo, madder, weld, cutch, safflower, turmeric, barberry roots, and bark, wood from Caelsapina sap- pan, marigold oak gall, lawsone, lapachol, juglone, alkanan, alizarin, morindadiol, soranjidiol, purpurin, laccaic acid, kermesic acid, carminic acid, carbon black chalcone, and bixin. Suitable minerals include but is not limited to tita- nia, iron oxides, iron hydroxides, copper hydroxides, organic copper complexes titania coated mica, zinc ferrite, and lapis lazuli.

Another property important for certain polymer applications is UV stability. For resin compositions where inherent UV stability is below the required level, the UV stability can be increased by adding one or more antioxidants or UV absorb ers to the resin composition. To improve the UV stability hindered amine light stabilisers can be added and suitable molecules include bis(1,2,2,6,6-pentamethyl-4-piperidyl)seba- cate and methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate. In various aspects of the invention, resins containing the plasticiser also comprise fillers that can be both organic and inorganic. Examples of suitable organic fillers are natu ral fibres such as flax, hemp, wood, jute, kenaf, bamboo, and natural seeds from sources such as flax, grape, sunflower, and rape. Inorganic fillers are preferably naturally occur ring minerals and synthetic structures that can enter biolog ical cycles. Examples of such inorganic fillers are silica, calcium sulphate, hydrated forms of calcium sulphate, calcium carbonate, hydroxyapatite, talc, sand, granite, stone, alu minium oxides, aluminium hydroxides, and phosphates.

Resin compositions disclosed in various embodiments can be combined to yield properties that are unattainable by using a only a single group of aspects of the invention. As an exam ple, the plasticiser can be adapted towards an amide resin containing aromatic moieties, by including aromatic molecules in the synthesis of the plasticiser and by substituting part of the dialcohol with a compound containing at least one pri mary amine group and at least one another group reactive to wards at least one of the reactive groups found in the plas ticiser constituents. Another example of combination of em bodiments is a plasticiser containing both aromatic and cy cloaliphatic structures.

Specimen comprising the plasticiser and resins containing the plasticiser of the present invention can be manufactured us ing various processing techniques such as injection moulding, fibre spinning, yarn spinning, blow moulding, extrusion, and thermoforming. The present invention also relates to products manufactured from resins containing the plasticiser of the present invention. Resins containing the plasticiser of the present invention can be used to substitute various petro leum-based polymers such as poly ethylene (PE), poly propyl ene (PP), poly ethylene terephthalate (PET), poly butylene terephthalate (PBT), and acrylonitrile butadiene styrene (ABS).

Polymeric blends containing the plasticiser such as a melt blended resin of PLA can be used to produce various parts by means of injection moulding. Injection moulding is used to produce a plurality of products and as exemplified, melt blended resins comprising the plasticiser of this invention can be used to substitute fossil-based polymers such as PE, PP, PET, PBT, and ABS to create injection moulded products. Said injection moulded products can be applied for various purposes among others, furniture, toys, packaging, buttons and mobile phone covers.

In various aspects of the invention, resins comprising the plasticiser of the present invention are used to produce bags and films. Bags and films are commonly produced by means of blowing or casting using PE and PP as raw material. Particu larly advantageous resins for creation of bags and films com prise PLA and the plasticiser of the present invention.

In various embodiments of the invention, blends comprising the plasticiser of the invention and other polymers such as PLA, poly glycolide, and poly hydroxyalkanoates are used to spin fibres or yarns for preparation of textiles in both wo ven and knitted form. Fibres are normally spun into a yarn that is later woven or knitted into a fabric whereas multi filament yarns can be directly prepared into a fabric by means of weaving or knitting. The textiles are particularly advantageous for apparel, shoes, clothing and other applica tions involving contact with human skin.

In a plurality of aspects of the invention, polymer blends comprising the plasticiser of the invention is used for prep aration of both mono-component and bi-component staple fi bres. A bi-component fibre is a fibre with a core of a high melting point coated with a sheath that is constituted by an other polymer type that has a lower melting point than the core. Resins, particularly PLA, comprising the plasticiser of the invention can be used as both sheath and core layer of bi-component fibres. Staple fibres are used for preparing non-woven fabrics that are applicable for various products such as diapers, feminine hygiene pads, cigarette filters, tissues, facial masks, wet wipes, shopping bags and polishing and cleaning cloths.

In various embodiments of the invention, the plasticiser of the present invention, is used as an initiator for ring open ing polymerisation of a cyclic monomer onto the plasticiser. Due to the monomers used in the preparation of the plasti ciser, it comprises hydroxyl and carboxyl ending groups. Such groups can initiate ring opening of cyclic monomers with a certain polarity such as lactones, lactames, lactide and gly- colide. Upon ring opening, the molecular chain of the monomer grows from the initiating group creating a block polymer with the plasticiser forming the core of the block polymer.

The present invention will be described with examples. While the examples illustrate the invention, it is not limited thereto .

Example 1:

A round bottomed flask equipped with a stirrer, a reflux con denser, and a pressure gauge is placed in an oil bath at 150 °C. 0.2 mol succinic acid, 0.12 mol butanediol, 0.02 mol cit ric acid, 0.1 mol PEG-200, and 0.03 mol hydrochloric acid are allowed to react for 3h under conditions of reduced pressure below 5000 Pa.

Example 2:

A round bottomed flask equipped with a stirrer is placed in an oil bath at 140 °C and 0.12 mol malonic acid, 0.12 mol glutaric acid, 0.2 mol butanediol, 0.15 mol 1,3-propanediol, 0.02 mol malic acid, 0.1 mol 0,0'-oxydiethylene-diglycolic acid, and 0.03 mol sulphuric acid are allowed to react for 4h under conditions of reduced pressure below 15.000 Pa.

Example 3:

A round bottomed flask equipped with a stirrer, a reflux con denser, and a pressure gauge is placed in an oil bath at 130 °C. 0.2 mol adipic acid, 0.1 mol ethanediol, 0.15 mol lysine, 0.1 mol citric acid, 0.1 mol 0,0'-oxydiethylene-diglycolic acid, 0.05 mol Jeffamine D-230 (polyoxypropylene diamine) and 0.03 mol phosphoric acid are allowed to react for 3h under conditions of reduced pressure below 10.000 Pa.

Example 4:

10 g of the plasticiser of example 1 is in an extruder mixed with 40 g of PLA and extruded into pellets.

Example 5:

A round bottomed flask is placed in an oil bath at 170 °C and 10 g of the plasticiser of example 3, 90 g lactide and 0.1 mg stannous octoate are added to the flask. The mixture is al lowed to react for 2h.

Example 6:

A round bottomed flask equipped with a magnetic stirrer is placed in a silicone oil bath at 170 °C and 15.6 g (0.1 mol)

2,5-furandicarboxylic acid, 5.9 g (0.05 mol) succinic acid and 11.4 g (0.15 mol) 1,3-propanediol are added. When the chemicals have melted, 50 mg 8 mol/L sulphuric acid is added. The mixture is allowed to react for 3 h under atmospheric pressure. Subsequently, 30 g of the plasticizer of example 3 is added to the flask and the pressure is reduced to a value not higher than 10.000 Pa.