WO2011067125A1

WO2011067125A1 - Mouth protector

Info

Publication number: WO2011067125A1
Application number: PCT/EP2010/067866
Authority: WO
Inventors: Thorsten Pretsch
Original assignee: Bundesanstalt für Materialforschung und -Prüfung (BAM)
Priority date: 2009-12-04
Filing date: 2010-11-19
Publication date: 2011-06-09
Also published as: DE102009057080A1

Abstract

The invention relates to a mouth protector that is substantially u-shaped and comprises a shape memory polymer.

Description

mouthguard

The present invention relates to a mouthguard, in particular a sports mouthguard.

A mouthguard is a device for protecting the teeth, lips, tongue and jaw in injuries and accidents sports. Typically, the mouthguard is made of a plastic and has the shape of a substantially U-shaped rail. Mouth guards are used for example in martial arts such as boxing or wrestling, but also in many ball sports such as rugby, football, American football, Australian football, football, lacrosse, handball, basketball or hockey as well as the

Used skiing, snowboarding and skating. In such sports, the risk of tooth and jaw rupture is significantly increased. For example, every third child suffers from sports

Injury to teeth, in three of four cases then the cosmetically striking upper central incisors are affected. Damaged teeth often lead to lifelong follow-up costs, which are usually well above the cost of a sports mouthguard. In addition, mouthguards prevent jaw and cushioning through cushioning and power distribution

TMJ fractures. Furthermore, concussions with mouthguards occur up to sixteen times less often than without the mouthguard.

To provide the benefits described above, a mouthguard should be resilient to cushion shock while rigid enough to dissipate energy and distribute it over as much area as possible. The damping behavior of a mouthguard is related to the material thickness, but the force distribution is typically determined by the hardness and elasticity of the material. In addition, the mouthguard should allow unobstructed breathing and neither tension nor push, so have an acceptable wearing comfort. With regard to these requirements, various

Categories of mouthguards are distinguished.

On the one hand, ready-made mouth guards are available in well-stocked sports shops. This is typically a prefabricated makeshift made of soft rubber or plastic. The appropriate hold in the mouth is made by biting it with your teeth to clamp the mouthguard so between the jaws. Although this type of mouthguard is priced favorable, it offers only unsatisfactory protection and is significantly inferior to the other types of mouthguards. More suitable as ready-made mouth guards are individually adjustable mouth guards according to the so-called boil-and-bite principle. This is an individually adjustable mouth guard based on a prefabricated, typified substantially U-shaped plastic rail. This rail is made of ethylene-vinyl acetate and is plastically malleable by heat. The melting temperature of the ethylene-vinyl acetate is T _m ~ 70 ° C. To adjust the mouthguard to the user's jaw, the rail is heated to a temperature above the melting temperature. This can be done for example by heating the rail in water (Boil). The user then bites the now soft plastic splint to create a dental impression in the splint.

Then let the rail to a temperature below the

Cooling crystallization temperature of the ethylene-vinyl acetate, so that the material solidifies in the adapted form. The crystallization temperature is T _c ~ 45 ° C. After cooling, the plastic rail solidifies. The quality of the protection depends strongly on the prevailing conditions of the jaw (average jaw or malformation jaw) and the skill of the adaptor. In addition, the thermoplastic polymer material ethylene-vinyl acetate does not stretch properly and embrittle easily. Due to the embrittlement, the lifetime of mouthguards made of ethylene-vinyl acetate is relatively small. In terms of price, this type of mouthguard is well above the simple mouthguard of the type described above.

The third and highest quality category includes the mouthguards individually made in a dental practice. For this purpose, impressions of the jaw are typically taken and the appropriate surgical mask is made individually outside the mouth in a dental laboratory. This mask is characterized by a very high wearing comfort and an exact adaptation to the rows of teeth and the jaw situation of the wearer. However, this solution is correspondingly expensive, so that it is typically not selected by amateur athletes, for example.

In view of the above, the present invention proposes a mouthguard according to claim 1. Other aspects, advantages and details of the present invention will become apparent from the dependent claims, the description and the accompanying drawings. According to one embodiment, a mouthguard has a substantially U-shaped form. The mouthguard comprises a shape memory polymer. For example, the shape memory polymer may be a poly (ester urethane), a chemically crosslinked semicrystalline trans polyoctenamer, an ethylene oxide ethylene terephthalate copolymer, a poly (ether urethane), polynorbornene, a norbornyl POSS hybrid copolymer, a copolymer of polyethylene terephthalate). and polyethylene glycol), a polymer of the monomer tert-butyl acrylate and the crosslinker diethylene glycol diacrylate, a copolymer composed of the monomers methyl methacrylate and butyl methacrylate and crosslinked by tetraethylene glycol dimethacrylate, a copolymer composed of methyl methacrylate and polyethylene glycol) dimethacrylate is a chemically crosslinked compound based on the monomers methacrylic acid, methyl methacrylate and polyethylene glycol), a copolymer of polyethylene or isotactic polypropylene and a cyclodiolefin, in particular vinylcyclohexene, cyclopentadiene, 1,5-cyclooctadienes, 2,5-norbornadiene, 5-vinyl -2-norbornene, dicyclopentadiene or 5-ethylidene-2-norbornene or a cross-linked poly (vinyl chloride). In particular, the mouthguard based on poly (ester urethane) may be formed.

According to one embodiment, the shape memory polymer may be a shape memory thermoplastic polymer, in particular from the group of linear block copolymers, in particular polyurethanes and polyurethanes with ionic or mesogenic components, block copolymers of polyethylene terephthalate and polyethylene oxide, block copolymers of polystyrene and poly (1,4-butadiene), ABA triblock copolymers poly (2-methyl-2-oxazoline) (A-block) and polytetrahydrofuran (B-block), multiblock copolymers

Polyurethanes with poly (8-caprolactone) switching segment, block copolymers from

Polyethylene terephthalate and polyethylene oxide, block copolymers of polystyrene and poly (l, 4-butadiene), polyurethane systems, the hard segment-forming phase of

Methylendiphenyldiisocyanat (MDI) or toluene-2,4-diisocyanate and a diol, in particular 1,4-butanediol, or a diamine and a switching segment based on an oligoether, in particular polytetrahydrofuran or an oligoester, in particular

Polyethylenadipat, Polypropylenadipat, Polybutylenadipat, Polypentylenadipat or

Polyhexalenadipat consists materials with a hard segment-forming phase of toluene-2,4-diisocyanate, MDI, diisocyanates, in particular of MDI or

Hexamethylene diisocyanate in carbodiimide-modified form and from chain extenders, in particular ethylene glycol, bis (2-hydroxyethyl) hydroquinone or a combination of 2,2-bis (4-hydroxyphenyl) propane and ethylene oxide are constructed whose Schaltsegment- determining blocks of oligoethers, especially polyethylene oxide, polypropylene oxide, polytetrahydrofuran or from a combination of 2,2-bis (4-hydroxyphenyl) propane and propylene oxide, or oligoesters, in particular polybutylene adipate, materials of polynorbornene, graft copolymers of polyethylene / nylon-6, block copolymers with polyhedral oligomeric silsesquioxanes (POSS), including the combinations polyurethane / POSS, epoxide / POSS, polysiloxane / POSS, polymethylmethacrylate / POSS, silicone-based FGPs and poly (cyclooctene) materials.

In poly (ester urethanes) switching segment blocks u.a. from poly (s-caprolactone) diols with number average molecular weights between 1600 and 8000 build up. The

Switching temperature for the shape memory effect can, depending on the weight fraction of the

Switching segments (variation between 50 and 90% by weight) and molecular weight of poly (8-caprolactone) diols vary between 44 and 55 ° C. The crystallization temperatures are between 25 and 30 ° C.

According to another embodiment, the shape memory polymer may be an elastomeric shape memory polymer, in particular from the group consisting of polyvinyl chloride, polyethylene-polyvinyl acetate copolymers, covalently crosslinked copolymer systems of stearyl acrylate and esters of methacrylic acid, trans-polyisoprene / polyurethane-based, segregated FGP, poly (ether esters) such as Polyethylene oxide) / poly (ethylene terephthalate) copolymers,

Norbornyl / POSS copolymers, poly (methylene-1,3-cyclopentane) and its copolymer with polyethylene, styrene / butadiene copolymers, thiol-ene / acrylate copolymers, polynorbornene, polymer networks made of poly (8-caprolactone) (PCL) and dimethacrylates, Poly (8-caprolactone) (PCL) -based FGPs, acrylate-based FGPs, (meth) acrylate networks, cross-linked polyethylene, epoxide-based FGPs, a polyurethane / phenoxy blend, or a polyurethan / polyvinylchloride (PVC) blend.

According to another embodiment polyadipate-based poly (ester urethanes) are considered for the application outlined, because their switching temperature of the soft segments near body temperature (about 37 ° C) and the crystallization temperature is slightly below room temperature (<10 ° C) , In addition, the material has sufficient shape memory properties (mold recoverability, fixability) and long-term stability. For the described poly (ester urethane) could be a slight Processability can be demonstrated. Complete dissolution in common solvents such as tetrahydrofuran and subsequent evaporation of the solvent in a specially prepared template is possible. It was shown that in 5 ml of tetrahydrofuran 250 mg of poly (ester urethane) dissolve and that the films obtained after evaporation of the solvent have almost unchanged shape memory properties. Alternatively, the FGP can be directly melted in a vacuum oven and then poured into a stencil

(Experimental conditions: 220 ° C and 20 mbar). Samples obtained in this way also have almost unchanged shape memory properties compared to the starting material.

If the mouthguard is made of a shape memory polymer, in particular of poly (ester urethane), the material can be repeatedly deformed even after a relatively long time and only becomes brittle at a very late point in time. Furthermore, at

Shape memory polymers, e.g. Poly (ester urethanes), numerous parameters about the

Synthesis are set. This applies in particular to the crystallinity of the soft segments and the associated mechanical parameters, in particular the material hardness and the extensibility, as well as the thermo-mechanical properties, in particular the

Elongation fixability, stretch recoverability and transformation temperature above which the material deforms. With the shape memory polymer technology, therefore, both safe and comfort-enhancing mouth guards can be produced. For example, a mouthguard made of poly (ester urethane) is stretchable by several hundred percent, and its ease of deformability above the transformation temperature makes good matching possible. The mouthguard can also be used repeatedly at a later time. In particular, the mouthguard could also be used by other wearers after previous cleaning. The long-term stability of

Shape memory polymers, such as poly (urethane urethanes), is significantly improved over the conventional ethylene-vinyl acetate. For example, in addition to excellent mechanical properties for poly (ester urethanes), the memory of form memory and thus the self-healing effect can be retrieved even over very long periods of time without age-related material damage. In addition, mouthguards based on poly (ester urethane) are more cost-effective than conventional mouthguards made from ethylene-vinyl acetate. In a further development, the shape memory polymer further contains a stabilizer. For example, the poly (ester urethane) stabilizer may comprise a carbodiimide.

In one embodiment, the shape memory polymer has between 0.01% and 3% by weight, based on the ester portion, of stabilizer.

Stabilized shape memory polymers, e.g. Poly (ester urethanes), are not biodegradable, so that a mouthguard is not degraded by its use. Even after significant material stress, the stabilized poly (ester urethane) has excellent mechanical and thermo-mechanical properties. Stabilized poly (ester urethane) is long-term stable and inexpensive to produce.

According to a further embodiment, the shape memory polymer,

For example, poly (ester urethane), between 50 parts by weight and 90 parts by weight of switching segments. For example, the shape memory polymer may comprise switching segment blocks of a poly (e-caprolactone) diol. According to a development, the poly (e-caprolactone) diol has an average molecular weight between 1500 and 8500.

In this way, the switching temperature for the shape memory effect depending on

Weight fraction of the switching segment and molecular weight of the poly (8-caprolactone) diols can be varied. The crystallization temperature can also be adjusted in this way. In addition, the hardness at room temperature can be increased by increasing

Soft segment length and growing soft segment content can be increased. This is due to an increased soft-segment crystallinity. At elevated temperature, the hardness decreases with increasing soft segment content and increases with increasing soft segment length. Furthermore, as the soft segment content increases, the tensile strength decreases and the elongation at break increases. The tensile strength can be adjusted with soft segments of poly (8-caprolactone) diols in approximately between 30 and 60 MPa, resulting in elongation at break s between 800 and 1150%.

In yet another embodiment, the shape memory polymer has between 10% and 55% by weight of hard segments.

Although the shape fixability decreases with increasing hard segment content, a small proportion of hard segment leads to poor extensibility. Below a lower one With a limit of about 10% hard segment content, the hard segment domains are typically no longer sufficiently strong and no longer perform their function as physical crosslinkers.

According to yet another embodiment, the switching temperature of the

Shape memory polymer between 40 ° C and 60 ° C and the crystallization temperature of the shape memory polymer between 25 ° C and 30 ° C.

Further advantageous embodiments, details, aspects and features of the present invention will become apparent from the dependent claims, the description and the accompanying drawings. It shows

Fig. 1 is a mouthguard according to an embodiment of the present invention

Invention.

Fig. 2 is a 3-D result of a cyclic thermo-mechanical measurement of a pull rod made of poly (ester urethane).

FIGS. 3 and 4, the results of an aging study (water storage at 80 ° C) of poly (ester urethane) with and without stabilizer.

Fig. 1 shows a mouthguard 100 according to an embodiment of the present invention. The mouthguard 100 is formed substantially U-shaped. In this case, the mouthguard has a thickness D and a width B. The width B and the thickness D are typically chosen so that the mouthguard 100 during use has a labial (lip-side) thickness of 2 to 5 mm, in particular 3 mm, a palatal (palate-sided) thickness of 1 to 3 mm, in particular 2 mm , and an occlusal (Kauflächenbezogene) thickness of 2 to 5 mm, in particular 3 mm.

The mouthguard 100 includes a shape memory polymer (FGP). According to a development, the surgical mask can be made entirely of the shape memory polymer. As shape memory polymers, plastics are generally referred to which, after a transformation, apparently "remember" their former external form and thus have a shape memory Exceeding a so-called switching temperature triggered. Among these thermosensitive FGPs, one can generally distinguish between FGPs for which the switching temperature corresponds to a glass transition (Ttra _ns = T _g ) and FGPen for which the switching temperature corresponds to the melting temperature of crystalline soft segments (Ttrans = T _m ). In the latter case, the FGPs have two components, wherein a first component is an elastic polymer (hard segment) and the second component is a hardening wax (soft segment). If the FGP is deformed, the elastic polymer is "arrested" by the hardened wax in its deformed form, and if the FGP is subsequently heated, the wax softens and can no longer counteract a restoring spring force of the elastic component Many known FGPs have a thermally induced shape memory effect, which means that upon polymerisation of programmed polymeric materials over a defined transition temperature, an entropy elasticity driven recovery takes place.

Shape memory polymers are usually polymer networks in which chemical

(Covalent) or physical (non-covalent) crosslinking sites determine the permanent shape. Phase segregated, linear block copolymers are made of hard and

Soft segments built.

For example, the following shape memory polymers can be used to make the mouthguard: a poly (ester urethane), a chemically crosslinked semicrystalline trans polyoctenamer, an ethylene oxide ethylene terephthalate copolymer, a poly (ether urethane), polynorbornene, a norbornyl POSS hybrid Copolymer, a copolymer of polyethylene terephthalate) and polyethylene glycol), a polymer of the monomer tert-butyl acrylate and the cross-linker diethylene glycol diacrylate, a copolymer composed of the monomers methyl methacrylate and butyl methacrylate and cross-linked by tetraethylene glycol dimethacrylate, a copolymer, which is composed of methyl methacrylate and polyethylene glycol) dimethacrylate, a chemically crosslinked compound based on the monomers methacrylic acid, methyl methacrylate and polyethylene glycol), a copolymer of polyethylene or isotactic polypropylene and a cyclodiolefin, in particular vinylcyclohexene, cyclopentadiene, 1,5-Cyc loctadienes, 2,5-norbornadiene, 5-vinyl-2-norbornene, dicyclopentadiene or 5-ethylidene-2-norbornene, a cross-linked poly (vinyl chloride). According to one embodiment, the shape memory polymer may be a shape memory thermoplastic polymer, in particular from the group of linear block copolymers, in particular polyurethanes and polyurethanes with ionic or mesogenic components, block copolymers of polyethylene terephthalate and polyethylene oxide, block copolymers of polystyrene and poly (1,4-butadiene), ABA triblock copolymers poly (2-methyl-2-oxazoline) (A-block) and polytetrahydrofuran (B-block), multiblock copolymers

Polyethylenadipat, Polypropylenadipat, Polybutylenadipat, Polypentylenadipat or

Hexamethylene diisocyanate in carbodiimide-modified form and from chain extenders, in particular ethylene glycol, bis (2-hydroxyethyl) hydroquinone or a combination of 2,2-bis (4-hydroxyphenyl) propane and ethylene oxide are constructed whose Schaltsegment- determining blocks of oligoethers, especially polyethylene oxide , Polypropylene oxide, polytetrahydrofuran or a combination of 2,2-bis (4-hydroxyphenyl) propane and propylene oxide, or of oligoesters, especially polybutylene adipate, materials of polynorbornene, graft copolymers of polyethylene / nylon-6, block copolymers with polyhedral oligomers Silsesquioxanes (POSS), including the combinations polyurethane / POSS, epoxide / POSS, polysiloxane / POSS, polymethyl methacrylate / POSS, silicone-based FGPs, and poly (cyclooctene) materials.

In poly (ester urethanes) switching segment blocks u.a. from poly (8-caprolactone) diols with number average molecular weights between 1600 and 8000 build up. The

Switching segments (variation between 50 and 90% by weight) and molecular weight of poly (8-caprolactone) diols vary between 44 and 55 ° C. The crystallization temperatures are between 25 and 30 ° C. According to another embodiment, the shape memory polymer may be an elastomeric shape memory polymer, in particular from the group consisting of polyvinyl chloride, polyethylene-polyvinyl acetate copolymers, covalently crosslinked copolymer systems of stearyl acrylate and esters of methacrylic acid, trans-polyisoprene / polyurethane-based, segregated FGP, poly (ether esters) such as Polyethylene oxide) / poly (ethylene terephthalate) copolymers,

According to another embodiment polyadipate-based poly (ester urethanes) are considered for the application outlined, because their switching temperature of the soft segments near body temperature (about 37 ° C) and the crystallization temperature is slightly below room temperature (<10 ° C) , In addition, the material has sufficient shape memory properties (mold recoverability, fixability) and long-term stability. For the described poly (ester urethane) could be a slight

Processability can be demonstrated. Complete dissolution in common solvents such as tetrahydrofuran and subsequent evaporation of the solvent in a specially prepared template is possible. It was shown that in 5 ml of tetrahydrofuran 250 mg of poly (ester urethane) dissolve and that the films obtained after evaporation of the solvent have almost unchanged shape memory properties. Alternatively, the FGP can be directly melted in a vacuum oven and then poured into a stencil

In the following, reference will now be made, by way of example, to a poly (ester urethane) based shape memory polymer. However, this is not meant to be limiting since the other shape memory polymers listed are also suitable for use in a mouthguard. The poly (ester urethane) can be made for the preparation of the mouthguard, for example by an injection molding process in the permanent U-shape form. By later heating on the material-specific switching temperature, the material is deformable and can then be adjusted. The adjustment is made by the wearer taking the heated mouthguard in the mouth and biting on it. The subsequent fixation of the form takes place by cooling the mask under the material-specific fixing temperature. The mask can be easily adapted to the jaw of the wearer. By repeated heating on the switching temperature, the initial state of the mouthguard can be restored.

To illustrate the shape memory effect, a 3-D result log of a cyclic thermo-mechanical measurement of a tensile bar made of poly (ester urethane) in a stress-strain-temperature diagram is shown in FIG. This clearly shows how the staff always follows the same trajectory in the state space, i. how the rod returns from a deformed shape to its original shape again and again.

Furthermore, the poly (ester urethane) shape memory polymer can be used both with and without a stabilizer. In one embodiment, the stabilizer may be a carbodiimide. Typically, the shape memory polymer has a stabilizer content between 0.01% by weight and 3% by weight, based on the ester fraction. A comparison of the mechanical characteristics for non-stabilized and stabilized poly (ester urethane) shape memory polymer and for ethylene vinyl acetate is given in Table I.

Table I From this it can be seen that the tested poly (ester urethane) compared to ethylene vinyl acetate has a similar high elongation at break, a higher tensile strength and a higher Young's modulus.

Furthermore, a comparison of the thermo-mechanical characteristics of non-stabilized and stabilized poly (ester urethane) shape memory polymer was performed. A total of N = 5 thermo-mechanical cycles were run through. The results are shown in Table II.

Table II

As a result, the non-stabilized poly (ester urethane) shape memory polymer and the stabilized poly (ester urethane) shape memory polymer have substantially similar thermo-mechanical properties.

However, it is found that the non-stabilized poly (ester urethane) shape memory polymer and the stabilized poly (ester urethane) shape memory polymer have distinctly different aging behaviors. In the Fign. 3 and 4 are the results of an aging study

(Water storage at 80 ° C) of poly (ester urethane) with and without stabilizer shown. In both Figures 3 and 4, the solid symbols indicate the FGP without stabilizer and the unfilled symbols the FGP with stabilizer.

As a result of the aging study, it was found that the stabilizer-containing material has about a factor of 6.5 higher resistance to embrittlement than that non-stabilized material. The embrittlement of samples of the non-stabilized material had progressed so far after 8 days that the samples in the form of tensile bars could no longer be tested on the following day. On the other hand, this condition only occurred after 52 days for the stabilized material. It was also found that the material lost significant mass only long after it had embrittled, with the unstabilized FGP occurring after about 15 days and the stabilized FGP after more than 100 days. In addition, it has been shown that the shape memory and thus the "self-healing" effect of the poly (urethane urethane) can be retrieved over very long periods of time, without aging-related material damage, such as embrittlement, being noticeably noticeable.This is shown by way of example in FIG it due to the plasticizer effect of water to a deterioration of the mechanical

Properties of a poly (ester urethane). For the stabilizer-protected material, however, there is a significant delay in the onset of significant parameter changes, which is approximately 40 to 44 days. The modified mechanical and thermo-mechanical properties attributable to the plasticizer effect are known for the

Use of the material as a mouthguard, however, is still sufficient.

In another embodiment, the shape memory polymer has between 50% and 90% by weight of switching segments. For example, that can

Shape memory polymer comprise switching segment blocks of a poly (e-caprolactone) diol. According to a development, the poly (e-caprolactone) diol has an average molecular weight between 1500 and 8500.

In this way, the switching temperature for the shape memory effect depending on

Soft segment length and growing soft segment content can be increased. This is due to an increased soft-segment crystallinity. At elevated temperature, the hardness decreases with increasing soft segment content and increases with increasing soft segment length. Furthermore, as the soft segment content increases, the tensile strength decreases and the elongation at break increases. The tensile strength can be adjusted with soft segments of poly (8-caprolactone) diols in approximately between 30 and 60 MPa, resulting in elongation at break s between 800 and 1150%. Decisive for the right selection of materials are the strength and rigidity of the FGP, as well as its deformability and fixability. For poly (ester urethanes) many of these mechanical parameters can be adjusted via synthesis. This relates to the crystallinity of the soft segments and the associated mechanical parameters, in particular the material hardness and the extensibility, as well as the thermo-mechanical properties, in particular the Dehungsfixierbarkeit, the

Stretch recoverability and the transformation temperature, above which the material can be deformed.

Although the shape fixability decreases with increasing hard segment content, a small proportion of hard segment leads to poor extensibility. Below a lower limit of about 10 weight percent hard segment, the hard segment domains are typically no longer sufficiently strong and no longer perform their function as physical crosslinkers.

According to yet another embodiment, the switching temperature of the

Shape memory polymer between 40 ° C and 60 ° C and the crystallization temperature of the shape memory polymer between 25 ° C and 30 ° C. This is especially the

Switching temperature of the shape memory polymer in a range that makes the heated blank appear in the mouth as pleasant and not too hot.

In another embodiment, the shape memory polymer is a chemically cross-linked semi-crystalline trans polyoctenamer. In this FGP Ttr _ans = T _m can be adjusted by the addition of dicumyl peroxide. Typical values are Ttrans = T _m = 58 ° C and Τ ^ = T _c = 24 ° C.

In another embodiment, the shape memory polymer is a poly (ester urethane) prepared from 4,4'-diphenylmethane diisocyanate (MDI), poly (butylene adipate) glycol (PBAG) and trimethylol propane (TMP). For this, values of Ttrans> 40 ° C can be set. In another embodiment, the shape memory polymer is a cross-linked poly (ester urethane) composed of polycaprolactone diol (PCL), 1,4-butanediol (BD), dimethylol propionic acid (DMPA), triethylamine, and 4,4'-diphenylmethane diisocyanate (MDI). to which an excess of MDI or glycerin is added formed. Values of

= T _{m can be set} in the range of 47 ° C to 56 ° C.

In another embodiment, the shape memory polymer is an ethylene oxide-ethylene terephthalate copolymer. The switching temperatures can be adjusted via the synthesis between = T _m in the range of 52 ° C to 62 ° C and = T _c in the range of 20 ° C to 31 ° C.

In another embodiment, the shape memory polymer is a poly (ether urethane), for example, composed of 4,4'-diphenylmethane diisocyanate (MDI), 1,4-butanediol (BD), and poly (tetramethyl oxide) glycol (PTMO). The switching temperature Ttra _ns = T _g is about 54 ° C.

In another embodiment, the shape memory polymer is a

Polynorbornen with a switching temperature Ttrans = T _g = 40 ° C.

In another embodiment, the shape memory polymer is a norbornyl-POSS hybrid copolymer having a switching temperature

= T _g in the range of 47 ° C to 73 ° C.

In another embodiment, the shape memory polymer is a copolymer of polyethylene terephthalate (PET) and polyethylene glycol (PEG), wherein the

switching temperature

= T _g > 34 ° C.

According to another embodiment, the shape memory polymer is a polymer consisting of the monomer tert-butyl acrylate (tBa) and the cross-linker diethylene glycol diacrylate (DEGDA), wherein the shape memory polymer typically has a switching temperature of approximately = T _g = 65 ° C.

In another embodiment, the shape memory polymer is a copolymer composed of the monomers methyl methacrylate (MMA) and butyl methacrylate (BMA) and cross-linked by tetraethylene glycol dimethacrylate (TEGDMA). The hangs Switching temperature (Ttr _ans = T _g ) from the monomer ratio and can typically be set between 27 ° C and 66 ° C.

In another embodiment, the shape memory polymer is a copolymer composed of methyl methacrylate (MMA) and polyethylene glycol dimethacrylate (PEGDMA). The switching temperature Ttrans = T _{g can} typically be set between 56 ° C and 92 ° C.

In another embodiment, the shape memory polymer is a chemically crosslinked compound made from the monomers methacrylic acid (MAA), methyl methacrylate (MMA) and polyethylene glycol (PEG). Here, for example, the

Switching temperature in the range of

= T _g = 75 ° C.

In another embodiment, the shape memory polymer is a copolymer of polyethylene or isotactic polypropylene and cyclodiolefins such as vinylcyclohexene, cyclopentadiene, 1,5-cyclooctadiene, 2,5-norbornadiene, 5-vinyl-2-norbornene (VNB), dicyclopentadiene (DCPD) or 5 -Ethylidene-2-norbornene (ENB), for which the switching temperature trans = T _{g can be set} in a wide temperature range.

In another embodiment, the shape memory polymer is a

cross-linked poly (vinyl chloride) (PVC), although the switching temperature can be in the range of Ttrans = T _g = 83 ° C.

The present invention has been explained with reference to exemplary embodiments. These embodiments should by no means be understood as limiting the present invention. In particular, individual characteristics of the various

Embodiments are adopted in other embodiments or different embodiments are combined with each other, as long as the combined

Do not mutually exclude features for technical reasons.

Claims

A surgical mask having a substantially U-shaped form, the surgical mask comprising a shape memory polymer.

The surgical mask of claim 1, wherein the shape memory polymer is selected from the group consisting of: a poly (ester urethane), a chemically crosslinked semicrystalline trans polyoctenamer, an ethylene oxide ethylene terephthalate copolymer, a poly (ether urethane), polynorbornene Norbornyl-POSS hybrid copolymer, a copolymer of polyethylene terephthalate) and polyethylene glycol), a polymer of the monomer tert-butyl acrylate and the cross-linker diethylene glycol diacrylate, a copolymer composed of the monomers methyl methacrylate and butyl methacrylate and cross-linked by tetraethylene glycol dimethacrylate is a

Copolymer which is composed of methyl methacrylate and polyethylene glycol) dimethacrylate, a chemically crosslinked compound based on the monomers methacrylic acid, methyl methacrylate and polyethylene glycol), a copolymer of polyethylene or isotactic polypropylene and a cyclodiolefin, in particular vinylcyclohexene, cyclopentadiene, 1,5- Cyclooctadienes, 2,5-norbornadiene, 5-vinyl-2-norbornene, dicyclopentadiene or 5-ethylidene-2-norbornene, a cross-linked poly (vinyl chloride).

3. Mouthguard according to claim 1 or 2, wherein the shape memory polymer further comprises a stabilizer.

4. Mouthguard according to claim 3, wherein the shape memory polymer is a poly (ester urethane) and the stabilizer is a carbodiimide in a proportion of between 0.01 wt .-% and 3 wt .-, based on the ester content.

5. Mouthguard according to one of the preceding claims, wherein the

Shape memory polymer between 50 wt. And 90 wt. To switching segments has.

6. Mouthguard according to one of the preceding claims, wherein the

Shape memory polymer comprises switching segment blocks of a poly (e-caprolactone) diol.

The surgical mask of claim 6, wherein the poly (e-caprolactone) diol is a median

Having molecular weight between 1500 and 8500.

8. Mouthguard according to one of the preceding claims, wherein the

Shape memory polymer between 10 wt .- and 55 wt .- has hard segments.

9. Mouthguard according to one of the preceding claims, wherein the switching temperature of the shape memory polymer between 40 ° C and 60 ° C and the

Crystallization temperature of the shape memory polymer between 25 ° C and 30 ° C.

10. Use of a poly (ester urethane) based shape memory polymer for

Production of a mouthguard.

11. Mouthguard according to one of claims 1 to 9, wherein the shape memory polymer is a thermoplastic shape memory polymer from the group of linear block copolymers, in particular polyurethanes and polyurethanes with ionic or mesogenic

Components, block copolymers of polyethylene terephthalate and polyethylene oxide, block copolymers of polystyrene and poly (1,4-butadiene), ABA triblock copolymers of poly (2-methyl-2-oxazoline) (A block) and polytetrahydrofuran (B block), Multiblock copolymers of poly (8-caprolactone) -locked polyurethanes, block copolymers of polyethylene terephthalate and polyethylene oxide, block copolymers of polystyrene and poly (1,4-butadiene), polyurethane systems whose hard segment-forming phase is methylene diphenyl diisocyanate (MDI) or toluene-2,4-diisocyanate and a diol, especially 1,4-butanediol, or a diamine and a

Switching segment based on an oligoether, in particular polytetrahydrofuran or an oligoester, in particular polyethylene adipate, polypropylene adipate,

Polybutylene adipate, polypentylene adipate or polyhexal adipate, materials having a hard segment-forming phase of toluene-2,4-diisocyanate, MDI, Diisocyanates, in particular of MDI or hexamethylene diisocyanate in

Carbodiimide-modified form and from chain extenders, in particular

Ethylene glycol, bis (2-hydroxyethyl) hydroquinone or a combination of 2,2-bis (4-hydroxyphenyl) propane and ethylene oxide, whose switching segment-determining blocks of oligoethers, in particular polyethylene oxide,

Polypropylene oxide, polytetrahydrofuran or from a combination of 2,2-bis (4-hydroxyphenyl) propane and propylene oxide, or oligoesters, in particular

Polybutylene adipate, materials of polynorbornene, graft copolymers of polyethylene / nylon-6, block copolymers with polyhedral oligomers

Silsesquioxanes (POSS), including the combinations polyurethane / POS S, epoxide / POSS, polysiloxane / POSS, polymethyl methacrylate / POSS, silicone-based FGPs, and poly (cyclooctene) materials.

12. Mouthguard according to one of claims 1 to 9, wherein the shape memory polymer is an elastomeric shape memory polymer, in particular from the group polyvinyl chloride, polyethylene-polyvinyl acetate copolymers, covalently crosslinked copolymer systems of stearyl acrylate and esters of methacrylic acid, trans-polyisoprene / polyurethane-based, segregated FGP , Poly (ether esters) such as polyethylene oxide) / poly (ethylene terephthalate) copolymers, norbornyl / POSS copolymers, poly (methylene-l, 3-cyclopentane) and its copolymer with polyethylene, styrene / butadiene copolymers, thiol-ene / acrylate copolymers , Polynorbornene, polymer networks made of poly (8-caprolactone) (PCL) and dimethacrylates, poly (8-caprolactone) (PCL) -based FGPs, acrylate-based FGPs, (meth) acrylate networks, cross-linked polyethylene, epoxide-based FGPs, a polyurethane / phenoxy blend or a polyurethan / polyvinyl chloride (PVC) blend.