MXPA00006563A - Flushable poly(ethylene oxide) films with balanced mechanical properties - Google Patents

Abstract

Flushable film compositions and methods of making flushable film compositions are disclosed. The film compositions comprise polyethylene oxide). The modification of the poly(ethylene oxide) can be accomplished by grafting polar vinyl monomers, such as poly(ethylene glycol) methacrylate and 2-hydroxyethyl methacrylate, onto poly(ethylene oxide). The modified poly(ethylene oxide) has improved melt processability and is used to melt process thin poly(ethylene oxide) films of less than 5 mils in thickness. Films can be produced that have balanced mechanical properties and that are water-dispersible and flushable.

Description

FILMS OF POLY (ETHYLENE OXIDE) DISPOSABLE WITH DISCHARGE OF WATER WITH MECHANICAL PROPERTIES BALANCED FIELD OF THE INVENTION The present invention is directed to poly (ethylene oxide) films. More particularly, the present invention is directed to films comprising a modified poly (ethylene oxide) composition. In a preferred embodiment, the films comprise poly (ethylene oxide) modified by the grafting of polar vinyl monomers and onto a poly (ethylene oxide).

BACKGROUND OF THE INVENTION Personal care products such as linings for panties, diapers, caps, etc., are of great convenience. Such products provide the benefit of a sanitary use at one time and are convenient because they are quick and easy to use. However, the disposal of many such products is a concern due to the limited land filling space. Incineration of such products is undesirable because of growing concerns about air quality and the costs and difficulties associated with separating such products from other non-incinerable discarded items. Consequently, there is a need for disposable products which can be quickly conveniently discarded without being thrown into the landfill d or by means of incineration.

It has been proposed to dispose of such products in the municipal and private drainage systems. Ideally, such products will be disposable with water discharge and will be degradable in conventional drainage systems. The suitable products for the disposal in the drainage systems and that can be discarded with discharge of water down in the conventional toilets are called disposable with discharge of water. L disposal by means of waste with discharge of agu provides an additional benefit of giving a convenient simple means and sanitary disposal. Personal care products must have sufficient strength under the environmental conditions in which they will be used, they must be able to withstand the elevated temperature and humidity conditions encountered during use and storage, but they must still lose their integrity. contact with the water in the toilet. Therefore, a water-disintegrable material, which is thermally processable and thin films having mechanical integrity when dry, is desirable.

Due to its unique interaction with water and body fluids, polyethylene oxide (hereinafter polyethylene oxide) can be used as a component material for disposable products with water discharge. Polyethylene oxide, - (CH2CH20) n-, is a commercially available water soluble polymer which can be produced from the ring opening polymerization of polyethylene oxide, Due to its water-soluble properties, polyethylene oxide is desirable for waste disposal applications. However, there is a dilemma in using polyethylene oxide in waste applications with water discharge.

The low molecular weight polyethylene oxide resins have desirable melt viscosity and melt viscosity properties for extrusion processing but have limitations when processing the melt and structural articles such as thin films. An example of a low molecular weight polyethylene oxide resin is the POLYOX® WSR N-80 which is commercially available from Union Carbide. The POLYOX® WSR N-80 has an approximate average molecular weight of 200,000 grams per mole as determined by melt rheology measurements. As used herein, low molecular weight polyethylene oxide compositions are defined as polyethylene oxide compositions with an average molecular weight of less than and including about 200,000 grams per mole.

In the industry for personal care, thin gauge films are desired for their commercial viability and ease of disposal. The low melt strength and low melt elasticity of the low molecular weight polyethylene oxide limit the ability of the low molecular weight polyethylene oxide to be pulled on films having a thickness of less than about 2 mils. Even when the low molecular weight polyethylene oxide can be thermally processed into films, thin gauge films of less than about 1 mil of thickness can not be obtained due to the lack of melt strength and the elasticity of the film. molten polyethylene oxide of low molecular weight. The processing of polyethylene oxide can be improved by mixing the polyethylene oxide with a second polymer, an ethylene copolymer of acrylic acid, in order to increase the strength of the melt. The ethylene / polyethylene oxide acrylic acid copolymer mixture can be processed in films about 1. thousandths of an inch thick. However, the mixture and the resulting film are not soluble in water. Most importantly, thin films made of low molecular weight polyethylene oxide are very weak and brittle to be useful for personal care applications. Low molecular weight polyethylene oxide films have low tensile strength, low ductility, and are brittle for commercial use. In addition, films made of low molecular weight polyethylene oxide and mixtures containing low molecular weight polyethylene oxide become brittle during storage at environmental conditions. Such films are broken and are not suitable for commercial applications.

High molecular weight polyethylene oxide resins are expected to produce films with improved mechanical properties compared to films produced from low molecular weight polyethylene oxide. An example of a higher molecular weight polyethylene oxide is POLYOX® WS 12K which is commercially available from Union Carbide. E POLYOX® WSR 12K has an approximate average molecular weight of 1,000,000 grams per mole as determined by meltdown measurements. As aguy were used, the higher molecular weight polyethylene oxide compositions are defined as polyethylene oxide compositions with an average molecular weight of more than and including about 300,000 gram per mole.

Higher molecular weight polyethylene oxide has poor processing due to its high melt viscosity and poor melt pull. The melt pressure melt temperature are significantly elevated during melt extrusion of high molecular weight polyethylene oxide. During extrusion of the higher molecular weight polyethylene oxide, a severe melt fracture is observed. Only very thick sheets can be made of higher molecular weight polyethylene oxide. The higher molecular weight polyethylene oxide can not be thermally processed into films of less than about 7 mils of an inch thickness. The higher molecular weight polyethylene oxide suffers from severe melt degradation during the extrusion process. This results in a breakdown of the polyethylene oxide molecules and the formation of bubbles in the extrudate. The inherent deficiencies of the higher molecular weight polyethylene oxide make it impossible to use the higher molecular weight polyethylene oxide in film applications. Still, the addition of the higher levels of plasticizer to the higher molecular weight polyethylene oxide does not improve the melt processing of the higher molecular weight polyethylene oxide sufficiently to allow the production of thin films without a melt fracture occurring. a movie break. In addition, the use of plasticizer causes latent problems due to the migration of the plasticizer to the surface of the film.

Therefore, the available polyethylene oxide resins are not practical for melt extrusion of thin films and for personal care applications. What is required in the art, therefore, are a means to overcome the difficulties in processing with molten polyethylene oxide resins currently available in films.

SYNTHESIS OF THE INVENTION To overcome the disadvantages of the prior art, this invention teaches a method for grafting polar functional groups into the polyethylene oxide in a melt. Modification of polyethylene oxide reduces melt viscosity, melt pressure and melt temperature. Additionally, the modification of the higher molecular polyethylene oxide according to the invention eliminates the severe melt fracture observed when the unmodified higher molecular weight polyethylene oxide is extruded. Films as thin as 0.3 to 0.5 mil may be processed using conventional processing techniques. Commercially available polyethylene oxide resins can not be made in thin films using conventional thermal processing techniques. Disposable polyethylene oxide films with thin water discharge are useful as components for personal care products and cold water soluble packaging materials.

The present invention is directed to films comprising modified polyethylene oxide compositions. More particularly, the present invention relates to films comprising modified polyethylene oxide which have improved processing over conventional polyethylene oxide resins., allowing both the modified polyethylene oxide to be thermally extruded into thinner films. Preferably, modification of the polyethylene oxide is achieved by grafting a polar vinyl monomer, such as a poly (ethylene glycol) 2-hydroxyethyl methacrylate methacrylate, into the polyethylene oxide. The graft is achieved by mixing the polyethylene oxide, the monomers and the initiator and applying heat.

Modification of polyethylene oxide allows thin calibrated films to be technically extruded from the modified polyethylene oxide and produce films with balanced mechanical properties in the same direction and in the transverse direction. Such balanced mechanical properties are not usual for films that are extruded uniaxially during the manufacture of films and therefore possess directional properties. Additionally, the global tensile properties of thin films are excellent, have high elongation at break, resistance to stress, energy at break.

As used herein, the term "graft copolymer" means a copolymer produced by the combining ability of two or more constitutionally or configurationally different feature chains, one of which serves as a column backbone, and at least one of which is attached at some point or points along the column and constitutes a side chain. As used herein, the term "graft" means forming a polymer during the joining of the chains or side surfaces or at some point along the column of a parent polymer. (See Sperlin L.H., Introduction to the Science of Physical Polymer 1986, page 44-47 which is hereby incorporated by reference in its entirety.

Currently, the available polyethylene oxide resins are not suitable for film applications. Low molecular weight polyethylene oxide resins of less than 300,000 grams / mol can be processed into films with thicknesses of about 1 to 2 mils but not any thinner due to the low melt strengths of the resins of low molecular weight. The films produced from the low molecular weight polyethylene oxide resins have voltage values of only up to 300% voltage values of only up to 3 MPa in the machine direction. In the transverse direction, the low produced films of the low melt strengths of the low molecular weight resins. Films produced from low molecular weight polyethylene oxide resins have tensile values of only up to 300 percent and tensile values of only up to 13 MPa in the machine direction. In the transverse direction, the films produced from the low molecular weight polyethylene oxide resins have voltage values of less than 75% and voltage values of only up to 12 MPa. In addition to the poor tensile properties, the films produced from the low molecular weight polyethylene oxide resins have a poor tear resistance and exhibit adverse decreases in properties with aging. Although the films produced from the unmodified higher molecular weight polyethylene oxide resins have better tensile properties, they can only be processed in thick sheets of greater thicknesses of about 7 mils. Even when these thicknesses, the films produced with unmodified higher molecular weight polyethylene oxide have very weak transverse direction properties and very low tear resistance. Therefore, films produced from unmodified polyethylene oxide resins are not desirable for films or for personal care applications.

In contrast, the modification of polyethylene oxide resins with molecular weights and start of around 300,000 grams per mole to about 8,000,000 grams per mole and produces polyethylene oxide compositions which can be pulled on films with thicknesses of less than 0.5 thousandths of an inch. Modification of polyethylene oxide resins with starting molecular weights of 500.00 grams per mole to about 8,000,000 grams per mole desirable and modification of polyethylene oxide resins with starting molecular weights of 800,000 grams per po mol to around 6,000,000 grams per mole are more desirable.

Films according to the invention contain better softness and clarity than films pulled from unmodified low molecular weight polyethylene oxide resins. The thermal processing of the modified polyethylene oxide films also produces films with improved mechanical properties on similarly processed films of unmodified polyethylene oxide resins.

These and other features and advantages of the present invention will become apparent after a review of the following detailed description of the embodiments. • described.

BRIEF DESCRIPTION OF THE FIGURES Figure 1 compares the melt rheology curve of a U unmodified polyethylene oxide resin. molecular weight of about 600,000 grams per mole example 1, and the melt rheology curves of modified polyethylene oxide composition of the polyethylene oxide resin of molecular weight of 300,000 grams per mole, example 2-5. Figure 2 compares the melting rheology curve of an unmodified polyethylene oxide resin of a molecular weight of about 1,000,000 grams per mole, example 6, melting rheology curves of acid compositions. modified polyethylene of polyethylene oxide resin of molecular weight of 1,000,000 grams per mole, example 7-10.

Figure 3 shows the results of the infrared Fourier transform analysis of the u-films unmodified polyethylene oxide of an approximate molecular weight of 600,000 grams per mole, example 1, a polyethylene oxide of an initial approximate molecular weight of 600.00 grams per mole modified with 4.9% by weight of HEMA and 0.28% d initiator , example 3; and a polyethylene oxide of an initial approximate molecular weight of 600,000 grams per mole modified by 4.9% by weight of PEG-MA and 0.32% of initiator, example 5.

Figure 4 compares a rheology curve of an unmodified polyethylene oxide resin of 600,000 gram per mole of approximate molecular weight, example 1, and the melting curves of the polyethylene oxide compositions of the polyethylene has an initial approximate molecular weight of 600,000 grams per mole with low initiator and monomer levels, examples 11-13.

Figure 5 compares the melt rheology curve of an unmodified polyethylene oxide of a molecular weight of about 300,000 grams per mole, example 14, and the rheology curves of the modified polyethylene oxide compositions of the polyethylene having an initial approximate molecular weight of 300,000 grams per mole, examples 15 and 16.

Figure 16 compares the melt rheology curve of an unmodified polyethylene oxide of 400,000 grams per mole of approximate molecular weight, example 17, and melting rheology curves of the polyethylene oxide modified initial polyethylene oxide compositions. having an initial approximate molecular weight of 400,000 grams per mole examples 18 and 19.

DETAILED DESCRIPTION The improved films can be co-melt processed using conventional commercially available polyethylene oxide resin methods when modified in accordance with this invention. Polyethylene oxide resins useful for modification include, but are not limited to, polyethylene oxide resins having approximate initial reported molecular weights of from about 300.00 grams per mole to about 8,000,000 grams per mole rheological measurements. . Such polyethylene oxide resins are commercially available from Union Carbide Corporation and are sold under the trade designations POLYOX® WSR N-205 and UCARFLOC® Polymer 309, respectively. Modification of polyethylene oxide resins starting molecular weights from 500,000 grams per mole to about 8,000,000 grams per mole is most desirable and the modification of polyethylene oxide resins with starting molecular weights of from around 800,000 grams per mole to around 6,000,000 are more desirable. Commercially available resins within the ranges include, but are not limited to, POLYOX® WSR N-205 and POLYOX® WSR N-12K.

Other polyethylene oxide resins available from Union Carbide Corporation within the approximate molecular weight ranges mentioned above are sold under the trade designations WSR N-750, WSR N-3000, WSR 3333, WS 205, WSR-N-12K, WSR-N-60K, WSR-301, WSR Coagulant, WSR-303 (See the work POLYOX®, Soluble Resins in Water by Union Carbid 'Chemical & Plástic Company, 1991 which is incorporated herein by reference in its entirety). Both the polyethylene oxide pellets and the polyethylene oxide powder can be used in this invention since the physical form of the polyethylene does not affect the behavior in the molten state for the graft reactions. This invention has been demonstrated by the use of polyethylene oxide d in the powder form, as supplied by Unio Carbide. However, the polyethylene oxide resins to be modified that are to be obtained from other suppliers in other forms such as pellets. The polyethylene oxide resins and the modified compositions may optionally contain various additives such as pacifiers, processing aids, rheology testers, antioxidants, ultraviolet stabilizers, pigments, dyes, slip additives, antiblocking agents, etc., which they can be added before or after the modification.

A variety of polar vinyl monomers may be useful in the practice of this invention. The monomer as used herein includes monomers, oligomers, polymers, mixtures of monomers, oligomers and / or polymers and any other reactive chemical species which are capable of covalent bonding with the parent polymer, polyethylene oxide. Ethylenically saturated monomers containing a polar functional group such as hydroxyl, carboxyl, amine, carbonyl, halo, thiol sulfonic acid, sulfonate, etc., are suitable for this invention are desirable. Desirable ethylenically unsaturated monomers include acrylates and methacrylates. Particularly desirable ethylenically unsaturated monomers containing a polar functional group are 2-hydroxyethyl methacrylate (hereinafter HEMA) and poly (ethylene glycol) methacrylates (hereinafter PEG-MA). A particularly desirable poly (ethylene glycol) methacrylate is poly (ethylene glycol) ethyl methacrylate. However, it is expected that a wide range of polar vinyl monomers will be able to impart the effects of 2-hydroxyethyl methacrylate and poly (ethylene glycol) methacrylate to polyethylene oxide and will be effective monomers for grafting. The amount of polar vinyl monomers in relation to the amount of polyethylene oxide can vary from about 0.1 to about 20% by weight of monomer to the weight of the polyethylene oxide. Preferably, the amount of the monomer should exceed 0.1% by weight in order to sufficiently improve the processing of the polyethylene oxide. More preferably, the amount of monomer should be at the lower end in the range described above, from 0.1 to 20% by weight, in order to decrease costs.

This invention has been demonstrated in the following examples by the use of 1-hydroxyethyl methacrylate and poly (ethylene glycol) methacrylate as the polar vinyl monomers. Both, 2-hydroxyethyl methacrylate and poly (ethylene glycol) methacrylate were supplied by Aldrich Chemica Company. The 2-hydroxyethyl methacrylate used in the examples was designated Aldrich catalog No. 12,863-5 and the poly (ethylene glycol) methacrylate was designated to Aldrich catalog No. 40,954 5. The poly (ethylene glycol) methacrylate was a poly (ethylene glycol) ethyl methacrylate ether having an average molecular weight d number of about 246 grams per mole. Poly (ethylene glycol) methacrylate with a number average molecular weight of greater than or less than 246 grams per mole is also applicable for this invention. The molecular weight of the poly (ethylene glycol) methacrylate can vary up to 50,000 grams per mole. However, the lower molecular weights are desirable for the faster graft reaction rates. The desirable molecular weight range of the monomers is from about 246 about 5,000 grams per mole and the most desirable range is from about 246 to about 2000 grams per mole. Again, it is expected that a wider range of polar vinyl monomers as well as a broad range of molecular weights of monomers are capable of imparting effects similar to polyethylene oxide resins and will be effective monomers for grafting and modification purposes.

A variety of primers may be useful in the practice of this invention. If the graft is achieved by the application of heat, as in the reactive extrusion process and preferable that the initiator generates free radicals through the application of heat. Such initiators are generally mentioned, thermal initiators. In order for the initiate to function as a useful source of radicals for grafting, and initiator must be commercially available, it must be stable at ambient or refrigerated conditions and general radical reactive extrusion temperatures.

Compounds containing a 0-0, S-S N = N bond can be used as thermal initiators. Compounds containing O-O bonds, peroxides are commonly used as initiators for polymerization. Such commonly used peroxide initiators include: alkyl, dialkyl, diaryl arylalkyl peroxides, peroxides such as cumyl peroxide, t-butyl peroxide, di-t-butyl peroxide, dicumyl peroxide, butyl cumyl peroxide, 1, 1- di-t-butyl, peroxide-3,5,5-trimethylcyclohexane, 2,5-dimethyl-2,5-di (butylperoxy) hexane, 2,5-dimethyl-2,5-bis (t-butylperoxy) hexino- 3 and bis (at-butyl peroxyisopropylbenzene); acyl peroxides such as acetyl peroxides and benzoyl peroxides; hydroperoxides such as cumyl hydroperoxides, t-butyl hydroperoxide, t-methane hydroperoxide, pinano hydroperoxide and eumeno hydroperoxide; peresters or peroxyesters such as t-butyl peroxypivalate, t-butyl peroctoate, t-butyl perbenzoate 2, 5-dimethylhexyl-2, 5-di (perbenzoate) and t-butyl di (pereftalate) alkylsulfonyl peroxides; dialkyl peroxymonocarbonates F dialkyl peroxydicarbonate; diperoxyketals; acetone peroxides such as cyclohexanone peroxide and methyl ethyl ketone peroxide. Additionally, azo compounds such as 2,2'-azobisisobutyronitrile abbreviated as AIBN, 2,2'-azobis (2,4-dimethylpentanenitrile) and 1,1'-azobis (cyclohexanecarbonitrile can be used as an initiator. in the following examples by the use of a liquid, an organic peroxide initiator available from Elf Atochem North Americ Inc., of Philadelphia, Pennsylvania, under the trade designation LUPERSOL® 101. LUPERSOL® 101 is a free radical initiator and It comprises 2,5-dimethyl-2,5-di- (t-butylperoxide) hexane Other initiators and other classes of LUPERSOL initiators can also be used as LUPERSOL® 130.

A variety of reaction vessels may be useful in the practice of this invention. The modification of Polyethylene acid can be carried out in any container as long as the necessary mixing of the polyethylene acid, monomer and initiator is achieved and provides sufficient thermal energy for the graft. Preferably, such containers include any suitable device, such such as Bradender Plasticorders, Haake extruders, single or multiple screw extruders or any other mechanical mixing devices which can be used to mix, process or manufacture polymers. In a preferred embodiment of the reaction device is a Haaker extruder twin screw extruder, available from 53 Wes Century Road, Paramus, New Jersey 07652 or a twin counter rotary screw extruder, such as twin screw combination extruder 30. ZSK manufactured by Werner & Pfleidere Corporation of Ramsey, New Jersey. It should be noted that a variety of extruders can be used to modify the polyethylene oxide according to the invention whenever mixing and heating occur.

The ZSK-30 extruder allows multiple supply has ventilation port and is capable of producing modified polyethylene oxide at a rate of up to 50 pounds per hour maximum of modified polyethylene oxide is desired, a commercial scale extruder ZSK-58 manufactured by Werner &; Pfleidere can be used. The ZSK-30 extruder has a pair of co-rotating screws arranged in parallel with a center-to-center distance between the axes of the two screws at 26.2 millimeters. The nominal screw diameters are 30 millimeters. The actual outside diameters of the screws are 3 millimeters and the internal screw diameters are 21. millimeters. The thread depths are 4.7 millimeters. The lengths of the screws are 1328 millimeters and the length of the total processing section was 1338 millimeters.

This ZSK-30 extruder had 14 processing barrels which are consecutively numbered / 14 barrel from the supply to the matrix for the purposes of this description. The first barrel, barrel # 1 received the polyethylene oxide and was not heated but cooled with water. The other 13 barrels were heated. The monomer, 2-hydroxyethyl methacrylate or poly (ethylene glycol) methacrylate was injected into barrel # 5 and the initiator was injected into barrel # 6. Both the monomer and the initiator were injected through the pressurized nozzle injector, also manufactured by Werner Pfleiderer. The order in which the polyethylene acid, the monomer and the initiator are added is not critical and the initiator can be added at the same time or in reverse order. However, the order used in the following examples is preferred. The matrix used to extrude the modified polyethylene oxide yarns has 4 openings of 3 millimeters in diameter which are separated by 7 millimeters. The modified polyethylene oxide threads are extruded in an air-cooled strip and then the extruded polyethylene oxide melt strands were pelletized by air on a fan-cooled conveyor belt of 20 pieces in length.

EXAMPLES Examples 1-21 have been demonstrated by the use of the ZSK-30 extruder as detailed above. For the following examples, the barrel temperatures of the extruder were set at 80 ° C for all seven zones of the extruder. The speed of • Screw was set at 300 revolutions per minute. The polyethylene oxide resin was fed to the extruder with a K-Tron gravimetric feeder at a rate of 20 pounds per hour. The selected monomer and initiator were fed by the ELDEX pumps in the extruder at the various rates reported in Table 1. Extrusion conditions, temperatures barrel current for the seven zones of the extruder, the temperatur • of polymer melt, melt pressure and percent d torsional force before reactive extrusion for each of the twenty examples and are reported in Table 2. Modified polyethylene oxide threads are cooled by air over a conveyor belt cooled with fan of 20 feet d length. The solidified threads were then pelletized in a Conair pelletizer available from Conair of Bay City, Michigan.

The percentages by weight of the components used in the examples were calculated in relation to the weight of the base resin, polyethylene oxide, unless indicated otherwise. In the following examples, different zinc polyethylene oxide resins of approximate molecular weight were used and tested; POLYOX® WS 25 205 polyethylene oxide having a reported initial approximate molecular weight of 600,000 grams per mole was used in examples 1-5, 11-13 and 20; POLYOX® WSR 12K polyethylene oxide having an initial approximate molecular weight of about 1,000,000 gram per mole was used in examples 6-10; POLYOX® WSR N-750 polyethylene oxide having an approximate molecular weight initiates having a reported initial weight of 300,000 grams per mole was used in examples 14-16; POLYOX® WS N-3000 polyethylene oxide having an approximate initial molecular weight of 400,000 grams per mole was used in examples 17-19; and polyethylene oxide POLYOX® WSR N-80 having a reported initial approximate molecular weight of 200,000 grams per mole was used in Example 21.

Additionally, two monomers, the -hydroxyethyl methacrylate and poly (ethylene glycol) methacrylate and various levels of monomer addition, ranging from as low as 0.80% by weight to as high as 5.00% by weight of monomer to the weight of the resin of Polyethylene oxide were used and tested in the examples. The relative amount of the initiator in the examples varied from 0.12 to 0.32 percent by weight of the initiator to the weight of the polyethylene oxide resin. The trade designation of polyethylene oxideof the monomer, and the amounts of polyethylene oxide of the monomer and initiator used in the examples are listed in Table 1. Examples 1 represent a control sample of the unmodified polyethylene oxide of the initial approximate molecular weight of 600,000 grams per mole Example 6 is presented to a control sample of the unmodified polyethylene oxide of an initial approximate molecular weight of one million grams per mole. Example 14 represents an unmodified polyethylene oxide control force of an initial approximate molecular weight of 300,000 grams per mole. Example 17 represents a control sample of the unmodified polyethylene oxide of the initial approximate molecular weight of 400,000 grams per mole. Example 20 represents a comparative example of polyethylene oxide of the initial approximate molecular weight of 600,000 grams per mole modified only by the monomer view without the initiator. And, Example 21 represents a comparative example of the unmodified polyethylene oxide of the initial approximate molecular weight of 200,000 grams per mole.

Although the invention has been demonstrated in the examples, it is understood that the polyethylene oxide, the polar vinyl monomer, the initiator and the conditions can be varied depending on the type of the modified polyethylene oxide composition and the desired properties .

TABLE 1 Components and Process Conditions of the Examples The actual processing conditions during the extrusion of the unmodified and modified polyethylene oxide examples listed in Table 1 were recorded and reported in Table 2. Two runs were made for each of the examples of extrusion - reactive 2,5 and 7-10 and are reported as the second values 2 '-5' and 7 '-10', respectively. Tj to T7 represent the actual barrel temperatures of the seven zones of the extruder during the extrusion of the examples. j corresponds to barrels # 2 and # 3, T2 corresponds to barrels # 4 and # 5, T3 corresponds to barrels # 6 and # 7, T4 corresponds to barrels # 8 and # 9, T5 corresponds to barrels # 10 and # 11, T6 corresponds to barrels # 12 and # 13 and T7 corresponds to barrel # 14, the matrix. Barrel # 1 was not heated and remained at ambient conditions. • 27 TABLE 2 fifteen 25 co CM m o When the unmodified higher molecular weight polyethylene oxide resins, examples 1 and 6, were extruded under the aforementioned processing conditions • above, the melt pressure during the extrusion of unmodified polyethylene oxide resin was very high. The melt pressure of the unmodified 600,000 molecular weight polyethylene oxide of Example 1 was 1770-1810 pounds per square inch and the melt pressure of the non-modified 1,000,000 molecular weight polyethylene oxide of Example 6 was 1540- 10 1660 pounds per square inch. The heating of the cut • Intense extruder made the melt temperatures of unmodified polyethylene oxide resins will be significantly increased by 24 and 29 ° C above the temperature of the extruder barrel at 180 ° C. The melt temperature increased to 204 ° C During extrusion, the unmodified 600,000 molecular weight polyethylene oxide of Example 1 was increased to 209 ° C during the extrusion of the non-modified 1,000,000 molecular weight polyethylene oxide of Example 6. These factors contributed to a • severe melt fracture and thermal degradation during the Extrusion of unmodified higher molecular weight polyethylene oxide resins resulting in the production of undesirable yarns. The undesirable threads were characterized by threads wider than those tried, and the threads, threads connected to beads and rough threads. 25 At an upper screw speed of 400 revolutions per minute, and at a lower yield of approximately 5-10 pounds per hour, the melt fracture was reduced to something. However, under these conditions, the degradation of the polyethylene oxide appeared to be more severe with significantly more bubbles coming off from the inside of the yarns as they left the matrix due to the increase in residence time in the extruder. The exiting polymer yarns had a foam-like appearance which is undesirable. In addition, the placement of the extruder at 5 pounds per hour is an extremely low placement and is not practical for commercial applications.

For grafting processes of modified higher molecular weight polyethylene oxide resins under the same conditions, examples 2-5 and 7-10, the melt fracture was not visible producing yarns with smooth surfaces. The melt temperatures were significantly reduced as shown in Table 2. The melt temperatures by grafting 2-hydroxyethyl methacrylate and poly (ethylene glycol) methacrylate to the polyethylene oxide powders POLYOX® WSR 205 of Examples 2-5 were in the range of 189 to 198 ° C, a reduction of 6 to 15 ° C compared to the melt temperature of the same polyethylene oxide resin without the grafting of example 1 at 204 ° C. The threads also appeared to undergo less degradation than the polymer threads that contained less bubbles and were significantly smoother as they left the matrix. Melting temperatures for the grafting of 2-hydroxyethyl methacrylate and poly (ethylene glycol) methacrylate to polyethylene oxide POLYOX® WSR 12K, Example 7-10 were also substantially reduced, down to the range of 183 to 191 ° C and comparison to 209 ° C without grafting, example 6, a reduction of 18 to 26 ° C. This reduction to the operating temperature also apparently reduced the degradation within the extruder as the polymer threads contained fewer bubbles as they exited the matrix as compared to the non-grafted polyethylene oxide resin.

Examples 14 and 17 showed some melt fracture and thermal degradation even if not as bad as was observed for examples 1 and 6. The most obvious problems with the extrusion of examples 14 and 17 were the high melt pressure, 1379 and 1659 pounds per square inch and the torsional force increased 33 and 33%. For the modified polyethylene oxide of examples 15, 16, 18 and 19, the molten pressure was reduced by more than 50% compared to the unmodified polyethylene oxide of the same starting molecular weight and the torsional force was slightly reduced for each one from 33% down to 26-28%. The melt temperature was reduced for these examples.

Example 20, POLYOX® WSR polyethylene oxide 205 modified by the addition of the initiator alone, showed a remarkable change in the melt extrusion compared to example 1, unmodified POLYOX® WSR 205 polyethylene oxide. The melt pressure was reduced from 1770-1890 pounds per square inch to 313 pounds per square inch. The torsion force was reduced from 32-36% to 26%. And the melting temperature was reduced from 204 ° C to 198 ° C. These changes are expected to have resulted primarily from the chemical degradation of polyethylene oxide in the presence of the free radical initiator, and the same chemical degradation mechanism that occurred for examples 2-5, 7-13, 15, 16, 18 and 19. However, because Example 20 was modified without the use of a monomer, the preferential reaction was cross-linked in position to the graft. The resulting material was filled with cross-linked gel particles, somewhat as large as 0.5 to 1 millimeter. The gels became useless to the resulting polyethylene oxide.

Cross-linked gels were not observed, or were significantly reduced in both size and number, for the modified polyethylene oxides. Examples 2-5, 7-13, 15-16 and 18-19. It is believed that the initiator preferably reacted with the monomer causing grafting and chain cleavage instead of cross-linking. The modified polyethylene oxides of Examples 2-5, 7-13, 15-16 and 18-19 have beneficial properties for thermal processing on thin films and are useful for producing commercially useful articles, such as disposable personal care products.

In general, the modified polyethylene oxide examples 2-5, 7-13, 15-16 and 18-19 exhibited a reduced function temperature and reduced pressure as compared to the corresponding unmodified higher molecular weight polyethylene oxide. This allowed easier and more economical processing of the polyethylene oxide. The appearance of the modified polyethylene oxide processed by extrusion according to this invention is greatly improved as compared to a modified higher molecular weight polyethylene oxide. The extruded polyethylene oxide yarns modified according to this invention are much smoother and much more uniform compared to the extruded yarns of the same initial unmodified polyethylene oxide. The smoothness and uniformity of the extruded yarn of the unmodified polyethylene oxide of Examples 2-5, 7-13, 15-16 and 18-19 is comparable to the smoothness and uniformity of the extruded yarns of the ethylene oxide of molecular molecular approximate much lower, but with greater mechanical properties of higher molecular weights.

Gel Permeation Chromatography Analysis The number average molecular weight (Mn), the weight average molecular weight (M ^, the average molecular weight- (M, and the polydispersity index (MW / M of the examples were determined by gel permeation chromatography (hereinafter GPC). Gel permeation chromatography analysis was carried out by American Polyme Standard Corporation of Mentor, OH, for the examples of Table 1 and also for POLYOX® polyethylene oxide powders. WS 205 and POLYOX® WSR 12K unmodified and non-extruded. The results of the gel permeation chromatography analysis are reported in table 3. The first two rows of table 3 report the results of the gel permeation chromatography analysis for polyethylene oxide powders POLYOX® WSR 205 and POLYOX® WSR 12K before extrusion. Examples 1 and 6 are the results of gel permeation chromatography analysis of the extruded unmodified polyethylene oxides POLYOX® WSR 205 and POLYOX® WSR 12K of examples 1 and 6 of Table 1, respectively. That is, examples 1 and 6 represent the extrusion of the POLYOX® polyethylene oxide resins mentioned above at 180 ° C, 300 revolutions per minute and 20 pounds per hour in the ZSK-30 extruder without the additions of either a monomer or an initiator. The other example numbers correspond to the respective example numbers in Table 1.

TABLE 3 Molecular Weights and Polydispersity Indexes Significant reductions in molecular weights and polydispersity indices were observed after the reactive extrusion of the polyethylene oxide of the monomer and the initiator in Examples 2-5 and 7-10 as compared to the modified extruded polyethylene oxide of the examples 1 and 6. Along with changes in molecular weight and in the polydispersity index, a vast improvement in processing was observed. The most notable change in the weight distribution was observed in the distribution of the polydispersity index, which decreased from 12.52 for the polyethylene oxide of 600,000 grams per mol not modified down to 4.07-5.16 for the same starting polyethylene oxide modified according to the invention and from 14.29 for the unmodified polyethylene oxide from 1,000,000 grams per mole down to 4.07-4.84 for the same starting polyethylene oxide modified according to the invention.

The gel permeation chromatography analysis was not carried out for examples 11-20. However, it is believed that the modified polyethylene oxides of Examples 11-13, 15-16 and 18-19 will have reduced average molecular weights of reduced weight and reduced polydispersity index compared to the corresponding unmodified polyethylene oxides. 10 • Analysis of Differential Scanning Calorimetry dß Thermal Properties The modified and unmodified polyethylene oxide compositions of examples 1-19 were analyzed for differential scanning calorimetry (DSC) to determine the differences in thermal properties between modified and unmodified polyethylene oxide resins. Example 20 was not analyzed with respect to differential scanning calorimetry because the polyethylene oxide of the • Example 20 modified without the addition of a monomer was determined as not useful for the manufacture of films. The melting points (Tm) and the enthalpy of melt values (? H) for examples 1-19 are reported in Table 4.

TABLE 4 Thermal Properties The melting points as determined by the differential scanning calorimetry of the modified polyethylene oxides of Examples 2-5 and 11-13 are lower than for the initial unmodified polyethylene oxide of Example 1. Similarly, the decrease in the melting points suitable for the modified polyethylene oxides of Examples 7-10 compared to the unmodified polyethylene oxide of Example 6 for the unmodified polyethylene oxide of Examples 15 and 16 in comparison to the non-modified polyethylene oxide. modified from Example 14 and for the unmodified polyethylene oxide d of Examples 18 and 19 as compared to the initial unmodified polyethylene oxide of Example 17 These measured decreases in the melting points in the modified polyethylene oxide are further evidence of the modification and are beneficial for thermal processing.

Melting Rheology Melt rheology tests for the resin compositions of approximate molecular weight of 600.00 grams per unmodified initial mole, example 1 and modified example 2-5, are given in figure 1. The melt curing curves for the resin compositions of initial approximate molecular weight of 1,000,000 grams per mole modified, example 6 and modified, example 7-10 are provided in Figure 2. The melt rheology curves for resin compositions of approximate initial molecular weight of 600,000 grams per mol not modified, example 1, modified, examples 11-13 are provided in the figure. The melt rheology curves for the resin compositions of initial approximate molecular weight of 300,000 grams per mol, modified, example 14 and modified, examples 15 and 16 are provided in figure 5. The melt rheology curves for the compositions of resin of approximate initial molecular weight of 400,000 grams per mol unmodified, example 17 modified, examples 18 and 19 are provided in figure 6 The results show that the melt viscosities of the modified polyethylene oxides are significantly reduced at low cut-off rates of 50-100 s "1 than the melt viscosities of the modified polyethylene oxide, eg the melt viscosity of the polyethylene oxide resin of approximate molecular weight of 1,000,000 12k n modified is from 6,433 Pa * s to 50 s "1 and the melt viscosity of the same 12k resin modified with 5% poly (ethylene glycol methacrylate and 0.32% Lupersol initiator 131 is 2882 Pa * ss "at the same cut rate, 50 s" 1. This is a reduction in the melt viscosity of 55%.

However, higher cutting rates, especially 500-2,000 s "1, the melt viscosities of the modified polyethylene oxides appear to be comparable higher than the melt viscosities of the unmodified polyethylene oxide.The melt viscosity of the resin 12k modified n was 175 Pa * s 2,000 s "1 and the melt viscosity of the same 12k resin modified with 5% poly (ethylene glycol) methacrylate and 0.32% Lupersol 101 initiator is 316 Pa * s the same cutting rate, 2,000 s "! This is an increase in melt viscosity of 15%.

In general, the inclinations, of the rate of cort against the apparent viscosity decreased after the modification.

• NMR analysis The modified polyethylene oxide of the examples was analyzed by NMR spectroscopy. The results of this analysis confirmed that the modified polyethylene oxide of In fact, it contained 2-hydroxyethyl methacrylate or poly (ethylene glycol) methacrylate units grafted as side chains on the polyethylene oxide column. By NMR spectroscopy, it was determined that the polyethylene oxides produced in Examples 2-5, 7-13, 15-16 and 18-19 which contained 0.65 to 2.58 per percent of 2-hydroxyethyl methacrylate or poly (ethylene glycol) methacrylate side chains and 0 to 2.39 percent unreacted or ungrafted 2-hydroxyethyl methacrylate or poly (ethylene glycol) methacrylate.

Film Setting Process The unmodified polyethylene oxide resins of examples 1, 6, 14, 17 and 21 were pelleted and attempts were made to process these oxide resins of extruded polyethylene unmodified in thin films. For film processing, a Haake twin counter-rotating screw extruder was used with either a 4-inch or 8-inch wide film anchor. The temperature profile for the heating zones of the Haak extruder was 170, 180 and 190 ° C. The screw speed was adjusted in the range of 15-50 revolutions per minute depending on the thickness of the film attempted. The screw speed and the rolled speed were adjusted so that a film with a thickness within the range of 2-4 mils was produced. The process was allowed to stabilize so that the film samples could be collected or observed. The extruded films were collected on a rolled and cooled roller maintained at 15-20 ° C.

The Haake extruder was used to forge the films of the polyethylene oxide compositions was a twin counter-rotating screw extruder that contained a pair of counter-taper conical screws tailored with the 4-inch wide film die holder. The Haake extruder comprised 6 sections as follows: section 1 comprised a double-vane front pumping section having a large screw tilt and a high helix angle. The section comprised a double-vane forward pumping section having a smaller screw tilt than section 1. Section 3 comprised a double vane forward pumping section having a smaller screw tilt than section 2 Section 4 comprised a section of reverse pumping with notches and double vane e where a full blade is notched. Section 5 comprised a forward pumping section of double vane and notched • which contained two complete palettes. Section 6 comprised the double-vane forward pumping section having an intermediate screw inclination of section 1 and section 2. The extruder had a length of 300 millimeters. Cad conical screw had a diameter within 30 millimeters to a supply port and to a diameter of 20 millimeters in the matrix. Even though the extruder mentioned above is described in detail it should be noted that a variety of extruders must be used to process the polyethylene oxide films.

Extruded polyethylene oxide resins do not modified from examples 1 and 6 were not able to be processed into thin films of only thick sheets of a thickness greater than about 7 mils were able to be produced. Even these thick sheets exhibited a severe melt fracture. Stiffness and melt fracture of the leaves gave the leaves an appearance of undesirable closure type with sharp teeth on the edges. The unmodified polyethylene oxide resins were not capable of being thermally processed into thin films under normal processing conditions. The unmodified extruded polyethylene oxide resin of Example 14 having the lowest weight of the highest molecular weight polyethylene oxide resins tested, was the most processable of the modified higher molecular weight polyethylene oxides. However, the unmodified polyethylene oxide of example 14, polyethylene oxide POLYOX® WSR N-750 with an initial approximate molecular weight of 300,000 grams per mole was still very difficult to process a uniform sheet about 4 mils thickness. All attempts were processed in a film less than 4 thousandths of an inch thick resulting in a break, emergence and very uneven films. The film of minimum thickness that was capable of being processed from the polyethylene oxide of 400,000 grams per unmodified mol of Example 17 was only about 5 mils. The polyethylene oxide composition of Example 20 can be unprocessed in a film about 3-4 mils thick. However, the 3-4 mil polyethylene oxide films of Example 20 which contained numerous fish eye holes. Even though the torsional force and pressure during processing of the films of Example 20 were low, the films contained so many gel inclusions, that the gel inclusions propagated defects in the films. At less than 3-4 thousandths of an inch, the fish eye holes became so large that they became connected and caused breaks in the films.

The unmodified polyethylene oxide which was capable of being processed from a thin film was polyethylene oxide POLYOX® WSR N-80 of 200,000 grams per mole of molecular weight under example 21. However, the processed film 5 Modified low molecular weight polyethylene of Example 21 possess insufficient mechanical properties, such as low tensile strength and low ductility also exhibited increased breakage during storage under ambient conditions.

Additionally, the polyethylene oxide film does not • modified from Example 21 contained undesirable grainy particles. These deficiencies made unmodified polyethylene oxide resins without practices for commercial use in personal care products. In contrast, the films were successfully processed from the extruded modified polyethylene oxide compositions. The films were processed by melting the polyethylene oxide compositions of Examples 2-5, • 20 7-13, 15-16 and 18-19 using the same processing apparatus under conditions as intended for the processed films of the unmodified polyethylene oxide compositions. Examples 1, 6, 14, 17, 20 and 21 as detailed above. Uniform films of about 3 thousandths of an inch thickness were made. The screw speed, the torsional force and the matrix temperature composition for the processing of the films of the examples were measured and the averages of the measurements are reported in table 5.

TABLE 5 Movie Processing Conditions Attempts were made to process the films with acceptable solid state properties of the higher molecular weight modified polyethylene oxide resins. These attempts were made using the modified POLYOX® WSR 205 polyethylene oxide and the modified POLYOX® WSR 12K polyethylene oxide, the approximate molecular weights of 600,000 grams per mole and 1,000,000 grams per mole, respectively. POLYOX® WSR 12K polyethylene oxide can not be processed in a film. Therefore, the torsional force data n was collected for polyethylene oxide POLYOX® WSR 12K Example 6 of Table 5. The modified POLYOX® WSR 20 polyethylene oxide could not be extruded at lower screw speeds. The torsional force and pressure observed during the film processing of the POLYOX® WSR 205 polyethylene oxide compositions of Examples 2-5 were dramatically reduced as compared to the unmodified POLYOX® WS 205 polyethylene oxide of Example 1. The resin of unmodified higher molecular weight polyethylene oxide were found to be inpractical for the extrusion of thin films due to poor melt processing, lack of ability to be processed into films about 7 mils thick. Therefore, the unmodified high molecular weight polyethylene oxide resins are inpractical for melt processing.

In contrast, the modified polyethylene oxide compositions were capable of being melt processed into films with thicknesses of less than 0.5 thousandths without tearing or breaking. This is a significant improvement compared to the thicknesses of about 7 mils for the films of the unmodified higher molecular weight polyethylene oxides of examples 1 and 6. The grafting of the polar vinyl monomers in the oxide of Polyethylene transforms melting properties and processing, improving processing by increasing melt strength and melt pulling of polyethylene oxide, thus allowing thin films to be processed easily and quickly. This is also an improvement to the difficulties of processing a film of less than one thousandth of an inch of an unmodified low molecular weight polyethylene oxide such as Example 21 which possesses desirable processing conditions of low torsional force, pressure and temperature. matrix that increases desirable mechanical properties in a usable film.

The modified polyethylene oxide compositions in Examples 11-13 with the lowest levels of monomer adhesion processed comparably to the modified polyethylene oxide compositions of Examples 2-5 also exhibited reduced processing pressure and torsional force in comparison to modified polyethylene oxide processed under similar conditions. The modified polyethylene oxide compositions of examples 15 and 16 also exhibited a significantly reduced torsional force and a slightly reduced pressure and matrix temperature during processing as compared to the modified polyethylene oxide of the example when processed under similar conditions. Generally, melt viscosity during film processing I modified polyethylene oxide compositions was reduced and die pressure was reduced by more than 50%.

Very thin films were capable of processing the modified polyethylene oxide compositions of examples 15 and 16, exhibiting excellent processing. By contrast, unmodified POLYOX® WSR 750 polyethylene oxide having an approximate molecular weight starting at 300,000 grams per mole was not able to be processed into a film less than 4 mils thick and was broken or arose and became uneven in thickness during attempts to process the films to 4 mil thicknesses. Similarly, the modified polyethylene oxide compositions of Examples 18 and 19 also exhibited a significantly reduced pressure and torsional force and a slightly reduced matrix temperature during processing. and comparison to the unmodified polyethylene oxide of example 1 when processed under similar conditions and were able to be processed into very thin films exhibiting excellent processing. In contrast, the unmodified POLYOX® WSR N-3000 polyethylene oxide of Example 17 was not able to be processed into a film less than 5 thousandths of an inch thick and produced 5 mil films with similar toothed edges. to those observed from example 1.

In general, the modified polyethylene oxide films did not stick to the cooling roller. The modified polyethylene oxide films produced were smooth and soft and did not contain any grainy particles as did the films extruded from the unmodified low molecular weight polyethylene oxide of Example 21. The films produced from the modified polyethylene oxide compositions generally they had a better smoothness, smoothness, greater clarity than similarly produced films of unmodified polyethylene oxide compositions. Therefore, it has been found that the films of the modified polyethylene oxide compositions exhibited a significantly improved film processing and can be more easily and economically processed into thin films useful for personal care applications in contrast to the films of the modified n-polyethylene oxide compositions.

Stress Properties of Modified Polyethylene Oxide Films.

Stress tests were carried out on the films produced from the compositions of Examples 12-13, 15, 16, 18-20 and the POLYOX® WSR N-80 polyethylene oxide resin as detailed above. The tensile properties of one of the films was tested and measured in the machine direction (MD) and in the transverse direction (CD) and is presented in table 6.

TABLE 6 Movie Tension Properties The processed films of the unmodified POLYOX® WSR N-80 polyethylene oxide resin of Example 21 possessed low breaking elongation values. The mechanical properties of polyethylene oxide film POLYOX® WSR N-80 were tested and measured within 24 hours of film processing and are expected to decrease considerably with aging. Only the thick films are capable of being processed from the unmodified POLYOX® WSR 12K polyethylene oxide resin of Example 6. None of the properties in the transverse direction can be measured for the films of Example 6 due to the large variations in the thicknesses in the transversal direction of the films.

The mechanical properties of the processed films of four ethylene oxide compositions, examples 2-5, modified from the polyethylene oxide resins having a molecular weight of 600,000 grams per mole before the modification were tested. These films have high breaking elongation values ranging from 570 to 736%. These modified polyethylene oxide compositions have molecular weights and molecular weight distributions similar to the molecular weights and the molecular weight distributions of the unmodified POLYOX® WSR N-80 polyethylene oxide but have significantly improved mechanical properties compared to the processed films. of this unmodified low molecular weight polyethylene oxide resin. It is believed that these improved mechanical properties are brought at least in part by increased interchain interactions between the modified polyethylene oxide chains introduced by the grafting of the 2-hydroxyethyl methacrylate and poly (ethylene glycol) methacrylate polyethylene oxide. Additionally, it is believed that the grafted polar groups result in the hydrogen bonding between the neighboring polyethylene oxide chains by linking the chains in both the molten and solid state.

Even in the modification of polyethylene peroxide resins with low levels of monomers produces improved mechanical properties. This is demonstrated by the high elongation at break, at the peak voltage and at the energy measurements at break observed in examples 11, 12 and 13. Grafting even at low levels improves the elemental properties of polyethylene oxide thereby allowing the Thin films when processed from polyethylene oxide.

In general, the processed films of the modified polyethylene oxide compositions found that they had improved mechanical properties over the similarly processed films of the conventional resins. Modified polyethylene oxide films showed dramatic improvements in tensile properties, greater than 600% in tension and 200% in effort in machine direction and greater than 1400% in tension of 200% in effort in the transverse direction. Additionally, the films produced from the modified polyethylene oxide compositions observed that they had balanced properties in the direction of the machine against the transverse direction. These films exhibited improved high peak voltages and d energy values at break. More importantly, the films have reduced modulus values which showed their improved flexibilities compared to the unmodified polyethylene oxide films. The improved flexibility of films containing modified polyethylene oxide is particularly desirable for applications for waste disposal with water discharge and specifically for disposable personal care products with water discharge.

Qualitative Analysis FT-IR Fourier transformation infrared spectroscopy analysis (FT-IR) was carried out on the processed thin films of the compositions of examples 1,3 and 5. The aspects that were obtained from this analysis are shown in figure 3. lower line is the spectrum observed for example 1, polyethylene oxide of an approximate molecular weight of 600,000 grams per mol not modified and extruded. The middle line is the spectrum observed for Example 3, the polyethylene oxide of approximate molecular weight of 600,000 grams per mole grafted with 5% of 2-hydroxyethyl methacrylate. And the top line is the spectrum observed for Example 5, the polyethylene oxide of 600.00 grams per mole of approximate molecular weight grafted with 5% of poly (ethylene glycol) methacrylate.

The small peaks observed at 1,725 cm'1 in the upper and middle aspects of examples 5 and 3 respectively are the absorption peaks for poly (ethylene glycol methacrylate and 2-hydroxyethyl methacrylate respectively) This peak absorption at approximately 1,750 cm ' 1, was not observed for unmodified polyethylene oxide as shown in the lower spectr in Figure 3.

Crystal Morphology Polyethylene oxide film POLYOX® WS 205 unmodified having an approximate molecular weight starts reported of 600,000 grams per mole of Example 1 and the film produced from the modified sample of the same starting resin was analyzed using polarized light microscopy. In addition to being of a greater thickness, the unmodified film possessed spherulite crystals larger than the film produced from modified polyethylene oxide under the same processing conditions. Spherulites in the unmodified sample were observed as being of the order of 20 to 50 microns in size, while the spherulites in the modified sample were not observable under the same amplification and are believed to be in the order of less than 1 miera in size. The crystalline structures of the films changed dramatically due to grafting. It is believed that the improved mechanical properties of the films containing modified polyethylene oxide were brought at least in part by the changes in crystal morphology. Additionally, the resistance of the films modified to the physical aging was expected to improve as a result of the observed improvement in the crystal structure.

Although it is not desired to be bound by the following theory, it is believed that during the extrusion-reactive processing of the polyethylene oxide resins, the peroxide initiator initiated three competitive reactions: 1) the grafting of the vinyl monomer in the polyethylene oxide, 2) degradation of polyethylene oxide, and 3) cross-linking of polyethylene oxide. A novel method to achieve the improved properties has been the developed one that is contrary to the traditional methodology and to the thought in the development of polymer. The method degrades the polymer into shorter chains as opposed to only increasing molecular weight. The resulting modified polyethylene oxide compositions have improved melt strength and melt elasticity, overcoming the inherent deficiencies of both low molecular weight polyethylene oxides and higher molecular weight polyethylene oxide. These improved melt properties allow modified polyethylene oxide to be processed into useful films with thicknesses of less than 0.5 mils d inch and with improved and balanced tensile properties.

The present invention has been illustrated in detail by the specific examples given above. It is understood that these examples are illustrative embodiments and that this invention should not be limited by any of the example details of the description. Those skilled in the art will recognize that the present invention is capable of many modifications and variations without departing from the scope of the invention. Therefore, the detailed description and the examples are intended to be illustrative and are not intended to limit in any way the scope of the invention as set forth in the following claims. Rather, the appended claims herein should be broadly considered within the spirit scope of the invention.

Claims (20)

R E I V I N D I C A C I O N S

1. A film comprising poly (ethylene oxide) that is water dispersible, melt processable, and has an average thickness of no more than about 5 thousandths of an inch.

2. The film as claimed in clause 1, characterized in that the film consists essentially of poly (ethylene oxide) crystals having an average diameter of less than 10 microns.

3. The film as claimed in clause 1, characterized in that the film is based on poly (ethylene oxide).

4. A film comprising a modified poly (ethylene oxide).

5. The film as claimed in clause 5, characterized in that the poly (ethylene oxide) has an initial molecular weight before modification within the range of about 300,000 grams per mole to about 8,000,000 grams per mole mol.

6. The film as claimed in clause 5, characterized in that the poly (ethylene oxide) has an initial molecular weight before modification within the range of about 500,000 grams per mole to about 8,000,000 grams per mole mol.

7. The film as claimed in clause 6, characterized in that the poly (ethylene oxide) has an initial molecular weight before modification within the range of about 800,000 grams per mole to about 6,000,000 grams per mole mol.

8. The film as claimed in clause 5, characterized by the poly (modified ethylene oxide) is modified by the addition of an initiator.

9. The film as claimed in clause 5, characterized in that the modified poly (ethylene oxide) is modified by the addition of a monomer and initiator.

10. The film as claimed in clause 9, characterized in that the monomer is a polar vinyl monomer.

11. The film as claimed in clause 10, characterized in that the polar vinyl monomer selected from the group consisting of poly (ethylene glycol) methacrylates and 2-hydroxyethyl methacrylate.

12. The film as claimed in clause 11, characterized in that the polar vinyl monomer is a poly (ethylene glycol) ethyl ether methacrylate and has an average molecular weight of no more than about 5,000 grams per mole.

13. The film as claimed in clause 9, characterized in that the monomer is added within the range of about 0.1 to about 20% by weight relative to the weight of the poly (ethylene oxide).

14. The film as claimed in clause 5, characterized in that the modified poly (ethylene oxide) is a grafted poly (ethylene oxide).

15. The film as claimed in clause 5, characterized in that the modified poly (ethylene oxide) has a polydispersity index of less than 10.

16. The film as claimed in clause 5, characterized in that the modified poly (ethylene oxide) has a melt temperature of less than 68 degrees. • centigrade

17. A method for processing poly (ethylene oxide) films comprising: adding a poly (ethylene oxide), a monomer and an initiator to a reaction vessel; mixing the poly (ethylene oxide), the monomer and the initiator under conditions sufficient to graft the monomer to the poly (ethylene oxide); and pulling a film of the poly (ethylene oxide) inert.

18. The method as claimed in clause 17 characterized in that the monomer is a polar vinyl monomer.

19. The method as claimed in clause 18, characterized in that the polar vinyl monomer is 25 selected from the group consisting of poly (ethylene glycol) methacrylates and 2-hydroxyethyl methacrylate.

20. A film produced by the method as claimed in clause 17. • • • E S U M E N Disposable film compositions with water discharge and methods for making disposable film compositions with water discharge are described. The film compositions comprise poly (ethylene oxide). Modification of poly (ethylene oxide) can be achieved by grafting polar vinyl monomers, such as poly (ethylene glycol) methacrylate and 2-hydroxyethyl methacrylate, on poly (ethylene oxide). The modified poly (ethylene oxide) has an improved melt processing and is used for the melting process of thin poly (ethylene oxide) films less than 5 mils in thickness. The films can be produced having balanced mechanical properties and are disposable and dispersible with water discharge.