Abstract:
A method for preparing a compatible blend of polyolefin and thermoplastic polyvinyl alcohol comprising: 
     (a) melting polyolefin in the initial elements of a melt extruder, 
     (b) adding and melt blending an unsaturated carboxylic acid or anhydride with the melted polyolefin downstream in the extruder, 
     (c) adding peroxide to the melt blend and grafting the unsaturated carboxylic acid or anhydride onto the polyolefin, and 
     (d) melt blending thermoplastic PVOH into the grafted polyolefin/unsaturated carboxylic acid or anhydride melt mixture.

Description:
TECHNICAL FIELD 
     The present invention relates to melt extrudable blends of polyolefins and thermoplastic polyvinyl alcohol (PVOH) and, more particularly, relates to reactive extrusion grafted blends of polyolefins and thermoplastic PVOH. 
     BACKGROUND OF THE INVENTION 
     One of the more useful methods to modify polymers involves blending them with other polymers of different structures and properties. In fact, the subject of polymer blends has been one of the key research and development areas in the field of polymers in the past decade. In a few cases, polymer blend combinations are miscible, i.e., they exhibit thermodynamic miscibility and are mixed at the scale of molecular dimensions. These blends are mechanically compatible. 
     However, most blends are phase separated and generally exhibit poor mechanical compatibility. Phase separated systems in several cases can exhibit mechanical compatibility where the polymer compositions are similar, e.g., polyolefin blended with other polyolefins, or where interfacial agents are added to improve the compatibility at the interface between the constituents of the polymer blend. 
     For blends of polyolefins and PVOH, the extremes in polymer compatibility are expectedly observed. Polyolefins are very water insensitive whereas PVOH dissolves in water. Polyolefins are sensitive to hydrophobic compounds, e.g. oils and grease, whereas PVOH is very resistant. 
     Polymer blends of polyolefins and thermoplastic PVOH are melt processible, however, they exhibit very poor mechanical compatibility. This poor mechanical compatibility is manifested in the mechanical property profile of the blends relative to the properties of the unblended constituents where the blends suffer significantly in elongation at break, tensile strength and toughness. In addition, the blends exhibit non-homogeneity as noted in the injection molded surface and topology of the fractured samples for mechanical testing. 
     The utility of polyolefin/thermoplastic PVOH blends, if mechanical compatibility could be achieved, can be envisioned for many applications including barrier films, foam, injected molded articles and extrusion applications. The potential utility of polyolefin/thermoplastic PVOH blends has been noted in the patent literature. These patents note the poor mechanical compatibility of polyolefins and thermoplastic PVOH and many note various approaches towards solving this deficiency. Thus, modifications of polyolefin/thermoplastic PVOH blends are necessary in order to obtain useful properties. 
     U.S. Pat. No. 4,600,746 discloses the compatabilization of PVOH with a functional polymer, i.e., polyolefin or an ethylene-ester copolymer with groups capable of reacting with the hydroxyl of PVOH, e.g. carboxylic acid, anhydride, for barrier polymer blends. Ethylene-acrylic acid, ethylene-methacrylic acid, ionomers, and maleic anhydride grafted polyolefins are disclosed in blends with PVOH as melt processible alloys. 
     U.S. Pat. No. 4,950,513 discloses a laminate of a polyolefin, a melt blend of a polyamide and a PVOH, and an alkyl carboxyl-substituted polyolefin. The laminate is used as a barrier film composition. 
     U.S. Pat. No. 4,806,597 discloses a blend of an aromatic polycarbonate, polyolefin, ethylene-vinyl alcohol copolymer and a hydrogenated styrene/butadiene block copolymer modified with unsaturated dicarboxylic acid or anhydride. 
     U.S. Pat. No. 4,362,844 discloses a biaxially stretched mixture of polypropylene and an ethylene-vinyl alcohol copolymer. Coupling agents proposed to improve the compatibility include maleic anhydride or acrylic acid grafted polypropylene or ethylene-acrylic acid copolymers. 
     The above references disclose various methods involving modification of olefins to improve compatibility with PVOH. These methods comprise including polar groups in the polyolefin structure or potentially reactive groups, for example, carboxylic acid or anhydride functionality. 
     Borggreve, R. J. M., et al, &#34;Brittle-Tough Transition In Nylon-Rubber Blends: Effect Of Rubber Concentration And Particle Size&#34;, POLYMER, 1987, Vol 28, August, (1489-1496) discloses a one-pass extrusion operation for polyolefin compatibilization with polyamides where the maleic anhydride is grafted to polyolefins utilizing peroxide. 
     SUMMARY OF THE INVENTION 
     The present invention provides a single pass, melt reactive extrusion compatibilization of polyolefin and a PVOH. The melt reactive grafting of unsaturated acids or anhydrides to polyolefins followed by reaction with thermoplastic PVOH provides mechanical compatibility which affords significant advantages over the prior art where a pregrafted polyolefin is mixed in a melt blending operation with the PVOH. 
     Specifically, the method for preparing a compatible blend of polyolefin and thermoplastic PVOH by single pass, melt reactive extruding comprises: 
     (1) melting polyolefin in a melt extruder; 
     (2) melt blending an unsaturated carboxylic acid or anhydride into the melted polyolefin; 
     (3) adding a free radical source to the melt blend and grafting the unsaturated carboxylic acid or anhydride onto the polyolefin; 
     (4) melt blending thermoplastic PVOH into the grafted polyolefin/unsaturated carboxylic acid or anhydride melt mixture, and optionally; 
     (5) extruding through a die; and 
     (6) cooling and pelletizing. 
     Advantages of the single pass reactive melt extrusion compatibilization procedure include the following: 
     (a) uniformity of the blend leading to improved water resistance; 
     (b) the residual unsaturated carboxylic acid or anhydride can react with PVOH or plasticizer containing hydroxyl groups and thus not yield problems associated with residual material that will result if the constituents were prepared separately; and 
     (c) an economic advantage in conducting the single reactive extrusion process instead of preparing, pelletizing and reextruding the grafted polyolefin with thermoplasic PVOH; 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The mechanical and visual compatability of blends of thermoplastic PVOH and various polyolefins is very poor. The present invention provides for the melt reactive extrusion grafting of an unsaturated carboxylic acid or anhydride onto the polyolefin followed by melt mixing with a thermoplastic PVOH in a single pass, thus eliminating the need to prepare a grafted polyolefin and recovering the product only to reextrude it with the thermoplastic PVOH in a second operation. 
     &#34;Reactive extrusion&#34; is the use of chemical reactions during polymer extrusion to form desired products. Free radical initiators, crosslinking agents, and other reactive additives can be injected into the extruder to cause these reactions. 
     The melt extruder used in the present extrusion operation is designed to conduct several operations during the preparation of the blends. The polyolefin is fed into the initial elements of the extruder. After melting the polyolefin in the initial elements, the unsaturated carboxylic acid or anhydride is fed into the extruder and, further down the extruder barrel, a free radical source such as a peroxide is fed to the extruder to yield improved grafting efficiency. After a length of extrusion sufficient to accomplish polyolefin grafting of the acid or anhydride, i.e., sufficient time, the thermoplastic PVOH is fed to the molten, grafted polyolefin stream either as pellets or powder through an open throat to the extruder or as a molten stream fed through a side stream extruder. After melt consolidation of the grafted polyolefin/thermoplastic PVOH blend, a vacuum port can optionally be used to removed ungrafted or unreacted maleic anhydride. Optionally, additional PVOH plasticizer can be pumped into the extruder after the vacuum port as makeup for any devolatilized PVOH plasticizer, if a low boiling plasticizer has been used. 
     The resulting reactive melt extrusion, compatibilized blend is extruded through die(s) at the end of the extruder and cooled on a chilled belt and pelletized, all procedures well known in the art. Water cooling can be used where higher levels of polyolefin are present in the blend, e.g., greater than 50% volume fraction. 
     While the above procedure is the preferred embodiment, other single pass extrusion conditions can be employed. Such processes would involve the addition of the acid or anhydride and peroxide at the same location along the extruder. 
     The polyolefins suitable for use in the present invention include polypropylene, polyethylene (including high density polyethylene, medium density polyethylene, low density polyethylene, linear low density polyethylene and linear very low density polyethylene), poly(butene-1) and ethylene-propylene rubber. Such polyolefins would have average molecular weights ranging from 20,000 to 2,000,000, preferably 50,000 to 700,000. Such polyolefins would have melt index values [44 psi (3.1 kg/cm 2 ), 190° C.] of 0.01 to 200 dg/min, preferably 0.5 to 40 dg/min. 
     The polyethylenes contemplated can be copolymerized with propylene, butene, hexene, octene and the like to achieve the various densities available for these materials. Ethylene copolymers such as ethylene-methyl acrylate copolymers, ethylene-ethyl acrylate copolymers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers and ionomers, and ethylene-methacrylic acid copolymers and ionomers are additional polyolefins suitable for this invention. Also considered as a polyolefin for purposes of this invention are styrene-ethylene/butylene-styrene ABA block copolymers of greater than 50 wt % of the ethylene/butylene block. 
     The polyolefin content of the polyolefin/thermoplastic PVOH blend is 10-80 wt %, preferably 25-75 wt %. 
     A thermoplastic PVOH is required in the present process. As noted in a recent review of PVOH given by F. L. Marten in the Encyclopedia Of Polymer Science And Engineering, Second Ed., Vol 17, p 167, John Wiley &amp; Sons, New York, 1989, several patents claim the preparation of extrudable PVOH using high boiling, water-soluble organic compounds containing hydroxyl groups. These compounds, for example glycerol, low molecular weight polyethylene glycols, are plasticizers which lower the melting point of PVOH into a processible range. Other suitable plasticizers such as sulfonamides are suitable if they are high boiling and miscible with PVOH. 
     The preferred thermoplastic PVOH for use in the present process, however, is that disclosed in U.S. Pat. No. 5,051,222 which is incorporated by reference. U.S. Pat. No. `222 discloses a thermoplastic PVOH prepared by a melt extrusion process which comprises adding sufficient energy to the PVOH (preferably with a plasticizer) to both melt the PVOH and essentially eliminate the crystallinity in the melt while simultaneously removing energy from the melt at a rate sufficient to avoid decomposition of the PVOH. Such thermoplastic PVOH&#39;s are commercially available from Air Products and Chemicals, Inc. under the VINEX trademark. 
     Suitable PVOH&#39;s have a 70-99+ mole % hydrolysis, preferably 78-94 mole %, and a degree of polymerization of 200 to 4000, preferably 300 to 1500. 
     In addition to plasticizers, the thermoplastic PVOH can contain other water soluble polymers such as poly(vinylpyrrolidone), poly(ethyloxazoline) and poly(ethylene oxide). 
     Also suitable as the thermoplastic PVOH are the hydrolysis product of a vinyl acetate copolymer which is at least 70 wt % vinyl acetate, especially ethylene-vinyl alcohol copolymers since they also exhibit poor mechanical compatibility with polyolefins. Ethylene content of up to 30 wt % can be used. These copolymers are produced by the hydrolysis of ethylene-vinyl acetate copolymers using methods similar to that for PVOH and are readily available commercially. Hydrolysis levels (based on vinyl acetate) of greater than 70 mole % are desired. 
     The amount of thermoplastic PVOH in the blend is 20-90 wt %, preferably 25-75 wt %. 
     Of the unsaturated carboxylic acids and anhydrides that are used for compatibilization of the polyolefin/thermoplastic PVOH blends, maleic anhydride is the preferred material. However, vinyl-containing carboxylic acids, such as acrylic acid or methacrylic acid can also be used, as can be mixtures of maleic anhydride and such carboxylic acids. The amount of the carboxylic acid or anhydride used will vary with the polyolefin selected, however, a range of 0.1 to 4 wt % based on polyolefin is desirable. 
     The free radical source suitable for use in the process are those materials typically used for polyolefin compounding and exhibiting free radical generation in the melt processing range typically used for polyolefins. Specific examples include 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane; t-butylperoctoate; t-butylperoxypivalate; dicumylperoxide; 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane; bis(t-butylperoxy-isopropyl)benzene and the like. 
     Blends of the reactive extruded polyolefin-PVOH compositions produced according to the present invention with PVOH, polyolefins or other polymers is also contemplated. Other polymers would include polystyrene, poly(ε-caprolactone), ABS, PVC, poly(methyl methacrylate), poly(vinylidene chloride), poly(vinylidene fluoride), styrene-maleic anhydride copolymers, poly(phenylene oxide)/polystyrene blends and the like. 
     Applications for the reactive extruded polyolefin-PVOH compositions produced according to the present invention include films, antistatic additives, injection molded articles, extruded profiles, fiber additives, foam and barrier containers. The reactive extruded compositions can be used as an adhesive interliner between films of polyolefins and PVOH. These compositions can be added to polyolefin or to PVOH, or to both, to improve the adhesion between layers of polyolefin and PVOH films. 
     REACTIVE MELT EXTRUSION PROCESS USED IN THE EXAMPLES 
     A twin screw extruder (Werner &amp; Pfleiderer ZSK-40 extruder) was set-up to conduct the Runs as discussed in the following Examples. The screw design was held constant and the feed ports for the constituents of the blends were kept constant. The polyolefin was fed to the extruder using conventional equipment designed to deliver constant flow rates. Maleic anhydride was melted and fed to the extruder as a liquid at a position where the polyolefin stream was fluxed. At a position further down the barrel of the extruder the peroxide was fed (as a liquid) optionally diluted with xylene. A mixing zone was utilized to assure mixing of the maleic anhydride and peroxide with the polyolefin and to allow for sufficient grafting to occur. After this reactive extrusion stage, the thermoplastic PVOH pellets were fed to an open throat of the extruder. A mixing zone was utilized to blend the grafted polyolefin with the thermoplastic PVOH followed by a vacuum port to remove unreacted maleic anhydride. The product was extruded through six dies onto a chilled belt and pelletized. 
     EXAMPLE 1 
     The first series of Runs 1-7 involved blends of a thermoplastic PVOH (Vinex 2025: Air Products and Chemicals, Inc.) with polypropylene (Profax 6723: Himont). The feed rates of the thermoplastic PVOH, polypropylene, L-101 peroxide [2,5-dimethyl-2,5-bis(t-butylperoxy)hexane], and maleic anhydride are noted in Table 1. The extrusion temperature settings were 200° C. across the extruder. The melt flow data in Table 1 were obtained at 200° C. using a procedure similar to ASTM-D1238. Samples of the Runs were injection molded at 200° C. into test specimens with properties obtained dry and after 25 days at 50% R. H. conditioning. The mechanical properties (tensile modulus, tensile strength, ultimate elongation) were determined using procedures similar to ASTM-D638. Note that 1P, 5P, and 10P refer to 44 psi (3.1 kg/cm 2 ), 220 psi (15.5 kg/cm 2 ), and 440 psi (31 kg/cm 2 ) loading applied to the melt index apparatus. The notched impact strength was determined using the procedure described by ASTM D-256. The mechanical properties are noted in Table 1. The major difference noted was the improved homogeneity of the injection molded surface with addition of both maleic anhydride and peroxide. Additionally, the ultimate elongation showed a distinct improvement with reactive modification using maleic anhydride and peroxide. 
     
                                           TABLE 1__________________________________________________________________________RUN    1       2       3       4       5       6       7__________________________________________________________________________Vinex 2025  40      40      40      40      40      40      40Feed Rate(lb/hr)Polypropy-  40      40      40      40      40      40      40leneFeed Rate(lb/hr)Maleic --      --      1.5%    1.5%    3.0%    --      0.75Anhydride*L-101  --      --      2300    4600    4600    4600    4600(peroxide)*Conc. (ppm)Vacuum No      Yes     Yes     Yes     Yes     Yes     YesMelt Flow  8.5(1P) 7.6(1P) 5.8(5P) 62.5(5P)                                  37.7(5P)                                          20.4(1P)                                                  14.8dg/min200° C.(1P)Mechanical  rough   rough   uniform uniform uniform rough   uniformProperties(Dry)MoldedSurfaceTensile  197,000 198,000 189,000 189,000 162,000 193,000 204,000Modulus (psi)Tensile  4,800   4,500   4,600   4,900   4,000   4,400   4,500Strength(psi)Elongation @  6       6       16      17      16      5       10Break (%)Notched Izod  1.0     1.1     0.84    1.1     1.0     0.9     0.82ImpactStrengthft. lbs./in.of notchMechanical Properties (50% RH: Conditioned for 25 days)Tensile  197,000  194,000                  174,000 185,000 176,000 168,000 175,000Modulus(psi)Tensile  4,230   4,140   4,210   4,680   4,590   3,960   4,190Strength(psi)Elongation @  6.0     5.0     14.0    21.3    17.6    6.3     8.8Break (%)Notched Izod  1.3     1.2     0.8     1.6     0.8     1.0     0.7ImpactStrengthft. lbs./in.of notch__________________________________________________________________________ 
    
     EXAMPLE 2 
     Runs 8-20 involved blends of Vinex 2025 thermoplastic PVOH and linear low density polyethylene (LLDPE) (Tuflin HS-7027: Union Carbide). The same extruder and extrusion conditions were employed as in Example 1 except for specific concentrations of the peroxide (L-101) and maleic anhydride. The specific Runs, and the property data of the resultant blends (controls and reactive extruded blends) are listed in Table 2. One blend (Run 20) utilized a 50/50 blend of LLDPE and polypropylene (Profax 6723) with Vinex 2025 PVOH. The property data were determined according to the procedures noted in Example 1. The addition of peroxide and/or maleic anhydride to the blends resulted in lower melt flow (higher melt viscosity). At higher levels of maleic anhydride and peroxide (Runs 11 and 12), the samples were too crosslinked to test. At the lower levels of maleic anhydride and peroxide, improved homogeneity of the blends was observed along with increased tensile strength and elongation at break compared to the control blend (Runs 8 and 9) as well as the blends with either peroxide or maleic anhydride addition (Runs 10 and 19). 
     
                                           TABLE 2__________________________________________________________________________RUN    8       9       10      11      12      13      14__________________________________________________________________________Vinex 2025  40      40      40      40      40      40      40Feed Rate(lb/hr)LLDPE  40      40      40      40      40      40      40Feed Rate(lb/hr)Maleic --      --      --      3.0     3.0     1.0     1.25Anhydride*Conc. (%)L-101                  2000    2000    1000    1000    1000(peroxide)*Conc. (ppm)Vacuum No      Yes     Yes     Yes     Yes     Yes     YesMelt Flow  12.6(1P)          12.0(1P)                  6.1(1P)                 No flowdg/min                                         (10P)14.4(10P)MechanicalProperties(Dry)Tensile  188,000 167,000 185,000 Too Cross-                                  Too Cross-                                          145,001 169,000Modulus (psi)                  linked to                                  linked toTensile  3,600   3,700   3,820   test    test    4,400   4,500Strength(psi)Elongation @  6       5       5                       7       28Break (%)Notched Izod  1.2     1.3     1.3                     1.2     1.3ImpactStrengthft. lbs./in.of notchMechanical Properties (50% RH: Conditioned for 25 days)Tensile  139,000 163,000 145,000                 126,000 122,000Modulus(psi)Tensile  2,950   3,094   3,239                   3,390   3,550Strength(psi)Elongation @  6.3     6.8     5.7                     7.3     38.8Break (%)Notched Izod  1.5     1.5     1.5                     1.5     2.2ImpactStrengthft. lbs./in.of notch__________________________________________________________________________   RUN    15      16      17      18      19      20__________________________________________________________________________   Vinex 2025          40      40      50      --      40      40   Feed Rate   (lb/hr)   LLDPE  40      40      50      40      40      40   Feed Rate   (lb/hr)   Maleic 0.5     0.5     0.5     0.5     0.5     1.0   Anhydride*   Conc. (%)   L-101  1000    500     500     500     --      1000   (peroxide)*   Conc. (ppm)   Vacuum Yes     Yes     Yes     Yes     Yes     Yes   Melt Flow          23.9(10P)                  14.4(10P)                          21.4(10P)                                  7.2(5P) 3.34(1P)   dg/min   1.88(10P)   Mechanical   Properties   (Dry)   Tensile          173,000 158,000 180,000 56,000  164,000 157,000   Modulus (psi)   Tensile          4,900   4,400   4,600   2,500   2,800   4,700   Strength   (psi)   Elongation @          9       7       6       939     4       6   Break (%)   Notched Izod          1.0     1.0     1.1     No      1.4     1.0   Impact                         break   Strength   ft. lbs./in.   of notchMechanical Properties (50% RH: Conditioned for 25 days)Tensile  139,000 134,000 127,000 58,000  143,000 139,000Modulus(psi)Tensile  3,980   3,645   3,660   2,610   2,350   4,015Strength(psi)Elongation @  18.5    11.1    10.0    978     6.0     6.3Break (%)Notched Izod  1.4     1.3     1.2     No      1.4     1.2Impact                         BreakStrengthft. lbs./in.of notch__________________________________________________________________________ *Based on LLDPE weight  50/50 blend of LLDPE/Profax 6723 PP 
    
     EXAMPLE 3 
     Runs 21-27 involved blends of Vinex 2025 thermoplastic PVOH and ethylene-propylene rubber (Vistalon 719 EPR: Exxon). Except for the specific concentrations of the peroxide (L-101) and maleic anhydride, the same extruder and extrusion conditions were employed as in Example 1. The specific experiments and the property data of the resultant blends (controls and reactive extruded blends) are listed in Table 3. The reactive extruded blends (Runs 23-25 and 27) yielded higher tensile strength, higher elongation at break, and much higher notched izod impact strength than the control blend (Run 21) or the control blend with peroxide addition (Run 22). Maleic anhydride addition alone (Run 26) gave higher tensile strength and elongation relative to the control blend and the control blend with peroxide but not as good overall as the blends with both maleic anhydride and peroxide addition. 
     
                                           TABLE 3__________________________________________________________________________RUN    21      22      23      24      25      26      27__________________________________________________________________________Vinex 2025  48      48      48      48      48      48      48Feed Rate(lb/hr)EPR    32      32      32      32      32      32      32Feed Rate(lb/hr)Maleic --      --      1.25    0.9     0.9     0.9     0.6Anhydride*Conc. (ppm)L-101  --      1000    1000    1000    600     --      600(peroxide)*Conc. (ppm)Vacuum Yes     Yes     Yes     Yes     Yes     Yes     YesMelt Flow  61.1(5P)          50.5(5P)                  No flow 0.95(10P)                                  1.27(10P)                                          1.18(10P)dg/min                 (10P)4.91(10P)MechanicalProperties(Dry)Tensile  117,000 124,000 153,000 143,000 164,000 151,000 139,000Modulus (psi)Tensile  3,500   3,200   5,200   5,300   5,400   5,500   5,100Strength(psi)Elongation @  9       7       81      78      73      16      88Break (%)Notched Izod  1.2     1.2     21.9    18.9    20.3    1.6     11.5ImpactStrengthft. lbs./in.of notchMechanical Properties (50% RH: Conditioned for 25 days)Tensile  82,000  88,000  72,000  73,000  82,000  86,000  68,000Modulus(psi)Tensile  2,015   1,925   2,995   2,900   3,015   3,500   2,860Strength(psi)Elongation @  15.7    13.6    179     184     156     79      222Break (%)Notched Izod  1.5     1.6     20.8    19.6    22.8    10.8    19.3ImpactStrengthft. lbs./in.of notch__________________________________________________________________________ *Based on EPR weight 
    
     EXAMPLE 4 
     Runs 28-31 involved blends of Vinex 2025 thermoplastic PVOH and a 75/25 blend of polypropylene (Profax 6723)/ethylene-propylene rubber (Vistalon 719). A thermoplastic PVOH/polyolefin blend ratio of 50/50  (by weight) was employed. Except for specific concentrations of the peroxide (L-101) and maleic anhydride, the same extruder and extrusion conditions were employed as noted in Example 1. The specific Runs and property data of the resultant blends (control and reactive extruded blends) are noted in Table 4. The data were obtained using the procedures noted in Example 1. The reactive extruded blends (Runs 28-30) exhibited significantly improved homogeneity over the blend control alone (Run 31) with increased tensile strength and ultimate elongation. 
     
                                           TABLE 4__________________________________________________________________________                                  Vinex   ProfaxRUN    28      29      30      31      2025    6723__________________________________________________________________________Vinex 2025  40      40      40      40      Control ControlFeed Rate(lb/hr)Polyolefin  40      40      40      40Feed Rate(lb/hr)Maleic 0.5     1.0     1.0     --Anhydride*Conc. (ppm)L-101  500     1000    2000    --(peroxide)*Conc. (ppm)Vacuum Yes     Yes     Yes     YesMelt Flow  12.0(10P)          1.44(10P)                  17.1(10P)                          6.3(1P) 55.2(5P)                                          83.2(10P)dg/minMechanicalProperties(Dry)Tensile  164,000 180,000 146,000 162,000 283,000 127,000Modulus (psi)Tensile  4,800   5,200   4,800   4,400   10,570  5,100Strength(psi)Elongation @  6       25      33      5       55      58Break (%)Notched Izod  0.83    1.23    1.50    1.1     0.69    2.2ImpactStrengthft. lbs./in.of notchMechanical Properties (50% RH: Conditioned for 25 days)Tensile  157,000 169,000 135,000 156,000 120,000 137,000Modulus(psi)Tensile  4,400   4,580   4,275   3,640   4,170   5,105Strength(psi)Elongation @  7.1     38.9    79.6    6.3     226     65.3Break (%)Notched Izod  1.1     1.9     2.8     1.6     38.1    2.2ImpactStrengthft. lbs./in.of notch__________________________________________________________________________ *Based on Polyolefin weight  75/25 Polypropylene/EPR 
    
     EXAMPLE 5 
     This Example compares a pregrafted polyolefin melt extruded with a thermoplastic PVOH (Run A) as taught in U.S. Pat. No. 4,600,746 (essentially a two pass operation) with the single pass, reactive extrusion process according to the present invention. 
     The maleic anhydride grafted polyethylene produced in Run 18 was recovered as pellets. The Run 18 pellets were blended with 50% by weight of thermoplastic PVOH (Vinex 2025) in a 1&#34; Killion extruder 30/1 L/D at 200° C. The resultant product (Run A) was injection molded into test specimens. The tensile properties of the Run A sample were significantly improved over the control samples (Runs 8 and 9). The Run A blend, however, was deeper in color (yellow) than either Runs 8 and 9 (control) or the reactive extrusion Runs. 
     Additionally, the Run A blend exhibited poor water resistance. Samples of Run A were placed in water at 23° C. along with samples of Run 9 (control) and Runs 13 and 16 (reactive extrusion). The sample of Run A became sticky on the surface when exposed to water, and water immersion (24 hours) resulted in sample disintegration. Samples of Runs 9, 13 and 16 did not exhibit the same degree of surface stickiness when exposed to water and did not disintegrate after 24 hour water immersion although they exhibited some swelling and surface softness. The improved water resistance is of significant benefit for certain barrier film applications. 
     EXAMPLE 6 
     A blend of 50% Vinex 2025 PVOH and 50% of the reactive extrusion blend of Run 23 (Vinex 2025/EPR: 60/40) was prepared in a 1&#34; Killion extruder at 200° C. The resultant pelletized blend was injection molded at 200° C. and mechanical properties were obtained on dry samples as noted in Table 5. 
     EXAMPLE 7 
     A blend of 50% Vinex 2025 PVOH and 50% of the reactive extrusion blend of Run 25 (Vinex 2025/EPR: 60/40) was prepared in a 1&#34; Killion extruder at 200° C. The resultant pelletized blend was injection molded at 200° C. and mechanical properties were obtained on dry samples as noted in Table 5. 
     EXAMPLE 8 
     A blend of 75% Vinex PVOH 2025 and 25% of the reactive extrusion blend of Run 25 (Vinex 2025/EPR: 60/40) was prepared in a 1&#34; Killion extruder at 200° C. The resultant pelletized blend was injection molded at 200° C. and mechanical properties were obtained on dry samples as noted in Table 5. 
     
                                           TABLE 5__________________________________________________________________________         Tensile           ImpactStrength      Modulus               Tensile                     %     ft. lbs/Example Composition         (psi) Strength                     Elongation                           in of notch__________________________________________________________________________6     50% Vinex 2025         282,000               8,986 40    4.1 50% Run 237     50% Vinex 2025         288,000               9,178 26    5.8 50% Run 258     75% Vinex 2025         315,000               11,375                     27    1.4 25% Run 25__________________________________________________________________________ 
    
     EXAMPLE 9 
     Blends of polypropylene (Profax 6723) and Vinex 2034 PVOH were extruded with variations in maleic anhydride and peroxide (L-101) addition. The data for Runs 41-49 are shown in Table 6. Runs 47-49 were at different Vinex/PP ratios. 
     
                                           TABLE 6__________________________________________________________________________RUN            41      42      43      44      45      46__________________________________________________________________________Vinex ™ Type          2034    2034    2034    2034    2034    2034Vinex Feed Rate (lbs/hr)          40      40      40      40      40      40Polyolefin Type          PP      PP      PP      PP      PP      PP          Profax  Profax  Profax  Profax  Profax  Profax          6723    6723    6723    6723    6723    6723Polyolefin Feed Rate (lbs/hr)          40      40      40      40      40      40Maleic Anhydride Conc. (%)*          --      --      2.2%    2.2%    3.2%    3.2%L-101 (peroxide) Conc. (ppm)*          --      --      3000    4000    4000    3000Melt Flow dg/min (200° C.)          10.2(1P)                  8.3(1P) 62.6(10P)                                  110(10P)                                          86.8(10P)Mechanical Properties (Dry)Tensile Modulus (psi)          110,000 110,000 124,000 124,000 137,000 140,000Tensile Strength (psi)          3,100   3,100   4,900   4,900   5,000   5,100Elongation @ Break (%)          16      17      105     126     91      101Notched Izod Impact Strength          1.1     1.5     0.78    0.77    0.82    0.78ft-lbs/in of notchMechanical Properties (50% RH: Conditioned for 25 days)Tensile Modulus (psi)          96,000  86,000  107,000 104,000 99,000  108,000Tensile Strength (psi)          3,000   2,800   4,200   4,200   4,200   4,200Elongation @ Break (%)          21      24      262     133     201     358Notched Izod Impact Strength          2.0     2.0     1.0     0.90    1.0     1.0ft-lbs/in of notch__________________________________________________________________________                   RUN            47      48      49__________________________________________________________________________                   Vinex ™ Type                                  2034    2034    2034                   Vinex Feed Rate (lbs/hr)                                  74      50      50                   Polyolefin Type                                  PP      PP      PP                                  Profax  Profax  Profax                                  6723    6723    6723                   Polyolefin Feed Rate (lbs/hr)                                  40      27      16                   Maleic Anhydride Conc. (%)*                                  2.2%    2.1%    3.5%                   L-101 (peroxide) Conc. (ppm)*                                  4000    4000    4000                   Melt Flow dg/min (200° C.)                                  44.9(10P)                                          10.0(10P)                                                  15.8(10P)                   Mechanical Properties (Dry)                   Tensile Modulus (psi)                                  110,000 126,000 124,000                   Tensile Strength (psi)                                  4,600   4,800   3,400                   Elongation @ Break (%)                                  75      11      9                   Notched Izod Impact Strength                                  0.81    0.68    0.89                   ft-lbs/in of notch                   Mechanical Properties (50% RH: Conditioned for 25                   days)                   Tensile Modulus (psi)                                  83,000  75,000  59,000                   Tensile Strength (psi)                                  3,800   3,700   2,400                   Elongation @ Break (%)                                  148     33      37                   Notched Izod Impact Strength                                  1.1     0.95    1.6                   ft-lbs/in of notch__________________________________________________________________________ *Based on polyolefin weight 
    
     EXAMPLE 10 
     Blends of polypropylene (Profax 8623}and Vinex 2034 were prepared via reactive extrusion. Profax 8623 PP is an impact grade polypropylene. The data for Runs 50-54 are shown in Table 7. 
     
                                           TABLE 7__________________________________________________________________________RUN            50      51      52      53      54__________________________________________________________________________Vinex ™ Type          2034    2034    2034    2034    2034Vinex Feed Rate (lbs/hr)          40      40      40      40      40Polyolefin Type          PP      PP      PP      PP      PP          Profax  Profax  Profax  Profax  Profax          8623    8623    8623    8623    8623Polyolefin Feed Rate (lbs/hr)          40      40      40      40      40Maleic Anhydride Conc. (%)*          --      2.0%    3.5%    2.1%    3.1%L-101 (peroxide) Conc. (ppm)*          --      4000    3000    3000    4000Melt Flow dg/min (200° C.)          7.9(1P) 102.2(10P)                          27.5(10P)                                  59.0(10P)                                          28.1(10P)Mechanical Properties (Dry)Tensile Modulus (psi)          111,000 111,000 109,000 114,000 113,000Tensile Strength (psi)          3,400   3,900   4,000   4,000   3,900Elongation @ Break (%)          16      153     104     87      124Notched Izod Impact Strength          1.9     1.1     1.1     1.2     1.1ft-lbs/in of notchMechanical Properties (50% RH: Conditioned for 25 days)Tensile Modulus (psi)          72,000  85,000  77,000  64,000  75,000Tensile Strength (psi)          2,800   3,800   3,200   3,200   3,300Elongation @ Break (%)          37      494     325     280     349Notched Izod Impact Strength          2.7     1.7     2.1     2.0     2.0ft-lbs/in of notch__________________________________________________________________________ *Based on polyolefin weight 
    
     EXAMPLE 11 
     Blends of polypropylene (Profax 8623) and Vinex 2025 PVOH were prepared for comparison with similar blends employing Vinex 2034 PVOH. The data for Runs 55-57 are shown in Table 8. Vinex 2034 PVOH yielded much higher ultimate elongation with Profax 8623 PP than similar blends with Vinex 2025 PVOH. Reactive extrusion yielded significant improvements for both blends. 
     
                                           TABLE 8__________________________________________________________________________Run                55   56   57   58__________________________________________________________________________Vinex ™ Type    2025 2025 2025 2025Vinex Feed Rate (lbs/hr)              40   40   40   40Polyolefin Type    PP   PP   PP   PP              Profax                   Profax                        Profax                             Profax              8623 8623 8623 6723Polyolefin Feed Rate (lbs/hr)              40   40   40   40Maleic Anhydride Conc. (%)*              3.1% 2.0%  --  2.1%L-101 (peroxide) Conc. (ppm)*              4000 3000  --  3000Melt flow dg/min (200° C.)              28.4(10P)                   2.5(1P)                        11.7(1P)                             3.2(1P)Mechanical Properties (Dry)Tensile Modulus (psi)              158,000                   168,000                        179,000                             179,000Tensile Strength (psi)              4,100                   4,100                        4,500                             5,100Elongation @ Break (%)              34   18   5    19Notched Izod Impact Strength              1.3  1.1  1.3  0.84ft-lbs/in of notchMechanical Properties(50% R.H. Conditioning for 25 days)Tensile Modulus (psi)              112,000                   116,000                        135,000                             151,000Tensile Strength (psi)              3,600                   3,600                        4,000                             4,700Elongation @ Break (%)              45   29   11   34Notched Izod Impact Strength              1.6  1.1  1.5  0.70ft-lbs/in of notch__________________________________________________________________________ *Based on polyolefin weight 
    
     EXAMPLE 12 
     A 50/50 blend of Vinex 2025 PVOH/Profax 6723 PP (Run 58 of Table 8) was made for comparison with Vinex 2034 PVOH/Profax 6723 PP reactive extruded blends. Vinex 2034 PVOH offered significantly higher ultimate elongation. 
     EXAMPLE 13 
     50/50 blends of Vinex 2025/LLDPE (LL-1002; Exxon Chemical) were prepared and subjected to reactive extrusion conditions. The data for Runs 59-62 are shown in Table 9. Polyethylene led to crosslinking with peroxide addition unlike polypropylene for which chain scission dominated resulting in high melt viscosity. Consequently, much lower levels of maleic anhydride and peroxide were employed. The addition of maleic anhydride and peroxide led to significant improvements in ultimate elongation, tensile strength and notched toughness except for Run 62 which appeared anomalous. 
     
                                           TABLE 9__________________________________________________________________________Run                59   60   61   62__________________________________________________________________________Vinex ™ Type    2025 2025 2025 2025Vinex Feed Rate (lbs/hr)              40   40   40   40Polyolefin Type    LLDPE                   LLDPE                        LLDPE                             LLDPE              LL-1002                   LL-1002                        LL-1002                             LL-1002Polyolefin Feed Rate (lbs/hr)              40   40   40   40Maleic Anhydride Conc. (%)*              0.5% 0.5%  --  0.62%L-101 (peroxide) Conc. (ppm)*              600  400   --  ˜400Melt flow dg/min (200° C.)              0.9(10P)                   2.3(10P)                        11.5(1P)                             1.4(10P)Mechanical Properties (Dry)Tensile Modulus (psi)              135,000                   132,000                        124,000                             120,000Tensile Strength (psi)              4,300                   4,600                        3,200                             3,700Elongation @ Break (%)              85   52   7    7Notched Izod Impact Strength              3.4  1.9  1.3  1.2ft-lbs/in of notchMechanical Properties(50% R.H. Conditioning for 25 days)Tensile Modulus (psi)              52,000                   62,000                        75,000                             74,000Tensile Strength (psi)              3,200                   3,100                        2,300                             2,600Elongation @ Break (%)              171  120  30   12Notched Izod Impact Strength              N.B.**                   11.8 2.1  1.4ft-lbs/in of notch__________________________________________________________________________ *Based on polyolefin weight **N.B. = No Break 
    
     EXAMPLE 14 
     Runs 63-66 were 50/50 blends of Vinex 2034 PVOH and LLDPE (HS-7027) which offered significant improvements in ultimate elongation and tensile strength with maleic anhydride and peroxide addition as shown in Table 10. 
     
                                           TABLE 10__________________________________________________________________________Run               63   64   65   66   67   68__________________________________________________________________________Vinex ™ Type   2034 2034 2034 2034 2034 2034Vinex Feed Rate (lbs/hr)             40   40   40   40   60   60Polyolefin Type   LLDPE                  LLDPE                       LLDPE                            LLDPE                                 PP 6723/                                      PP6723/             HS-7027                  HS-7027                       HS-7027                            HS-7027                                 EPR-719                                      EPR-719Polyolefin Feed Rate (lbs/hr)             40   40   40   40   30/10                                      30/10Maleic Anhydride Conc. (%)*             0.75%                  0.75%                       0.5%  --  2.2% 2.4%L-101 (peroxide) Conc. (ppm)*             400  600  600   --  1900 1900Melt flow dg/min (200° C.)             2.3(10P)                  2.3(10P)                       10.6(10P)                            9.2(10P)                                 10.6(10P)2.9(10P)Mechanical Properties (Dry)Tensile Modulus (psi)             87,000                  87,000                       87,000                            77,000                                 108,000                                      109,000Tensile Strength (psi)             3,600                  3,800                       3,500                            2,700                                 4,200                                      4,300Elongation @ Break (%)             25   147  100  23   73   55Notched Izod Impact Strength             1.2  2.6  1.4  1.5  1.4  1.3ft-lbs/in of notchMechanical Properties(50% R.H. Conditioning for 25 days)Tensile Modulus (psi)             52,000                  40,000                       47,000                            48,000                                 61,000                                      75,000Tensile Strength (psi)             2,900                  3,100                       2,800                            2,300                                 3,400                                      3,500Elongation @ Break (%)             53   235  135  41   99   79Notched Izod Impact Strength             2.2  N.B.**                       6.6  2.0  3.5  2.6ft-lbs/in of notch__________________________________________________________________________ *Based on polyolefin weight **No break 
    
     EXAMPLE 15 
     Runs 67 and 68 involved a 60/30/10 blend of Vinex 2034/Profax 6723/EPR-719. See Table 10 for data. 
     EXAMPLE 16 
     Surlyn 9020/Vinex PVOH blends without reactive extrusion exhibit reasonable mechanical compatibility. Runs 69-76 were conducted with reactive extrusion processing. As shown in Table 11, modest improvements in tensile strength were observed with reactive processing. However, lower ultimate elongation was observed. In this case, reactive extrusion is not necessary and not desired except where improved water resistance may be required as exemplified in Example 5. 
     EXAMPLE 17 
     Vinex 2025/Surlyn 8660 blends (Runs 77 and 78) were prepared via reactive extrusion and no advantage of reactive processing versus the control (Run 79) is clear from Table 11 other than where improved water resistance is required as exemplified in Example 5. 
     
                                           TABLE 11__________________________________________________________________________Run               69   70   71   72   73   74__________________________________________________________________________Vinex ™ Type   2025 2025 2025 2025 2025 2025Vinex Feed Rate (lbs/hr)             40   40   40   40   40   40Polyolefin Type   Surlyn                  Surlyn                       Surlyn                            Surlyn                                 Surlyn                                      Surlyn             9020 9020 9020 9020 9020 9020Polyolefin Feed Rate (lbs/hr)             40   40   40   40   40   40Maleic Anhydride Conc. (%)*              --   --  0.4% 0.4% 0.6% 0.6%L-101 (peroxide) Conc. (ppm)*             --   400  400  600  600   --Melt flow dg/min (200° C.)             80.0(5P)                  58.8(5P)                       30.2(5P)                            11.2(5P)                                 10.8(5P)                                      9.8(5P)Mechanical Properties (Dry)Tensile Modulus (psi)             63,000                  138,000                       134,000                            130,000                                 145,000                                      123,000Tensile Strength (psi)             3,500                  4,800                       4,800                            4,800                                 5,100                                      5,000Elongation @ Break (%)             291  114  174  147  78   24Notched Izod Impact Strength             3.4  1.7  2.5  1.9  2.3  1.9ft-lbs/in of notchMechanical Properties(50% R.H. Conditioning for 25 days)Tensile Modulus (psi)             28,000                  84,000                       83,000                            83,000                                 92,000                                      39,000Tensile Strength (psi)             3,350                  3,900                       3,700                            3,700                                 3,700                                      3,300Elongation @ Break (%)             403  281  246  202  131  257Notched Izod Impact Strength             8.2  4.1  3.4  4.1  3.7  3.2ft-lbs/in of notch__________________________________________________________________________Run               75   76   77   78   79__________________________________________________________________________Vinex ™ Type   2025 2034 2025 2025 2025Vinex Feed Rate (lbs/hr)             40   40   40   40   40Polyolefin Type   Surlyn                  Surlyn                       Surlyn                            Surlyn                                 Surlyn             9020 9020 8660 8660 8660Polyolefin Feed Rate (lbs/hr)             40   40   40   40   40Maleic Anhydride Conc. (%)*             0.5% 0.5% 0.75%                            1.0%  --L-101 (peroxide) Conc. (ppm)*             500  500  500  1000  --Melt flow dg/min (200° C.)             16.3(5P)                  10.4(5P)                       26.8(1P)                            22.0(1P)                                 32.2(1P)Mechanical Properties (Dry)Tensile Modulus (psi)             140,000                  80,000                       141,000                            83,000                                 160,000Tensile Strength (psi)             5,100                  3,900                       5,200                            2,950                                 5,400Elongation @ Break (%)             89   171  54   16   87Notched Izod Impact Strength             2.9  3.4  0.92 0.64 0.76ft-lbs/in of notchMechanical Properties(50% R.H. Conditioning for 25 days)Tensile Modulus (psi)             83,000                  73,000                       92,000                            59,000                                 126,000Tensile Strength (psi)             4,100                  3,500                       3,800                            2,300                                 4,400Elongation @ Break (%)             202  94   343  23   248Notched Izod Impact Strength             6.3  8.9  1.1  0.85 1.1ft-lbs/in of notch__________________________________________________________________________ *Based on polyolefin weight 
    
     EXAMPLE 18 
     Blends of 50/50 Vinex 2025/Primacor 5981 (high melt flow EAA - 20 wt % AA) were prepared as Runs 80 and 81. Reactive extrusion (Run 81) improved the strength, elongation and toughness. A different ratio Vinex 2025/Primacor 5981 (54/36) in control Run 82 was prepared to determine if a high melt flow product would be obtained. 
     A control Run 83 and a reactive extruded blend of Primacor 1430/Vinex 2025 (50/50) (Run 84) were prepared. Primacor 1430 EAA is a high molecular ethylene-acrylic acid copolymer (˜8 wt % AA; Dow Chemical Co.) that offers fair mechanical compatibility with Vinex PVOH. The data for Runs 80-84 are shown in Table 12. Reactive extrusion only shows an improvement in notched toughness with decreases in elongation and tensile strength. 
     
                                           TABLE 12__________________________________________________________________________Run               80   81   82   83   84__________________________________________________________________________Vinex ™ Type   2025 2025 2025 2025 2025Vinex Feed Rate (lbs/hr)             40   40   54   40   40Polyolefin Type   Primacor                  Primacor                       Primacor                            Primacor                                 Primacor             5981 5981 5981 1430 1430Polyolefin Feed Rate (lbs/hr)             40   40   36   40   40Maleic Anhydride Conc. (%)*              --  0.5%  --   --  0.5%L-101 (peroxide) Conc. (ppm)*              --  500   --   --  500Melt flow dg/min (200° C.)             17.0(1P)                  7.3(1P)                       3.4(1P)                            5.4(1P)                                 3.0(5P)Mechanical Properties (Dry)Tensile Modulus (psi)             37,000                  36,000                       45,000                            141,000                                 109,000Tensile Strength (psi)             1,700                  2,000                       2,400                            4,700                                 4,000Elongation @ Break (%)             20   71   39   100  61Notched Izod Impact Strength             0.53 0.89 0.80 0.80 1.5ft-lbs/in of notchMechanical Properties(50% R.H. Conditioning for 25 days)Tensile Modulus (psi)             33,000                  36,000                       43,000                            102,000                                 87,000Tensile Strength (psi)             1,500                  2,200                       2,600                            3,800                                 3,600Elongation @ Break (%)             20   64   47   306  134Notched Izod Impact Strength             0.59 0.77 0.68 1.3  2.2ft-lbs/in of notch__________________________________________________________________________ *Based on polyolefin weight 
    
     EXAMPLE 19 
     Runs 85-88 were performed to determine if the reactive extrusion procedure was applicable to ethylene/vinyl alcohol copolymers (e.g. EVAL EP-F). The results in Table 13 show only a modest increase in elongation and thus indicates that reactive extrusion is of more benefit to PVOH. 
     EXAMPLE 20 
     Blends of Vinex 2025 PVOH and an ethylene-vinyl acetate copolymer (LD-706; Exxon Chemical) were prepared as Runs 89-92 of Table 13. Definite improvements in tensile strength, ultimate elongation and notched toughness were observed with reactive extrusion. 
     EXAMPLE 21 
     Blends of Vinex 2025 PVOH and Vistalon ethylene-propylene rubber (EPR 3708; Exxon Chemical) were prepared (Runs 93-96). Significant improvements were observed in ultimate elongation, tensile strength and notched toughness at the higher maleic anhydride/peroxide levels as shown in Table 13. 
     EXAMPLE 22 
     Run 97 involved the normal addition of Vinex 2034 PVOH after addition of maleic anhydride and peroxide to the polypropylene. Run 98 involved addition of both Vinex 2034 PVOH and polypropylene to the front of the extruder followed by maleic anhydride and peroxide addition. The results in Table 13 clearly show that this procedure is not desired for the conditions of this experiment. The maleic anhydride probably crosslinks the PVOH, the peroxide degrades the polypropylene and minimal grafting occurs. However, low maleic anhydride levels with ethylene-based polyolefins may be of interest using this approach. 
     
                                           TABLE 13__________________________________________________________________________Run            85     86     87     88     89   90__________________________________________________________________________Vinex ™ Type          EVAL EP-F                 EVAL EP-F                        EVAL EP-F                               EVAL EP-F                                      2025 2025Vinex Feed Rate (lbs/hr)          40     40     40     40     40   40Polyolefin Type          PP     PP     PP     PP 6723/                                      LD-706                                           LD-706          Profax Profax Profax EPR-719                                      EVA  EVA          6723   6723   6723Polyolefin Feed Rate (lbs/hr)          40     40     40     30/10  40   40Maleic Anhydride Conc. (%)*           --     --    1.0%   1.0%    --  0.5%L-101 (peroxide) Conc. (ppm)*           --    1500   1500   1500    --  500Melt flow dg/min (200° C.)          4.5(1P)                 17.6(1P)                        9.7(1P)                               3.9(5P)                                      18.2(1P)Mechanical Properties (Dry)Tensile Modulus (psi)          190,000                 185,000                        168,000                               129,000                                      96,000                                           67,000Tensile Strength (psi)          5,600  4,800  4,700  3,300  2,300                                           2,700Elongation @ Break (%)          6      7      10     12     8    51Notched Izod Impact Strength          1.2    0.85   0.73   1.0    1.3  3.5ft-lbs/in of notchMechanical Properties(50% R.H. Conditioningfor 25 days)Tensile Modulus (psi)          183,000                 190,000                        182,000                               144,000                                      38,000                                           37,000Tensile Strength (psi)          5,600  5,000  5,200  3,500  1,900                                           2,300Elongation @ Break (%)          6      6      12     13     31   198Notched Izod Impact Strength          1.1    0.66   0.59   0.92   1.9  7.7ft-lbs/in of notch__________________________________________________________________________Run            91     92     93     94     95   96   97   98__________________________________________________________________________Vinex ™ Type          2025   2025   2025   2025   2025 2025 2034 2034.sup.#Vinex Feed Rate (lbs/hr)          40     40     54     54     54   54   60   60Polyolefin Type          EVA    EVA    EPR    EPR    EPR  EPR  PP   PP          LD-706 LD-706 3708   3708   3708 3708 Profax                                                     Profax                                                6723 6723Polyolefin Feed Rate (lbs/hr)          40     40     36     36     36   36   40   40Maleic Anhydride Conc. (%)*          0.8%   1.0%    --    0.4%   0.9% 1.0% 2.2% 1.0%L-101 (peroxide) Conc. (ppm)*          800    1200    --    400    900  1200 3000 2000Melt flow dg/min (200° C.)          5.2(10P)                 3.9(10P)                        2.1(1P)                               1.9(1P)                                      2.4(10P)  36.0(5P)                                                     4.7(1P)2.5(10P)Mechanical Properties (Dry)Tensile Modulus (psi)          88,000 124,000                        138,0000                               137,000                                      112,000                                           137,000                                                109,000                                                     124,000Tensile Strength (psi)          3,100  3,700  3,300  3,400  3,800                                           4,400                                                4,800                                                     2,400Elongation @ Break (%)          60     61     5      6      129  129  48   7Notched Izod Impact Strength          3.1    7.9    1.2    0.94   20.1 21.1 0.86 0.77ft-lbs/in of notchMechanical Properties(50% R.H. Conditioningfor 25 days)Tensile Modulus (psi)          37,000 43,000 70,000 70,000 36,000                                           63,000                                                78,000                                                     86,000Tensile Strength (psi)          2,500  2,600  2,100  2,100  2,700                                           3,000                                                3,900                                                     2,100Elongation @ Break (%)          216    170    13     21     388  373  333  12Notched Izod Impact Strength          N.B.** N.B.** 1.7    1.8    N.B.**                                           N.B.**                                                1.4  0.96ft-lbs/in of notch__________________________________________________________________________ *Based on polyolefin weight **N.B. = No Break .sup.# Vinex 2025 fed to barrel 1 
    
     STATEMENT OF INDUSTRIAL APPLICATION 
     The present invention provides a process for the reactive melt extrusion grafting of polyolefin/thermoplastic PVOH blends which are suitably used in barrier films, foam, injection molded articles and extrusion applications.