Patent Publication Number: US-2003229946-A1

Title: Polymeric surfactant compositions and methods of manufacture and use

Description:
FIELD OF THE INVENTION  
       [0001] The present invention relates to polymeric surfactants. More specifically, the invention relates to polyhydroxystearic acid and polyethylene glycol polymeric compositions and methods of use to provide durable wicking finishes to textile fibers or fabrics.  
       BACKGROUND OF RELATED TECHNOLOGY  
       [0002] Synthetic fibers, such as polyester, polypropylene and polyethylene fibers, are generally considered to be hydrophobic. Applications exist, however, for which such hydrophobic characteristics are undesirable. For example, synthetic fibers are commonly used as a liner or cover stock in baby diapers, feminine hygiene products, adult incontinence products, and the like. Such cover stocks are typically next to the wearer&#39;s skin and are often nonwoven to provide passageways for liquids to travel therethrough. In these applications it is often desirable to have moisture pass through the synthetic fiber cover stock into an absorbent layer for collecting the moisture. A hydrophobic fiber, however, tends to repel the moisture resulting in liquid running off the cover stock as contrasted to permitting the passage of the liquid through the cover stock and into the absorbent layer.  
       [0003] Surfactant compositions have been used to counteract the hydrophobicity of nonwoven, synthetic fibers. For example, polyoxyethylene monolaurate has been used in nonwoven polypropylene cover stock applications. Such surfactant compositions, however, are typically not durable in high moisture or aqueous environments and tend to wash off the fabric with the aqueous fluid, thereby removing the surfactant composition.  
       [0004] As such there is a need in the art for a more durable surfactant composition suitable for use with nonwoven, synthetic fiber cover stocks for diapers, feminine hygiene products, adult incontinence products, and the like  
       SUMMARY OF THE INVENTION  
       [0005] The present invention is a polymeric surfactant composition for use as a wicking agent on a textile fiber or fabric. The polymeric surfactants of the present invention are durable, i.e., they do not wash off the textile after repeated contact with aqueous fluids.  
       [0006] In one aspect of the present invention, A-B block polymeric surfactant compositions comprise compounds that are a reaction product of polyhydroxycarboxylic acid having a molecular weight from about 600 daltons to about 2,100 daltons and an end-capped polyoxyalkylene glycol having a molecular weight from about 750 daltons to about 5,000 daltons.  
       [0007] In another aspect of the present invention, A-B-A polymeric surfactant compositions are provided for treating textile fibers and fabrics. The A-B-A block polymeric surfactant compositions comprise compounds that are a reaction product of polyhydroxycarboxylic acids having a molecular weight from about 600 daltons to about 2,100 daltons, defining the A portion of the polymer, and polyalkylethylene glycols having a molecular weight from about 200 daltons to about 3,200 daltons, defining the B portion of the polymer.  
       [0008] The polymeric blocks formed from the end-capped polyalkylethylene glycols or polyoxyalkylene glycols are hydrophilic. The polymeric blocks formed from the polyhydroxycarboxylic acids are hydrophobic in nature. A balance of the hydrophilic and hydrophobic blocks are provided to, among other things, provide a durable textile wicking finish to a synthetic textile fiber or fabric. Furthermore, the block polymeric surfactants of the present invention provide lubricity to the textile fiber. A textile fiber with such lubricity is useful for manufacturing of the fiber into a textile pattern, such as a nonwoven textile pattern, as the fiber is processed through textile machinery.  
       [0009] In another aspect of the present invention, the A-B block polymeric surfactant compositions are polymers comprising compounds of the following formula:  
                 
 
       [0010] wherein R is hydrogen or a substituted or unsubstituted hydrocarbon group, a is from about 2 to about 8, b is from about 8 to about 14, a+b is from about 10 to about 22, n is an integer from about 2 to about 10, R 1  is hydrogen or a C 1  to C 6  alkyl, R 2  is a C 1  to C 6  alkyl, and x is an integer from about 5 to about 90.  
       [0011] In yet another aspect of the present invention, the A-B-A block polymeric surfactant compositions are polymers comprising compounds of the following formula:  
                 
 
       [0012] wherein R or R″, which can be the same or different, is hydrogen or a substituted or unsubstituted hydrocarbon group, c or c″, which can be the same or different, is from about 2 to about 8, d or d″, which can be the same or different, is from about 8 to about 14, c+d or c″+d″, which can be the same or different, is from about 10 to about 22, m or m″, which can be the same or different, is an integer from about 1 to about 10, R 1  is hydrogen or a C 1  to C 6  alkyl, and y is an integer from about 10 to about 150.  
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0013]FIG. 1 is a schematic of a portion of an article having a textile layer.  
     [0014]FIG. 2 is a cross-sectional view of the article of FIG. 1.  
     [0015]FIG. 3 is a depiction of a textile fiber contained within the textile layer of FIG. 1.  
     [0016]FIG. 4 is a depiction of the textile fiber of FIG. 3 having a surfactant composition externally coating the fiber. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0017] The surfactant compositions of the present invention are block copolymeric surfactant compositions useful for fabric finishing. The surfactant compositions of the present invention may be used to treat synthetic fibers or textiles to provide a degree of hydrophilicty or wettability for imparting a wicking effect thereat. As used herein, wicking and its variants refer to the capillarity of a material partially immersed or otherwise in contact with an aqueous fluid. The surfactant compositions of the present invention comprise alternating hydrophobic and hydrophilic polymeric blocks. The size and type of these alternating polymeric blocks are selected to provide, among other things, a wicking effect or capillarity on the synthetic fiber to textile treated with the inventive surfactant compositions. The surfactant compositions also have enhanced durability as compared to previously known fiber finishing compositions.  
     [0018] The surfactant composition of the present invention are block polymers of polyesters of polyhydroxycarboxylic acids and polyoxyalkylene glycols. Desirably, the polyhydroxycarboxylic acids are polyhydroxystearic (PHS) acids to provide polyhydroxy stearate blocks. Useful polyoxyalkylene glycols include polyethylene glycols (PEG) and methoxy polyethylene glycols (mPEG). The use of methoxy polyethylene glycols provides end-capped polymeric surfactant compositions.  
     [0019] In one aspect of the present invention, the A-B block polymeric surfactant compositions are a reaction product of a polyhydroxycarboxylic acid, which defines the A block, having a molecular weight from about 600 daltons to about 2,100 daltons and an end-capped polyoxyalkylene glycol, which defines the B block, having a molecular weight from about 300 daltons to about 5,000 daltons. The polyhydroxycarboxylic acid comprises compounds that are a reaction product of monocarboxylic acid having the following formula:  
     R 3 —COOH,  
     [0020] where R 3  is C 1  to C 20  hydrocarbon group, and a hydroxycarboxylic acid of the following formula:  
                 
 
     [0021] where R 4  is hydrogen or a C 1  to C 12  hydrocarbon group and z is from 0 to about 12. Useful monocarboxylic acids include acetic acid, propionic acid, caproic acid, stearic acid, or combinations thereof. Useful hydroxycarboxylic acids include glycolic acid, lactic acid, hydracrylic acid, 12-hydroxystearic acid, or combinations thereof. Desirably, the polyhydroxycarboxylic acid is a polyhydroxystearic (PHS) acid formed from the reaction of stearic acid, where R 3  is CH 3 (CH 2 ) 5 CH 2 (CH 2 ) 10 , and 12-hydroxystearic acid, where R 4  is CH 3 (CH 2 ) 5  and z is 10.  
     [0022] Desirably, the average molecular weight of the polyhydroxycarboxylic acid component is from about 600 daltons to about 2,100 daltons. More desirably, the average molecular weight of the polyhydroxycarboxylic acid component is from about 1,300 daltons to about 1,700 daltons. Moreover, an average molecular weight from about 1,450 daltons to about 1,550 daltons of the polyhydroxycarboxylic acid component is also desirable. Furthermore, an average molecular weight of about 1,500 daltons is also useful for the polyhydroxycarboxylic acid component of the present invention.  
     [0023] The end-capped polyalkylethylene glycol comprises compounds of the following formula:  
                 
 
     [0024] where R 1  is hydrogen or a C 1  to C 6  alkyl, R 2  is a C 1  to C 6  alkyl, and x is an integer from about 5 to about 90.  
     [0025] Desirably, the average molecular weight of the end-capped polyoxyalkylene glycol is from about 300 daltons to about 5,000 daltons, or where x is from about 6 to about 83. More desirably, the average molecular weight of the end-capped polyoxyalkylene glycol is from about 300 daltons to about 1,000 daltons, or where x is from about 6 to about 16. An average molecular weight of about 350 daltons to about 750 daltons or an x of about 7 to 12 is also useful for the end-capped polyoxyalkylene glycol.  
     [0026] Moreover, the use of a methoxy polyethylene glycol (MPEG) as the end-capped polyalkylethylene glycol, where R 1  is hydrogen and R 2  is methyl in the above-described formula, is also useful with the practice of the present invention. The above described ranges of molecular weights and stoichiometries for the end-capped polyalkylethylene glycols may suitably be used for the methoxy polyethylene glycols.  
     [0027] In another aspect of the present invention, a polymeric surfactant comprising an A-B block polymer is provided. The A component of the block polymer is defined by the above-described polyhydroxycarboxylic acids, and the B component of the block polymer is defined by the above-described end-capped polyoxyalkylene glycols. The A-B block polymer comprises compounds of the following formula:  
                 
 
     [0028] wherein R is hydrogen or a substituted or unsubstituted hydrocarbon group, a is from about 2 to about 8, b is from about 8 to about 14, a+b is from about 10 to about 22, n is an integer from about 2 to about 10, R 1  is hydrogen or a C 1  to C 6  alkyl, R 2  is a C 1  to C 6  alkyl, and x is an integer from about 5 to about 90. Desirably, R is a fatty acid. More desirably, R is a C 12  to C 18  fatty acid. Desirably, x is from about 4 to 8. More desirably, x is from about 5 to 7. An x of about 6 is also useful.  
     [0029] In the A-B block polymeric composition, an average molecular weight of the polyhydroxycarboxylic acid component from about 600 daltons to about 2,100 daltons is useful with the practice of the present invention. Desirably, the average molecular weight of the polyhydroxycarboxylic acid component is from about 1,300 daltons to about 1,700 daltons. More desirably, the average molecular weight of the polyhydroxycarboxylic acid component is from about 1,450 daltons to about 1,550 daltons. An average molecular weight of about 1,500 daltons is also useful for the polyhydroxycarboxylic acid component of the present invention. Moreover, the use of polyhydroxystearic acid, i.e., a poly (12-hydroxystearic acid) chain terminated with stearic acid, as the polyhydroxycarboxylic acid is also desirable. In such as case, a equals 5, b equals 10 and R is CH 3 —(CH 2 ) 5 —CHOH—(CH 2 ) 10 —C═O.  
     [0030] Desirably, in the A-B block polymeric compositions the average molecular weight of the end-capped polyoxyalkylene glycol is from about 300 daltons to about 5,000 daltons, or where x is from about 6 to about 83. More desirably, the average molecular weight of the end-capped polyoxyalkylene glycol is from about 300 daltons to about 1,000 daltons, or where x is from about 6 to about 16. An average molecular weight of about 350 daltons to about 750 daltons or an x of about 7 to 12 is also useful for the end-capped polyoxyalkylene glycol. Moreover, the use of a methoxy polyethylene glycol (MPEG) as the end-capped polyalkylethylene glycol, where R 1  is hydrogen and R 2  is methyl in the above-described formula, is also useful with the practice of the present invention. The above described ranges of molecular weights and stoichiometries for the end-capped polyalkylethylene glycols may suitably be used for the methoxy polyethylene glycols.  
     [0031] A-B-A polymeric surfactant compositions are also useful with the practice of the present invention for treating textile fibers and fabrics. Useful textile finishing compositions comprise A-B-A block polymeric surfactant compositions that are a reaction product of polyhydroxycarboxylic acids having a molecular weight from about 600 daltons to about 2,100 daltons, defining the A portions of the polymer, and polyalkylethylene glycols having a molecular weight from about 200 daltons to about 3,200 daltons, defining the B portion of the polymer. The polyhydroxycarboxylic acids for the A-B-A polymeric surfactant compositions of the present invention comprise compounds of the following formula:  
                 
 
     [0032] wherein R is hydrogen or a substituted or unsubstituted hydrocarbon group, c is from about 2 to about 8, d is from about 8 to about 14, c+d is from about 10 to about 22 and m is an integer from about 1 to about 10. The polyhydroxycarboxylic acids are reaction products of the above-described hydroxycarboxylic acids and monocarboxylic acids.  
     [0033] The polyalkylethylene glycols for the A-B-A polymeric surfactant compositions of the present invention comprise compounds of the following formula:  
                 
 
     [0034] wherein R 1  is hydrogen or C 1  to C 6  alkyl and y is an integer from about 2 to about 100.  
     [0035] The A-B-A block polymer comprise compounds of the following formula:  
                 
 
     [0036] wherein R or R″, which can be the same or different, is hydrogen or a substituted or unsubstituted hydrocarbon group, c or c″, which can be the same or different, is from about 2 to about 8, d or d″, which can be the same or different, is from about 8 to about 14, c+d or c″+d″, which can be the same or different, is from about 10 to about 22, m or m″, which can be the same or different, is an integer from about 1 to about 10, R 1  is hydrogen or a C 1  to C 6  alkyl, and y is an integer from about 2 to about 100.  
     [0037] Desirably, the average molecular weight of each of the polyhydroxycarboxylic acid components are from about 1,000 daltons to about 2,000 daltons, or where m or m″ is from about 4 to about 8. More desirably, the average molecular weight of each of the polyhydroxycarboxylic acid components are from about 1,250 daltons to about 1,750 daltons, or where m or m″ is from about 5 to about 7. An average molecular weight of about 1,500 daltons or an average m or m″ of about 6 is also useful for the polyhydroxycarboxylic acid component of the present invention.  
     [0038] Moreover, the use of a polyhydroxystearic (PHS) acid as the polyhydroxycarboxylic acid for the A component is also desirable. When the polyhydroxycarboxylic acid is a polyhydroxy stearic acid, c and c″ equal 5, d and d″ equal 10, and R and R″ are CH 3 —(CH 2 ) 5 —CHOH—(CH 2 ) 10 —C=0 in the above-described formula. The above-described ranges of molecular weights and stoichiometries for the polyhydroxycarboxylic acids may suitably be used for the polyhydroxystearic acids.  
     [0039] Desirably, the average molecular weight of the polyoxyalkylene glycol, which defines the B block, in the A-B-A block polymeric composition is from about 200 daltons to about 3,200 daltons, or where y is from about 5 to about 73. More desirably, the average molecular weight of the polyoxyalkylene glycol is from about 200 daltons to about 2,000 daltons, or where y is from about 5 to about 45. An average molecular weight of about 600 daltons to about 1,500 daltons or a y of about 14 to 34 is also useful for the end-capped polyoxyalkylene glycol.  
     [0040] Moreover, the use of a polyethylene glycol (PEG) as the polyoxyalkylene glycol, where R 1  is hydrogen in the above-described formula, is also useful with the practice of the present invention. The above described ranges of molecular weights and stoichiometries for the polyalkylethylene glycols may suitably be used for the polyethylene glycols.  
     [0041] The polymeric block surfactant compositions of the invention may be produced by different methods or procedures. Two desirable procedures are described below.  
     [0042] According to a first procedure, the inventive polymeric block surfactant compositions are prepared in two stages. In the first stage, complex monocarboxylic acid, from which the component A is to be derived, is obtained by interesterification of a monohydroxy monocarboxylic acid in the presence of a nonhydroxylic monocarboxylic acid. In the second stage, this complex monocarboxylic acid is reacted with the alkyl glycol or polyalkylene glycol, from which the component B is to be derived, in a molar ratio from about 1:1 to about 2:1, respectively. The hydroxyl group in the monohydroxy monocarboxylic acid, and the carboxyl group in either carboxylic acid, may be primary, secondary or tertiary in character. Suitable hydroxycarboxylic acids for use in the first stage include glycolic acid, lactic acid, hydracrylic acid and, in particular, 12-hydroxystearic acid. Nonhydroxylic carboxylic acid acts as a chain terminator and hence acts as a means of regulating the molecular weight of the complex monocarboxylic acid. The nonhydroxylic carboxylic acid may be, for example, acetic acid, propionic acid, caproic acid, in particular, stearic acid, or an acid derived from a naturally occurring oil, such as tall oil fatty acid. Commercial quantities of 12-hydroxystearic acid normally contain about 15 weight percent of stearic acid as an impurity and can conveniently be used without further admixture to produce a complex acid of molecular weight about 1,500 daltons to about 2,000 daltons. Moreover, the nonhydroxylic monocarboxylic acid may be separately introduced to produce a complex monocarboxylic acid of a desired molecular weight.  
     [0043] The interesterification of the monohydroxy-monocarboxylic acid and the non-hydroxylic monocarboxylic acid may be effected by heating the starting materials alone or in a suitable hydrocarbon solvent, such as toluene or xylene, which is able to form an azeotrope with the water produced in the esterification reaction. These reactions are typically carried out in an inert atmosphere, e.g., nitrogen, and at a temperature of up to 250° C. Where the hydroxyl group is secondary or tertiary, the temperature employed should not be so high as to lead to dehydration of the acid molecule. Catalysts for the interesterification, such as p-toluene sulphonic acid, zinc acetate, zirconium naphthenate or tetrabutyltitanate, may be included, with the object of either increasing the rate of reaction at a given temperature or of reducing the temperature required for a given rate of reaction. A preferred method of carrying out the interesterification is to effect the reaction at an elevated temperature without hydrocarbon solvent and by using a stream of inert gas to remove the water produced.  
     [0044] In the second stage of the first procedure for obtaining the polymeric block surfactant compositions of the present invention, the complex monocarboxylic acid prepared in the first stage is reacted with the alkyl glycol or polyalkylene glycol. For each molar proportion of the glycol, there are taken from about 1 to about 2 molar proportions of the acid. The reaction is suitably carried out under the same conditions as have been described for the first stage.  
     [0045] According to the second procedure for obtaining the polymeric block surfactant compositions of the present invention, the two reactions described above are carried out simultaneously, that is, the monohydroxy-monocarboxylic acid, the nonhydroxylic monocarboxylic acid and the alkyl glycol or polyalkylene glycol are all heated together in the same proportions as would have been taken for the first procedure, in the presence or absence of a hydrocarbon solvent, at a temperature of up to 250° C. Optionally, the reactions may occur in the presence of a catalyst as described above.  
     [0046] The polymeric block surfactant compositions of the present invention obtained by these two different procedures are similar in composition and characteristics but, because of its simplicity and consequent greater economy, the second procedure is generally preferred.  
     [0047] The surfactant compositions of the present invention are useful as fabric finishing compositions for imparting wicking to a textile fiber or fabric, particularly a synthetic textile fiber or fabric. As used herein, “synthetic textile” and variants thereof refer to a textile made from commonly available polymeric compositions. Nonlimiting synthetic textile fibers or fabrics include those that can be made from polymers, such as, for example, polyamides, polyolefins, polyesters, polyvinyl alcohols, polyurethanes, polyvinyl chlorides, polyfluoro hydrocarbons, polystyrenes, poly(ethylene vinyl acetates), ethylene n-butyl acrylates and cellulosic and acrylic resins. Polyolefins, such as, polyethylene, polypropylene, polybutylene, and copolymers thereof, are especially useful with the practice of the present invention. Moreover, nonwoven synthetic fibers are useful with the present invention because the nonwoven material has numerous passageways for liquids to travel therethrough. As used herein “nonwoven” and variants thereof refer to a textile structure of individual fibers or filaments which are interlaid, but not an identifiable repeating manner. Nonwoven textiles can be formed by a variety of processes, for example, meltblowing and melt spinning processes, spunbonding processes, and the like.  
     [0048] The nonwoven textiles are useful as a liner or cover stock in baby diapers, feminine hygiene products, adult incontinence products, and the like. Nonwoven textiles having the surfactant compositions of the present invention applied externally to the synthetic fibers are especially useful in these applications because of the improved wicking effect imparted by the surfactant compositions. The present invention, however, is not limited to nonwoven textiles and other textiles, such as woven textiles, knitted textiles, braided textiles and the like, may suitably be used. For example, an athletic article, such as a knitted or woven shirt, may suitably be coated with the surfactant composition of the present invention to facilitate the removal of perspiration away from the skin.  
     [0049]FIG. 1 depicts a schematic view of a portion of an article  10 , such as a baby diaper, a feminine hygiene product, an adult incontinence product, and the like, having a cover stock  12 . As depicted in FIG. 2, the article  10  may further include an absorbent layer  14  and an outer cover  16 . An aqueous fluid (not shown) is capable of passing through the cover stock  12  into the absorbent layer  14  where it is absorbed. The outer cover  16  provides mechanical integrity by securing the absorbent layer  14  between the cover stock  12  and the outer cover  16 . The outer cover  16  may also be somewhat impermeable to the passage of the aqueous fluid to aid in the retention of the aqueous fluid within the absorbent layer  14   
     [0050] Desirably, cover stock  12  is a nonwoven textile comprising a plurality of textile fibers, one of which is schematically depicted in FIG. 3 as textile fiber  18 . As depicted in FIG. 4, textile fiber  18  may be externally coated with a surfactant composition to provide a surfactant coating  20  over the textile fiber  18 . The present invention is not limited to having the surfactant coating  20  encompassing the entire external surface of textile fiber  18 , and only portions of the textile fiber  18  may be coated with the surfactant compositions of the present invention.  
     [0051] In many textile applications it is desirable to have fabric finishing compositions that are free of hydrocarbon solvents, and the polymeric compositions of the present invention may be so suitably prepared. Moreover, the surfactant compositions of the present invention may be applied as is to a textile fabric or the surfactant compositions may be diluted with an aqueous solution, such as water. In the latter case, the resulting mixture should be a dispersion of the surfactant composition within the water, i.e., the polymeric surfactant should not be insoluble with water.  
     [0052] The inventive compositions are generally dispersible or soluble in water or can be combined with emulsifiers for dispersion in aqueous solutions. When the inventive compositions have a hydrophilic-lipophilic balance (HLB) of less than about 8, which means that they were insoluble or slightly dispersible in water, emulsifiers may be combined with the surfactant compositions of the present invention to improve dispersibility or solubility in water. The HLB can be estimated by the weight fraction of the hydrophilic moieties in a molecule times twenty. When oxyethylene is the only hydrophilic group in a molecule, the HLB can be estimated from the weight percent of the oxyethylene divided by 5. Useful emulsifiers include sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene fatty acid esters, polyoxyethylene alcohols and polyoxyethylene glycerides. Useful polyoxyethylene glycerides include, but are not limited to, Cirrasol™ G-1282 emulsifier (POE 25 castor oil), Cirrasol™ G-1284 emulsifier (POE 40 castor oil), Cirrasol™ G-1292 emulsifier (POE 25 hydrogenated castor oil) and Cirrasol™ G-1300 emulsifier (POE 100 castor oil), all of which are commercially available from Uniqema, New Castle, Delaware.  
     [0053] The wicking ability or capillarity of a fabric finishing composition is often indicated by the speed of an aqueous liquid passing through a fabric treated with the composition. Durability of the finishing composition is often determined by comparing these speeds after multiple treatment with the aqueous liquid. A Lister strike through apparatus from Lenzing Technik is a convenient apparatus for measuring the efficiency the treated fabric transports an aqueous fluid, such as synthetic urine, through the fabric. The compositions of the present invention have good wicking ability as evidenced by Lister strike through test results of about five seconds or less. Moreover, the surfactant composition of the present invention maintain such wicking ability even after multiple treatments with the aqueous fluid, i.e., the inventive compositions are durable and do not tend to wash off the textile fabric upon contact with aqueous fluids.  
     [0054] The A-B and the A-B-A polymeric surfactant compositions of the present invention also reduce a fabric-to-metal coefficient of friction to less than about 0.9 when applied to a textile fiber. Such fabric-to-metal friction values are generally considered to be reasonably low to those skilled in the art. The compositions of the present invention exhibit such low fabric-to-metal friction values and are also durable on a textile, thereby imparting a hydrophilicty to the fabric. Desirably, the durability of the compositions on the fabric is less than five seconds after a multiple of at least five insult strike-through Lister tests. Details of the Lister test is described below in conjunction with the examples. The combination of lubricity, as indicated by enhanced fabric-to-metal friction values, and durable hydrophilicty, as indicated by low Lister strike through values on multiple treatments with an aqueous fluid, provide the inventive compositions with useful fiber finishing characteristics.  
     [0055] The polymeric block surfactant compositions of the present invention have alternating hydrophilic polyoxyalkylene glycol blocks and hydrophobic polyhydroxycarboxylic acid blocks. The hydrophilic blocks function to provide a wicking action of aqueous liquids on a synthetic textile fiber. The hydrophobic blocks function to repel aqueous fluids from the synthetic textile fabric. The amounts, such as the above-described molecular weights, of the alternating blocks are controlled to provide compositions that provide durable surfactant finishes on synthetic textile fabrics or fibers.  
     [0056] A method for treating synthetic textile fibers or fabric includes applying the inventive surfactant compositions to such textiles. Desirably, the compositions are applied as is or applied as an aqueous dispersion. The composition of the present invention may be applied to the textile fiber or fabric by dipping, soaking, spraying, or applying by other suitable means. The compositions of the present invention may be applied from about 0.05 to about 10 weight percent on the textile fiber or fabric. Desirably, the inventive compositions are applied from about 0.1 to about 1.0 weight percent on the fabric or fiber.  
     [0057] The present invention is further described below in the following examples, which are intended to further elucidate the invention, and are not to be construed, in any way as limiting.  
     EXAMPLES  
     Example 1  
     Inventive Formulations Prepared  
     [0058] A-B and A-B-A block polymers of the present invention were prepared with different molecular weights of mPEG and PEG and with different moles of PHS as shown in Table 1 below. The number of PHS moles represent the total number of moles of PHS present in the inventive composition.  
               TABLE 1                          Inventive Compositions                                 Inventive   mPEG   PEG   PHS   Est&#39;d       Composition No.   Mol. Wt.   Mol. Wt.   Moles   HLB                                          1 (A-B)   350   —   4.5   4.3        2 (A-B)   750   —   4.5   7.4        3 (A-B)   1,450   —   4.5   12.2        4 (A-B)   2,000   —   4.5   10.7        5 (A-B)   5,000   —   4.5   15.9        6 (A-B)   1,450   —   2   14.4        7 (A-B)   1,450   —   7   8.5        8 (A-B-A)   —   200   12   2.1        9 (A-B-A)   —   600   12   5.2       10 (A-B-A)   —   1,000   12   7.4       11 (A-B-A)   —   1,450   12   9.2       12 (A-B-A)   —   3,200   12   13.1                  
 
     [0059] The inventive compositions had estimated HLB values from about 2 to about 16.  
     [0060] Cirrasol™ G-1292 emulsifier (POE 25 hydrogenated castor oil) was blended at 30% with all of the inventive compositions. Cirrasol™ G-1292 emulsifier, which has an estimated HLB of about 10.8, was blended to improve dispersion in water, especially for the inventive compositions that have low HLB values, for example, an HLB of about 8 or less.  
     [0061] The blended compositions were applied to finish-free polyester yarn (250 denier/50 filaments) by using the Atlab® finish applicator. The Atlab® finish applicator used a syringe pump to deliver the finish solutions by a glass applicator to the fiber. The finishes were diluted in water to a concentration which was determined by the desired % FOY (finish on yarn), fiber type, denier, and application speed. The treated fiber is wound up on a cone. The % FOY was determined from the following formula:  
     %  FOY =(Finish Weight/Fiber Weight)*100%.  
     [0062] The blended compositions were also applied to finish-free 20 g/m 2  polypropylene fabric (spunbond) by padding the compositions on the fabric. The fabric was immersed into a dilution of water and the finish. The excess dilution was squeezed off the fabric by a padder (Poterala Mfg. Co., Inc. Laboratory Pad Model VP Series). The concentration and amount of the dilution applied to fabric was determined by the desired % FOF (finish on fabric) and % WPU (wet pick-up). The fabric was dried in an oven (Werner Mathis AG Laboratory Drying Oven Type LTF) at 110° C. for 3 minutes. The % FOF and the % WPU were determined as follows:  
     %  FOF =(Finish Weight/Fabric Weight)*100%, and  
     %  WPU =[(Fabric Weight WET −Fabric Weight DRY )/Fabric Weight DRY ]*100%.  
     [0063] These dispersions were applied to polyester fiber and polypropylene fabric at -0.5% (based on weight).  
     [0064] Control samples, i.e., Cirrasol™ G-1292 emulsifier, Cirrasol™ G-2109 fabric finish and Cirrasol™ G-1962 fabric finish, were summarily prepared and applied the polyester fiber and the polypropylene fabric as described above. The control samples are commercial fabric finishing products available from Uniqema, New Castle, Delaware.  
     Example 2  
     Fiber-to-Metal (F/M) and Fiber-to Fiber F/F) Friction Testing  
     [0065] A Rothschild Friction Meter (F-1188) was used to determine the force of friction of the treated yarn that was pulled across another surface. In the case of Fiber-to-Metal (F/M) friction, a stainless steel metal pin was used as the metal surface. The fiber was pulled across the surface of the metal pin at 300 m/min. The frictional result is determined by using the Eytelwein formula, as follows:  
     μ=[log( T   2 )−log( T   1 )]/α 
     [0066] where μ—coefficient of friction,  
     [0067] T 1 —yarn tension before friction pin,  
     [0068] T 2 —yarn tension after friction pin, and  
     [0069] α—angle in which fiber is in contact with the metal pin (arc).  
     [0070] The angle (α) was set at 180°. The pretension (T 1 ) was set at 20 cN. The friction testing was performed at 70° F. and 65 percent relative humidity. The results of the Fabric-to-Metal Testing are shown below in Table 2.  
     [0071] The inventive compositions had improved F/M friction values as compared to Cirrasol™ G-1292 emulsifier and Cirrasol™ G-1962 fabric finish as evidenced by the lower FIM friction values.  
     [0072] The Rothschild Friction Meter (F-1188) was also used to determine the Fiber-to-Fiber (F/F) friction. The metal pin in the F/M setup was replaced with a frictionless wheel. The fiber was twisted around itself 3 times (˜1080°) to form a loop which was placed on the wheel. The fiber was pulled against itself at 1 cm/min. The pretension, T 1 , was set at 39 cN. The F/F was also determined by the above-described Eytelwein formula. The friction testing was performed at 70° F. and 65 percent relative humidity.  
     [0073] The results of the Fabric-to-Fabric testing are also shown below in Table 2.  
     [0074] The inventive compositions had improved Fabric-to-Fabric (F/F) values over the Cirrasol™ G-1292 emulsifier and Cirrasol™ G-2109 fabric finish as evidenced by the lower F/F friction values.  
               TABLE 2                          Fabric-to-Metal (F/M) Friction and Fabric-to Fabric (F/F)       Test Results                                         mPEG   PEG   PHS   μ,   μ,           Mol. Wt.   Mol. Wt.   Moles   F/M   F/F                                                 Inventive                           Composition No.        1 (A-B)   350   —   4.5   —   —        2 (A-B)   750   —   4.5   0.87   0.14        3 (A-B)   1,450   —   4.5   0.86   0.15        4 (A-B)   2,000   —   4.5   0.86   0.14        5 (A-B)   5,000   —   4.5   0.81   0.14        6 (A-B)   1,450   —   2   0.86   0.15        7 (A-B)   1,450   —   7   0.87   0.14        8 (A-B-A)   —   200   12   0.86   0.16        9 (A-B-A)   —   600   12   0.86   0.13       10 (A-B-A)   —   1,000   12   0.87   0.15       11 (A-B-A)   —   1,450   12   0.87   0.13       12 (A-B-A)   —   3,200   12   0.86   0.15       Control       Compositions       Cirrasol ™ G-1292   —   —   —   0.88   0.18       emulsifier (1)         Cirrasol ™ G-2109   —   —   —   0.83   0.12       fabric finish (2)         Cirrasol ™ G-1962   —   —   —   0.91   0.04       fabric finish (3)                                            
 
     Example 3  
     Liquid Strike Through Testing  
     [0075] The speed of liquid passing through a fabric and durability of the fabric finishing compositions were determined by using a Lister strike through apparatus from Lenzing Technik. This test was used to quantify the efficiency of the treated fabric for transporting synthetic urine through the fabric (diaper application).  
     [0076] This test determined how fast a liquid (synthetic urine) passed through a nonwoven fabric (20 g/m 2  spunbond polypropylene) which was treated with finish at 0.5% FOF. When the same sheet of fabric was tested several times in the same spot, this test showed how durable the hydrophilic finish was to the fabric. In other words, it determined how easy or difficult it was to rinse off the finish.  
     [0077] The time was determined by a Lister apparatus (Model 1996) from Lenzing Technik, Austria. The treated fabric was placed on top of five sheets of filter paper (Fa. Hollingsworth &amp; Vose Comp., LTD. Grade: ERT/FF3), which absorbed the synthetic urine that passed through the fabric. A “strike-through-plate” was placed on top of the fabric. The synthetic urine was discharged through the hole in the center of the “strike-through-plate,” which had electrodes in the bottom of the hole. The synthetic urine completes a circuit (which runs the timer) when it is in contact with the electrodes. When all of the synthetic urine passed through the fabric, the circuit is broken and the timer stops. In this method 5 ml of synthetic urine per test was used.  
     [0078] After each test, the fabric was allowed to dry. The test was repeated on the dried fabric with fresh filter paper. The results of the Lister strike through test are shown below in Table 3.  
               TABLE 3                          Lister Liquid Strike Through Test Results                                     mPEG   PEG       Time (seconds) for           Mol.   Mol.   PHS   Insult No.:                                                     Wt.   Wt.   Moles   1   2   3   4   5                                                             Inventive                                       Composition No.        1 (A-B)   350   —   4.5   4   4   4   4   5        2 (A-B)   750   —   4.5   4   4   4   4   4        9 (A-B-A)   —     600   12   4   5   5   5   5       11 (A-B-A)   —   1,450   12   5   4   5   4   5       Control       Compositions       Cirrasol ™ G-2109   —   —   —   3   7   9   24   23       fabric finish       Cirrasol ™ G-1962   —   —   —   3   3   3   3   4       fabric finish                  
 
     [0079] The inventive compositions provided excellent hydrophilic finishes to the fabric. The inventive compositions had improved hydrophilic finish and improved durability of the finish as compared to Cirrasol™ G-2109 fabric finish.  
     [0080] While there have been described various aspects of the present invention, those skilled in the art will realize that various aspects and embodiments can be made without departing from the spirit of the present invention, and it is intended all such further modifications and changes be included within the scope of the claims.