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The chemistry of a polyamide–epichlorohydrin resin (hercosett 125) used to shrink‐resist wool
Abstract
A polyamide–epichlorohydrin resin used to shrink-resist wool [Hercosett 125 (Hercules Inc.)] was separated by ultrafiltration into fractions A, B, and C (in the approximate proportions 60, 40, and 2 by weight), which correspond to the three peaks in size exclusion chromatograms (SEC). Viscosity, spectra, and SEC results as well as results of experiments on the reaction of the parent polyamino–polyamide (PAA) with epichlorohydrin indicated that fraction A was high-molecular-weight crosslinked material whereas fraction B was essentially uncrosslinked. Fraction C was minor impurity, possibly a mixture containing a triazine, and it was also found in the PAA from which the original resin was prepared. High-resolution proton NMR spectra of the Hercosett 125 indicated that chlorohydrin or epoxy groups were absent, and thus confirmed an earlier 13C-NMR study that only azetidinium reactive groups were present. Two reactions are believed to occur in Hercosett 125 on storage: hydrolysis of azetidinium to dihydroxypropyl groups and hydrolysis of backbone amides. The small differences in the properties of wool treated with either A or B fractions, and those of wool treated with unfractionated Hercosett 125, were related to the extent of crosslinking before and after curing. As the extent of crosslinking increased, the amount of staining by an anionic dye decreased, and the shrink resistance improved slightly.
... The mechanism of synthesis of Hercosett 125 resin is shown in Fig. 5. Adipic acid is reacted with diethylenetriamine to form poly (diethyleneiminoadipamide) through the condensation polymerization. This polydiethyleneiminoadipamide is again reacted with epichlorohydrin to form poly(chloro-hydroxypropyldiethylene adipamide ammonium chloride), which is marketed as Hercosett 125 resin [28]. In the presence of an alkali, the chlorohydroxypropyl groups of this quaternary ammonium polyamide are converted into epoxy groups forming poly(epoxypropyldiethylene adipamide ammonium chloride) that can react with carboxyl and hydroxyl groups available in wool fiber surface as shown in Fig. 6. ...
... Levene and Cohen investigated one-step oxidation of wool fabric with magnesium monoperoxyphthalic acid (MMPP) at an acidic pH and found that at the applied concentration of 3.0-6.0% owf provided excellent shrink-resistance [28]. Ozone alone or ozone/bisulfite treatment was found ineffective at providing durable shrink-resistance to wool fibers [65]. ...
Wool fiber is a natural protein fiber, which is used for the manufacturing of apparels, and floorcoverings because of its excellent fire retardancy, stain-resistance, antistatic and odor control properties along with exceptional warmth and resilience. However, wool fiber has several serious demerits, such as garments made of wool fibers extensively shrink during their laundering. To overcome this problem, wool fibers, especially those are used in apparel, are frequently shrink-resist treated to make them machine-washable. A wide range of treatments including oxidative, enzymatic, radiation, polymeric coatings, sol-gel coatings, and plasma treatments have been investigated to make wool fiber shrink-resistant. In this review, the mechanisms of wool fiber shrinkage, the research carried out until recently to make wool fiber shrink-resistant, and the current status of the sustainable alternatives developed, have been compiled and presented. The various methods investigated have been critically discussed with their merits and demerits, shrink-resist performance, and their shrink-resistance mechanisms. The chemistry and synthesis of various polymers used for the shrink-resistance and their reactions with wool fiber have been outlined. This review also includes the current challenges to make shrink-resist treatments green and sustainable, and also the future directions to meet these challenges. Some of the treatments investigated may affect the biodegradability of wool fibers, especially those are based on coating with synthetic polymers. A sustainable alternative polymeric coating based on sustainably produced polymeric resins, especially bio-based resins, needs to be developed so that the future treatments become sustainable.
... Polyethyleneimine can only be used for absorbent wet paper without sizing treatment, and dialdehyde starch can only provide materials with temporary wet strength [22][23][24]. To overcome these limitations, a type of efficient wet strength agent, polyamide epichlorohydrin resin has been used to improve the wet strength without losing the softness and absorbency of wet-laid materials [25][26][27]. This wet strength agent may be a good choice for various applications such as personal hygiene care and medical care without regard to environmental pollution. ...
Developing wet-laid papers with a good wet strength remains a longstanding challenge in the papermaking industry. In this study, hydroentanglement, a mechanical bonding technique is developed to consolidate the wet-laid fibre web. The results indicate that wet tensile strength, ductile stretching property, softness, air permeability and water absorbency of the wet-laid fibre web are significantly improved by hydroentanglement. In addition, the abrasion test shows that the dusting off rate of wet-laid fibre web can be effectively reduced through hydroentanglement. Moreover, the disintegration experiment proves that wet-laid hydroentangled nonwovens could be easily dispersed when compared with conventional carded hydroentangled nonwovens. Therefore, the new wet-laid hydroentangled nonwovens can maintain excellent performance in a wet state, showing a great potential for personal hygiene applications.
... The advantages of azetidinium groups in this application are: (a) inhibition of bacterial growth via interaction with cell components due to the cationic nature of this group [15,16] and (b) improving the adhesion via both (i) ionic interaction and (ii) covalent linkage. The four membered rings attached to the polymers react with the functional groups on the surface forming covalent bonds [17]. ...
In this work, we report the antimicrobial efficacy of azetidinium functionalized polytetrahydrofurans in solution and their application in the preparation of non leaching, antimicrobial surfaces. The excellent antimicrobial efficacy of these water soluble polymers both in solution and on surfaces (>99.99%-100% bacterial growth inhibition) makes them excellent candidates for solving the hygiene related problems in the medical and hospital environment.
... To facilitate chemical accessibility, normally this chemical bound hydrophobic layer is removed. The most popular processing technique is the Hercosett chlorination process (10), in which wool fibre was first chlorinated in a solution containing active chlorine, followed by cross-linking of a layer of polymer onto the surface to provide the wool with a superior washing ability (compared to untreated wool). Enzyme immobilization onto this surface can then achieved by using a glutaraldehyde (GA) cross-linking agent. ...
The aim of this research was to examine the effectiveness of an enzyme in enhancing the cleaning effectiveness of woollen fabric without addition of any detergent. As a model enzyme, lipase from Pseudomonas fluoresces was immobilized onto a woollen cloth using a unique protocol that involved: chlorination of the wool, adsorbing a polyethyleneimine (PEI) spacer, adsorbing and cross-linking with glutaraldehyde (GA) followed by adsorption of the lipase. It was determined that for this protocol, the immobilized activity was dependent on the GA solution pH and not on its concentration. The cloth exhibited excellent oily stain removal ability: after being stained with olive oil and stored for one day in air at room temperature, the oily stain could be easily removed by 0.05 M pH 8.5 Tris buffer without any detergent addition. This enhanced cleaning was stable also over a period of one month. The activity of the cloth (based on activity assay) dropped considerably over just 15 days storage in air. This therefore likely indicates that the enhanced cleaning seen over an extended storage period may not require as high an enzyme activity. The activity of the immobilized lipase was also very stable when stored under near ideal conditions: when the immobilized cloth was stored in 0.05 M Tris buffer (pH 8.5) for more than 80 days in a refrigerator, more than 80% of the lipase activity remained. Overall, results indicate that this immobilization protocol is a promising step towards producing a woollen fabric with enhanced cleaning properties. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 2014.
Non-ionic water-borne polyurethane HSi-WPU was synthesized with isophorone diisocyanate and self-synthesized polysiloxane block polyether as raw materials, with diethylenetriamine utilized as an internal crosslinking agent. The effects of reaction conditions were intensively studied, as molar ratio, reaction temperature, reaction time, and diethylenetriamine dosage on the properties of HSi-WPU were discussed to optimize the synthetic condition and applied the optimal synthetic HSi-WPU to the anti-shrinkage finishing of wool fabric. The chemical structure of HSi-WPU was confirmed via FT-IR and 1H NMR. Good thermal stability of HSi-WPU was noticed, with decomposition of the polymer starting at 300 °C. Surface morphology analysis demonstrated that the wool scale was covered by a thin layer of HSi-WPU film. The anti-shrinkage property of wool fabric finished with HSi-WPU was significantly improved.
Textile coatings usually provide material layers which adhere to the textile structures. A typical textile coating formulation generally contains polymeric binder(s) along with other additives (such as colorants, adhesion promoter, biocide, plasticizers, etc.) which are applied in the form of a solution or a dispersion or a paste or a similar fashion using a spreading technique onto a textile fabric. Different types of techniques are commonly used for textile coatings, for examples, spray coating techniques, the application of nanoscale technologies, biotechnology, and plasma technology. Certain coating technologies including digital coating technology have many industrial potentials in order to produce higher performance coated textiles with a variety of conventional and functional properties. Textiles with multifunctionalities are increasingly demanded as a part of advanced and future marketing strategies, for instance, garments and technical textiles for outdoor environments can have novelty and durable self-cleaning properties at the same time. Various ways are usually used to impart novelty and functionality into coated textiles. For example, sol–gel chemistry is one of many techniques which can be used to produce superhydrophobic coated textiles suitable for many high-tech and general application purposes. This chapter provides selective pieces of information on different types of popular textile coatings and related specific features which have pronounced impacts on the behaviors of coated textiles. It also briefly provides some selective pieces of information on different advancements in textile coatings in consideration to the applications of new advanced techniques as well as frequently used general coating techniques (such as spraying, padding, etc.) to produce high-performance coated textiles for conventional and high-tech applications.
Hybrid organic–inorganic coatings prepared by the sol–gel method can impart desirable properties to textiles, but may adversely affect properties such as bending rigidity. This study investigated the causes of increased bending rigidity. Woven wool fabric was pad coated with formulations of methyltriethoxysilane (MTES) and Hercosett polyamide resin, examined by scanning electron microscopy, and the bending rigidities were determined. MTES coatings of up to 3.0% solids on mass of wool did not impart unacceptable bending rigidity. The coatings were not uniform on the fiber surfaces, and the increases in fabric bending rigidity could be partially attributed to inter-fiber bonding. In addition, the coatings “pinned” the edges of the cuticle scales, making individual fibers harder to bend. These effects are only weakly dependent on the Young's moduli of the coating materials.
The wet tensile strength of paper made with polyaminoamide-epichlorohydrin (PAE) was found to depend on the resin's relative equivalent weight based on azetidinium, the most reactive cross linking group in the resin. The wet tensile strength of PAE treated paper increased as a function of increasing relative azetidinium equivalent weight for a series of PAE resins having different molecular weights and quaternary charge densities. This relationship may be used to predict the relative order of performance between PAE resins on paper machines. The structure-activity relationship was observed with wet tensile data from papers made on a pilot fourdrinier paper machine and the same trend was observed in commercial papermaking operations. A laboratory handsheet method did not distinguish any differences between the PAE resins. The relative molecular weights of the resins were determined by size exclusion chromatography (SEC) and the relative azetidinium content was measured by nuclear magnetic resonance (NMR) spectroscopy.
Two macromolecular products, of polyethyleneimine and of polyamineamide type, were synthesized by the polycondensation of triethylenetetramine with 1,2 dichloroethane with adipic acid and ε-caprolactam, respectively. The secondary amine groups of the two polymers were substituted with specific agents, e.g. the reaction product between triethylamine and epichlorohydrin and/or 1,2 dichloroetane, in order to produce their cationization. The intermediates and the polymers were characterized by FTIR spectroscopy, elemental analysis, solution viscometry and polyelectrolyte titration. Some properties of the synthesized polymers such as molecular weight, charge density, inability to crosslink, recommended them as retention or drainage agents in the papermaking, or as purification agents in the waste water treatment.
Cationic amine polyamide-epichlorohydrin (PAE) resin was applied as pretreatment to wool, cotton, and blends of wool/cotton fabrics for subsequent one-step union dyeing with acid dyes according to the conventional wool dyeing process. Compared to cationic biguanide and dimethyloldihydroxyethyleneurea/alkylamine pretreatments, which are known to be effective for one-step union dyeing of wool/cotton blends when applied at levels of 2% to 10% on weight of bath (owb), PAE resins were equally as effective when applied at 1.25% owb for 30 min at 20C. PAE resins provide an efficient alternative to conventional dyeing processes used to achieve union shades and could lead to improved marketability of wool/cotton blends.
Handsheets were prepared with polyamideamine-epichlorohydrin (PAE) resin solutions stored at 4°C and pH 4.2 to 4.5 for up to 8.9 years, and the effects of structural changes of the deteriorated PAE on retention behaviour and wet tensile strength of the handsheets prepared thereof were studied. When stored PAE samples were used, wet tensile strength decreased with increasing PAE storage time. This decrease in wet tensile performance is partly explainable by the decreased PAE retention ratio, which is due to both decreases in 3-hydroxy-azetidinium content and DPn of the stored PAE. On the other hand, the decrease in wet tensile index of the handsheets at the same PAE retention ratio is probably due to the decrease in 3-hydroxy-azetidinium content of the stored PAE rather than the decrease in DPn. When PAE solutions are stored at 4°C, both their wet tensile performance and retention ability on pulp fibres are mostly maintained at least within 9 months.
Functional polymers with azetidinium groups in the backbone are synthesized via the reaction of aminotelechelic polymers, containing primary and secondary amino groups, with epichlorohydrin. During the reaction, the secondary amino groups are transformed into azetidinium groups and the primary amino groups are transformed into amino-chlorohydrin, amino-epoxide, and azetidinium groups. The formation of desired functional groups in the polymer is controlled by tuning the reaction conditions. To understand the influence of reaction conditions generating the desired functional groups, model reactions of primary and secondary amines with epichlorohydrin are studied in detail, including the influence of the mole ratio of the starting materials, effect of solvent, effect of pH, and reaction kinetics.
Graft terpolymers bearing polyether side chains and poly(methacrylate) stems were synthesized by the graft-onto reaction of monoamino-terminated poly(PO9-co-EO1) to poly{[5-(methacryloyloxy)methyl-1,3-oxathiolane-2-thione]-co-n-butyl methacrylate} [poly(DTCMMA-co-BuMA)]. The grafting reaction proceeded via the nucleophilic addition of the terminal amino groups to the five-membered cyclic dithiocarbonate moieties giving thiol moieties, although the grafting efficiency was low (9–34%) due to the steric hindrance of the side chains. The Tg values of the poly{[DTCMMA-graft-poly(PO9-co-EO1)]-co-BuMA} ranged 27–47 °C, depending on the amounts of flexible poly(PO9-co-EO1) chains introduced lowering the Tg values. Poly{[DTCMMA-graft-poly(PO9-co-EO1)]-co-BuMA}s bearing thiol groups were applied for the modification of wool via the disulfide exchange reaction. The modified wool had better dye ability toward a pigment from safflower than the original wool owing to the hydrophilic nature of poly{[DTCMMA-graft-poly(PO9-co-EO1)]-co-BuMA} introduced. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012
The Agricultural Research Service of the U.S. Department of Agriculture conducts research on agricultural products and co-products where wool is a co-product of the American lamb industry. The ARS process, an alternative to conventional peroxide for bleaching and chlorination for shrinkproofing wool, was applied to bleach and control the dimensions of wool, wool/cotton, cotton, and viscose rayon fabrics. Conventional processes for bleaching and shrinkage control have limited economy due to high temperatures and long exposures, and their ecological acceptance is marginal. The ARS process is chemo-enzymatic with bleaching followed by biopolishing with shrinkproofing, both steps being applied at near-room-temperature conditions for 30—40 minutes to reach high levels of whiteness, softness, and dimensional stability. The novelty of the process involves the in situ formation of a hyper-peroxide bleach to achieve high whiteness with subsequent enzyme processing from a fresh bath to selectively treat only the surface scales of wool without damage to the inner cortex of the fiber. The Whiteness Index (WI) of wool and wool/cotton improved 63%—72% after bleaching alone and another ~2% increase after enzyme treatment; area shrinkage was less than 2%. The WI of cotton print cloth improved 60.5% by ARS bleaching compared to 64% by conventional bleaching. The process limited shrinkage of cotton knit to 4% and to less than 2% for cotton and viscose woven fabrics. The mechanical properties of all treated fabrics were retained. In a separate study, the process was applied at high concentration to convert wool jersey into parchmentized jersey with permanent stiffness and 45.5% increase in sheerness, as determined digital image analysis. ARS novel bleaching is a sustainable, facile, effective process for low-temperature bleaching with low energy consumption and low environmental impact. Wool jersey with sheerness, stiffness, and strength retention can be fabricated by treatment with highly concentrated ARS hyper-peroxide bleach.
In earlier work, we established that alkaline hydrogen peroxide systems that include dicyandiamide, gluconic acid, and Triton X surfactant, used alone or followed by enzyme treatments, control shrinkage in wool fabrics to 3.0% and 1.2%, respectively. We have perfected this system for complete shrinkage control with no loss in mechanical properties by using the same pretreatment and enzyme applied from a buffered triethanolamine solution that incorporates sodium sulfite. Fabrics treated by this method are bright white and exhibit a soft handle with a smoothed surface. Digital image analysis is used to quantify fiber projections above the fabric surface for a measurement of smoothness. A statistical analysis with a central composite design reveals the optimum concentrations of enzyme, sodium sulfite, and exposure time that maximize shrinkage control while maintaining adequate levels of tensile strength and weight loss.
Polymer networks are prepared by heat-curing of prepolymers containing cyclic ammonium cations with carboxylate-containing reagents as counter anion.A first part describes the cross-linking of copolymers of N-cyclohexyl-3-azetidinyl methacrylate (CHAM) and methyl methacrylate with hydrogen chloride or mono- or poly-carboxylic acids. Curing temperatures were between 90 and 140 °C and curing times between 3 and 20 min, depending on the CHAM-content and the type of acid used.In a second part, pyrrolidinium ion containing (co)polymers were reacted with carboxylate ion containing (co)polymers to form the corresponding inter polymer complexes (IPCs) which were subsequently heat-cured. The first was an IPC obtained by mixing the water-soluble (co)polymer of N,N-diallylpyrrolidinium chloride (DAPC) with sodium acrylate (co)polymer. Heating of the dry IPC film or powder resulted in ring-opening of the pyrrolidinium ions by the carboxylate ions leading to covalent networks. A second type of IPC was obtained by mixing copolymers of N-(vinyl benzyl)pyrrolidine (VBP) with acrylic acid copolymers. The thus obtained IPCs are transformed into covalent polymer networks by curing at 130 °C. Also IPCs with different structural units (for ex. VBP-Styrene copolymer with acrylic acid-butyl acrylate copolymer) could be formed and cured leading to polymer-co-networks.
A novel series of adsorbents have been prepared by reacting adipic acid, diethylenetriamine, epichlorohydrin, and cellulose. The structural features of these polyamide-epichlorohydrin-cellulose (PAE-Cell) polymers have been confirmed by IR analysis. The ability of PAE-Cell polymers to adsorb direct dyes from aqueous solution has been evaluated in a fixed bed column system. These PAE-Cell polymers have been found to exhibit a better capacities for direct dye removal than some commercial activated carbons.© 1993 John Wiley & Sons, Inc.
The copolymer (PGS) synthesized by polymerization of glycidyl methacrylate with styrene had a significant effect on paper wet strength. Factors such as retention aids, curing temperature, and curing time were investigated. The results showed that among four kinds of partially aminated poly N-vinylformamide (APNVF), APNVF-4 that had the highest charge density was the most effective for strengthening paper. The effectiveness of the retention systems increased with their wet functionality in the order APNVF-4 > C-PAM ≈ PAAm > PEI > PDADMAC. The curing temperature and curing time had little influence on paper dry strength, but they influenced paper wet strength greatly. The FTIR studies on model reactions showed that glycidyl groups could react with amino groups and carboxyl groups under common curing conditions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2791–2797, 2001
The titrations of the polyammamides prepared from adipic acid and diethylenetriamine or di(3-aminopropyl)methylamine were monitored by means of natural-abundance 15N-(NMR) nuclear magnetic resonance spectra. Opposite shift effects were found for amine and amide nitrogens upon protonation of the amino groups. These shift effects allow one to distinguish substitutions involving exchange of electric charges from other substitutions without isolation of the polymers. Reactions of the polyaminamides with β-propiolactone, -butyroslution, methyl-methane sulfonate, prolyleneoxide, epichlorohydrine, maleic acid anhydride, succinic acid anhydride, carbon dioxide, ethylchloroformate, and methyne sulfonylchloride were carried out in water, and the resulting polyelectrolytes were characterized by means of 15N-NMR spectra.
Several non-cross-linking cationic polymers have been found to improve the shrink-resistance of chlorinated wool. The polymers, applied by exhaustion from neutral to alkaline liquors, do not require a curing operation. Three polymers in particular, poly(vinylbenzyltrimethyl ammonium chloride), a butyl methacrylate–trimethylammoniumethyl methacrylate copolymer, and an octyl methacrylate–trimethylammoniumethyl methacrylate copolymer, were more effective, at low treatment levels, than Hercosett 125, currently used in commercial processes. Cross-staining by dyes during laundering of fabric treated with the methacrylate copolymer was less than with fabric treated with the same level of Hercosett 125.
The gel permeation chromatography of cationic polymers, a polyamide—epichlorohydrin resin (Hercosett 125), poly(2-vinylpyridine) and polyethyleneimine, was compared on a selection of silica gel columns with neutral and cationic surface modifications.The elution volumes of the polymer peaks were very dependent on the pH, ionic strength and the column, but were also influenced by the type of salts in the eluent and the polymer concentration. In some cases it was possible to elute the cationic polymer anywhere between the high-molecular-weight exclusion limit and the low-molecular-weight total permeation limit.The polymer peak in Hercosett 125 split into two under certain conditions. This appears to be related to the presence in Hercosett 125 of polymers of different structures.Universal calibration methods and viscosity measurements have been used to indicate conditions where interaction between the cationic polymers and the columns and/or solvent was minimal and these conditions have been used to estimate the molecular weight of Hercosett 125.
The efficacy of oxidatively crosslinked starch xanthate for improving wet- and dry-strength properties of paper prompted the present study of an alternative, interpolymeric crosslinking procedure. Sodium starch xanthate of degrees of substitution 0.05–0.25 was reacted with a commercial paper additive (a polyamide–polyamine–epichlorohydrin wet-strength resin) which was found to contain 3-hydroxyazetidinium chloride, epoxy-propyl, and chlorohydrin groups (3:1:1) to give an interpolymer crosslinked by both ionic and covalent bonds. Model systems, in conjunction with nuclear magnetic resonance, infrared, and ultraviolet spectral data, served to elucidate reaction mechanisms and structures of the interpolymer and the commercial resin. Reaction conditions that favored formation of either ionic (polysalt) or covalent (xanthate ester) crosslinks were investigated. In preliminary evaluations, incorporation of the interpolymer into paper handsheets resulted in excellent wet- and dry-strength improvements.
Ion Containing Polymers
- A. Eisenberg
- M. King
Fries thesis Rheinisch Westfaischen Technischen Hochschule Aachen
- W De