The discriminant principle of environmental protection textile auxiliaries

At present, the discriminating principles of environmentally friendly textile auxiliaries are as follows:

1. High biodegradability

The biodegradability of textile auxiliaries means that under certain conditions, textile auxiliaries are oxidized and decomposed by microorganisms to generate carbon dioxide, water and inorganic elements, making them harmless substances. The biodegradability of surfactants as textile auxiliaries generally has the following rules:

a. Anionic surfactants

The degree of biodegradability was as follows: linear fatty soaps > higher fatty alcohol sulfatates > linear ether sulfatates (AES)> linear alkane and olefin sulfonates (SAS, AOS)> linear straight alkane sulfonates (LAS)> branched higher alkane sulfatates > branched ether sulfatates > branched alkane benzene sulfonates (ABS).

Obviously, the biodegradability of anionic surfactants with branched-chain structure is poor, such as the detergent made of sodium tetrapolypropylene alkane benzene sulfonate is not easy to biodegrade because of more branched-chain.

b. Nonionic surfactants

Its biodegradability is related to the length of the polyoxyethylene chain (EO)n, the larger the n number, the longer the chain, the more difficult the degradation, such as the biodegradation rate of alkylphenol polyoxyethylene ether with n=10 is much lower than that of penetrant JFC(n=5) and emulsifier MOA(n=3~4).

c. Cationic surfactants

Because of its high toxicity, it often kills biological bacteria and prevents biodegradation.

2. Low toxicity

The toxicity of textile auxiliaries includes acute toxicity, fish toxicity and bacterial and algal toxicity. Acute toxicity is expressed as the semi-lethal amount of acute poisoning resulting in death of the tested animal after a single oral, injection or skin application of additives, that is, LD50, in g/kg. The LD50 of linear alkane (C12~14) sodium sulfonate, alkyl benzene sulfonate, linear ether sulfate and phosphate containing alkyl phenol polyoxyethylene ether are in the range of 1.0~2.0 In the range of g/kg, the LD50 of dodecyl alcohol polyoxyethylene (7) ether, octadecyl alcohol polyoxyethylene (10) ether, octadecyl alcohol polyoxyethylene (20) ether and nonylphenol polyoxyethylene (9~10) ether are all in the range of 1.5~4.1 In the range of g/kg, they all have strong acute toxicity, while cationic surfactants such as cetyltrimethyl ammonium oxide and cetylpyridine chloride have strong acute toxicity with LD50 below 1.0 g/kg. The toxicity of textile additives to aquatic bacteria and algae is expressed by ECO50, which refers to the nature of the degree of inhibition of textile additives to the movement of aquatic bacteria and algae within 24 hours. The ECO50 of most anionic and non-ionic surfactants is in the range of 1~100 mg/L, if the ECO50 is in 1 mg/L below indicates that the textile additive is highly toxic to aquatic bacteria and algae.

3, low formaldehyde or no formaldehyde

The requirements for the amount of formaldehyde produced by free and partially hydrolyzed textile additives are the same as those for dyes, that is, to ensure that the amount of formaldehyde produced by free and partially hydrolyzed on the fabric cannot exceed 30 mg/kg for textiles in direct contact with the skin, and cannot exceed 300 mg/kg for all other textiles.

4, can not contain environmental hormones

At present, most of the 70 prohibited environmental hormones identified in the world market are related to the textile auxiliaries industry, and the main environmental hormones are polychlorinated dioxins, polychlorinated biphenyls, polybrominated biphenyls, alkyl phenols, p-nitrotoluene, pentachlorophenol, and o-(p-) phenylphenol.

5, the content of extractable heavy metals can not exceed the allowable limit of heavy metals on the human body and aquatic organisms more and more people understand and attach importance to, the European Union stipulates that the content of extractable heavy metals in textile auxiliaries is the same as the limit value in dyes, they do not include heavy metals as part of the molecular structure of auxiliaries.

6, does not contain or will not be cracked under specific conditions (that is, specific reduction conditions) to produce 24 carcinogenic aromatic amines. These carcinogenic aromatic amines have the same toxicity and name as the carcinogenic aromatic amines prohibited in dyes.

7, does not contain adsorbable organic halides

The adsorbable organic halides referred to here include the following substances:

a. Halogenated organic carriers (dichlorobenzene, trichlorobenzene, pentachlorobenzene, hexachlorobenzene, monochlorotoluene, dichlorotoluene, trichlorotoluene, etc.)

b. Chlorinated hydrocarbon solvents (1,1, 1-trichloroethane,1, 2-dichloroethane,1, 1-dichloroethylene, trichloroethylene,1, 3-dichloropropylene, etc.)

c. Halogenated finishing agents (halogenated flame retardants such as phosphoric acid [tri (2, 3-dibromopropyl)] ester, namely TDPBB, decabromodiphenyl ether, namely flame retardant ZR-10, etc., anti-shrinkage finishing agents such as wool anti-shrinkage finishing agents, etc., mothproofing agents such as Mitin FF, mothproofing agent N, halogenated insecticides such as dichlorodiphenyltrichloroethane, DDT, etc., preservatives such as pentachlorophenol, etc., halogenated fungicides such as 5,5 '-dichloro2,2' -dihydroxydiphenylmethane, bactericide, etc.)

d. halogenated pretreatment agents (chlorine-containing bleach, such as hypochlorite, etc., scouring agents, such as chlorofluoroolefin solvents, etc.)

8, does not contain other harmful chemicals

Other hazardous chemicals include phosphates, ethylenediamine tetraacetic acid, diethylenetriamine pentaacetic acid, volatile organic compounds, and restricted pesticides.