Development background and evaluation of waterproofing agent

Waterproofing agents can be divided into two categories based on their carbon chain structure, one is fluorinated waterproofing agents, and the other is fluorine-free waterproofing agents. Currently, the most commonly used fluorinated waterproofing agents are carbon eight waterproofing agents and carbon six waterproofing agents.

Carbon eight waterproof agent, also known as perfluoroalkyl compound, C&flash; The F bond has high bond energy, small spacing, and low polarization, making it very stable. It has extremely low surface tension in aqueous solutions and excellent hydrophobicity and hydrophobicity. Under the influence of comprehensive environmental conditions, perfluoroalkyl compounds will gradually degrade into long-chain perfluoroalkyl acids over time, ultimately metabolizing into perfluorocarbonic acids (PFCA), among which perfluorooctanoic acid (PFOA) is a typical representative. PFOA has strong persistence and is currently one of the most difficult organic pollutants to decompose. The condition for its decomposition is high-temperature incineration. Due to its strong bioaccumulation and carcinogenic risk, its use is widely restricted.

Carbon six waterproofing agent was developed after carbon eight waterproofing agent, which is synthesized from six carbon fluorinated acrylic resin. It meets the environmental requirements specified in OEKO-TEX Standard 100, which states that the PFOA and PFOS content in fluorine based waterproofing agents must be less than 1ug/㎡. However, in 2021, the European Commission for Social and Economic Analysis (SEAC) passed a final opinion on Germany's proposal to limit perfluorohexanoic acid (PFHxA), its salts, and related substances. After the draft is approved, the control of PFHxA, its salts, and related substances will be officially included in the REACH regulatory restriction section, and it is expected that the ban will come into effect in mid-2025. At that time, C6 waterproofing agent will be banned, and only fluorine-free waterproofing agents or perfluorinated waterproofing agents with shorter carbon chains can be used.

In order to adhere to the sustainable development path of green peace, fluorine-free waterproofing agents will inevitably become the mainstream in the future. Due to the structure of fluorine-free waterproofing agents, their surface tension is relatively high and they have no anti oil effect. The current fluorine-free waterproofing agents cannot achieve the effect of fluorine-containing waterproofing agents, and the color change is also greater than that of fluorine-containing waterproofing agents. Therefore, developing more comprehensive and high-performance fluorine-free waterproofing agents, especially new polymers with lower surface tension, is currently a research direction for major companies. The main focus is on the modification of polyurethane and organic silicon, polyurethane and acrylic acid, acrylic acid and organic silicon, nano SiO2 modification, and modification of various superhydrophobic structures.

Common testing standards for waterproofing and oil resistance

Waterproof performance test	Spray testing	GB/T 47-2012	Testing and evaluation of textile waterproofing performance based on water immersion method
		ISO 4920-2012 (E)	Determination of surface moisture resistance of textiles (spray test)
		AATCC 22-2017	Water repellent spray test
		JIS L1092:2009	Test method for water resistance of textile fabrics
	Wetting resistance test	AATCC 193-2017	Wetting resistance: waterproof/ethanol solution
	Bondis Gate Test	GB/T 14577-1993	Determination of water repellency of fabrics - Bondsman rain method
		ISO 9865-1991（E）	Textile Bondsman rain test
		BS EN29865-1993
Waterproof performance test	Rain test	GB/T 23321-2009	Horizontal spray rain test for waterproofing of textiles
		ISO 22958-2021 (E)	Textile water resistance rain test: Horizontal spray method
		AATCC 35-2018	Waterproofing: Test to prevent rainwater penetration
	Water shock resistance test	GB/T 33732-2017	Determination of water permeability of textile fabrics - Impact penetration test
		ISO 18695-2007 (E)	Textile fabrics - Determination of water permeability - Permeability test
		AATCC 42-2017	Water repellency: impact water permeability test
	Water pressure resistance test	GB/T 4744-2013	Testing and evaluation of waterproof performance of textiles - Hydrostatic pressure method
		ISO 811-2018 (E)	Textiles - Determination of water permeability - Hydrostatic pressure test
		AATCC 127-2017	Water resistance: hydrostatic method
Oil repellent performance test		GB/T 19977-2014	Textiles - Oil repellency - Hydrocarbon resistance test
		ISO 14419-2010 (E)	Textiles - Oil repellency, hydrocarbon resistance test
		AA 130-2018TCC	Oil repellency and hydrocarbon resistance test
Anti fouling and easy decontamination performance test	Easy to decontaminate test	FZ/T 01118-2012	Testing and evaluation of anti fouling performance of textiles - Ease of decontamination
		AATCC 130-2018	Standard and method for easy decontamination testing
	Anti fouling test	GB/T 30159.1-2013	Testing and evaluation of textile anti fouling performance - Part 1: Staining resistance
Washable performance test		GB/T 8629-2017	Household washing and drying procedures for textile testing
		ISO 6330-2021 (E)	Household washing and drying procedures for textile testing
		AATCC 135-2018	Determination of dimensional changes in fabrics after home washing
		JIS L1930-2014	Household washing test method for textiles
		JIS L0217-1995	Notes and labels for textiles