**Part 3**

**Surface Modification** 

108 Natural Dyes

It is assumed that insoluble dyestuff is reduced to leuco compound by the high reductivity of the phenyl phosphinic acid in the phosphorous flame retardant 2, 6) as shown in Figure 5.

reduction

oxidation

In this chapter, the flame retardancies with deluster contents and dyeing fastnesses with

Whereas titanium dioxide as the deluster affects the flame retardancy of the polyester, it does not affect the dyeing fastness. Titanium dioxide is semi conductor material whose band gap is 3.2eV. Titanium compound in polyester fiber is activated by light, so polyester fibers containing titanium dioxide has color shading problem(yellowing) for outdoor usage. To minimize the yellowing of the polyester goods of polyester fiber with titanium dioxide, phosphorous stabilizer was used. So it could be thought that a part of phosphorous compound act as the stabilizer to reduce the activity of titanium dioxide and the remnant

Low level of light fastness of phosphorous flame retardant polyester fiber is due to reductivity of the phosphorous compound. The phosphorous compound shows acidity by the nature of phenyl phosphinic acid to fade out the disperse dye. Light fastness of the phosphorous flame retardant polyester can be minimized by benzotriazole stabilizer5. In commercial scale, it is a proper way to improve of light fastness of Flame retardant polyester

[5] D.M.Nunn, *The dyeing of synthetic-polymer and acetate fibres*, pp.10~12, London, Dyers

[6] K. Madhusudan Reddy et al.(2002), *Materials Chemistry and Physics*, Vol.78, pp. 239–245 [8] L. Kor¨osi, I. D´ek´any (2006), *Colloids and Surfaces A: Physicochem. Eng. Aspects,* Vol. 280,

[1] S.C.Yang; J.P.Kim(2007). *J. Appl. Polym. Sci*., Vol.106, No.5, pp.2870-2874 [2] S.C.Yang; J.P.Kim(2007). *J. Appl. Polym. Sci*., Vol.108, No.2, pp.1274-1280 [3] S.C.Yang; J.P.Kim(2008). *J. Appl. Polym. Sci*., Vol.108, No.4, pp.2297-2300 [4] M.Gratzel(1997), *Studies in Surface Science and Catalysis*, Vol.103, pp.353-375

Company Publications Trust(1979)

[10] S.G.Park, *in Seminar Handout*, 13th. Nov. 2001.

O-

O-

O

O

phosphorous contents were investigated.

reveals the flame retardancy.

pp. 146–154 [9] S.C.Yang, et al., WO 2006/070969

**3. Conclusion** 

fiber.

**4. References** 

Fig. 5. The brief scheme of reduction state of anthraquinone dyestuff

**7** 

**Protein Fibre Surface Modification** 

*4Riddet Institute at Massey University, Palmerston North,* 

*3Biomolecular Interaction Centre, University of Canterbury, Christchurch,* 

Many natural fibres, including wool, cashmere and silk, are protein-based materials; the dry weight of wool is almost entirely derived from proteins (Maclaren & Milligan 1981). As such, they possess an inherent structural and chemical heterogeneity not found in synthetic polymers. Although typically less heterogeneous than biological fibres, the rapidly emerging range of commercially available protein-based biomaterials also contain a wide range of

The response of fibres to processes such as dyeing and finishing treatments correlates directly to their structural and chemical properties, and this is particularly true for surface treatments. Due to its barrier function in the fibre, modification of the surface has a profound impact on processing and performance. Keratinous fibres such as wool and cashmere have an outer lipid layer which results in a hydrophobic surface. Recently a range of innovative and novel fibre surface technologies has been developed, many of which involve altering surface properties by the removal of the lipid layer, which exposes a proteinaceous surface with a variety of reactive chemical moieties. Treatments that can be covalently bound to fibre surface components, rather than simply physically applied to the

The surface modification of proteinaceous fibres has a long history. These include plasma applications, which expose and generate functional groups on the protein surface, etching into the surface of the cuticle scales, to improve properties such as surface wettability, dyeability, shrink-resistance and felting-resistance. Chemical approaches utilised include ozone treatments, which cause oxidation of the surface and altered ionic balance, leading to a more plastic and reactive fibre surface and shrinkage control; chlorination, which improves sorption characteristics and reduces shrinkage; hydrogen peroxide treatment; and acid anhydride acetylation of silk and wool, which improves the textile response to dyeing, shrink resist, and setting treatments. Enzymatic treatments have been utilised to decuticulate the surface and improve properties such as shrink resistance. More recent developments include reaction of functional chemical agents or branched molecules to exposed reactive groups on the fibre surface, enabling the attachment of covalently-bound

smart treatments, or the amplification of reactive groups for increased functionality.

This chapter outlines developments in the area of targeted surface modification of proteinbased fibres and textiles, including summarising applications and future directions. It is not

functionality derived from their constituent primary and secondary protein structure.

surface, offer the potential for superior durability.

**1. Introduction** 

 Jolon Dyer1,2,3,4 and Anita Grosvenor1 *1AgResearch Lincoln Research Centre, Christchurch,* 

*2Lincoln University, Canterbury,* 

*New Zealand* 
