Eco-affable natural colorant and their scope
Prasoon Kumar Kaushik , Research Scholar, Chemistry Division, Forest Research Institute, Dehra Dun – 248 006
With the increasingly concern over environmental issues, textile industries are now interested in natural dyes. In recent years, the demand of natural dyes in textile, food processing, cosmetic and pharmaceutical industries has been rapidly increased all over the world due to eco-affable nature. However, the technology of extracting and utilizing natural dyes in the modern textile industry is relatively new and is still being improved upon. In India, textile manufacturers are not yet finding proper enticement in switching over to natural dyes for being more expensive than their synthetic counterparts.
In India, most rural people use forest products and many obtain part of their income from forest-based activities. For instance, collection of tendu leaves provides part-time employment to about 7.5 million people. A further 3 million people are employed in bidi processing and another 3 million people are involved in lac (resin) production. About 0.75 million earn income from sericulture; about 0.55 million people are employed in bamboo-based craft enterprises and about 0.13 million households are involved in tassar silk cultivation. The dyeing with natural colourants has one of another oldest techniques practiced by the ancient civilization people as a source of income.
The invention of the first synthetic dyes by William Henry Perkin in 1856 changed the situation and later, the synthetic dyes received faster acceptability due to a wide range of applications in various fields like food, cosmetic, photodynamic therapy, non-linear optical activity and more importantly in textile industries due to ease in dyeing, and overall cost factor. But, during the last few decades, the use of synthetic dyes is gradually decreasing due to an increased environmental awareness and harmful effects because of either toxicity or their non-biodegradable nature. In addition to above, some serious health hazards like allergic and, carcinogenicity are associated with the synthetic dyes. As a result, recently a ban has been imposed all over the world including European Economic Community (EEC), Germany, USA and India on the use of some synthetic dyes.
India is richly endowed with vast variety of natural flora. It is estimated that, in India there are some 500 varieties of plants that can yield natural colours the art and craft of producing natural dyed textile is being practiced in many villages by expert’s craftsmen in the country. In view of this, it was thought worthwhile to explore the renewable source for producing of natural dyes from abundantly occurring and easily available forest biomass.
P. roxburghii needles are available in plenty and considered hitherto as waste materials thus chosen for the study. The Pine needles contain a substance called terpene, this is released when rain washes over the needles and it has a negative effect on the germination of some plants, including wheat. The present research work was taken for make a trouble-free way for utilization of waste materials for the preparation of dye for different fabrics. This work was covered to parametric optimization for optimal recovery of dyes from P. Roxburghii Needles then applied on different fabrics.
P. roxburghii (known as chir pine) is a species of pine native to the Himalayas, and named after William Roxburgh. The range extends from northern Pakistan, across northern India (Jammu and Kashmir, Punjab, Himachal Pradesh, Uttarakhand, Sikkim) and Nepal to Bhutan. It generally occurs at lower altitudes than other pines in the Himalaya, from 500–2,000 metres (1,600–6,600 ft), occasionally up to 2,300 m (7,500 ft). The other Himalayan pines are P. wallichiana (blue pine), P. bhutanica (Bhutan white pine), P. armandii (Chinese white pine), P. gerardiana (Chilgoza pine) and P. densata (Sikang pine). P. roxburghii is a large tree reaching 30–50 m (98–160 ft) with a trunk diameter of up to 2 m (6.6 ft), exceptionally 3 m (10 ft). The bark is red-brown, thick and deeply fissured at the base of the trunk, thinner and flaky in the upper crown. The leaves are needle-like, in fascicles of three, very slender, 20–35 cm (7.9–14 in) long and distinctly yellowish green.
P. roxburghii is an evergreen tree; wood is used for construction, poles, timber and furniture. Oleo-resins are present in the tissues of the all species of pines is used in varnishes, paint and turpentine. Extracts of P. roxburghii exhibited strong antibacterial, antiseptic, diuretic, rubefacient and vermifuge activity. It is very beneficial in respiratory complaints such as burning of the body, fainting, ulcers, coughs, colds, influenza, TB, useful also in treating diseases of the mucous membranes. Grieve, M. 1984 also reparted importence of P. roxburghii for skin complaints, wounds, sores, burns, boils etc and is used in the form of liniment plasters, poultices, herbal steam baths and inhalers.
The proportion of rosin and turpentine oil in chir pine is reported 75-90% and 22-25% respectively with 3% losses, etc. India imports resin which is far superior in quality as well as cheaper than the indigenous one. Literature survey revealed that pine needles yield essential oil (0.26%) which consists of alpha, beta-pinene, omega3 carene, alpha-limonene, borneol, borneol acetate, longifolene and a-cadinene. It has been recently reported by Kim Y. S. and Bae S. E. in 2013, that some flavonoids (figure: 1) in Pine bark are responsible for Brown colour.
Figure: 1 Chemical structure of (a) Taxifolin (b) Epicatechin (c) Procyanidin
Several studies in the last 10 to 20 years have characterized and promoted the use of natural dyes from different plant species, partly because of recent scientific developments in instrumental methods of colour measurements, analysis and structure determination consequently, many potential dye-yielding plants and major dye components have been identified through colourimetric and spectroscopic investigations.