Antimicrobial and insect-resist wool fabrics by coating with microencapsulated antimicrobial and insect-resist agents

In this work, various types of antimicrobial and insect-resist agents were microencapsulated by several techniques to minimise their toxicity to humans. The microencapsulated antimicrobial and insect-resist agents were applied to wool fabrics by a pad-dry-bake method, and their performance was assessed in accordance with standard methods. The durability of the treatments to ageing and washing was evaluated. It was found that the antimicrobial and insect resist agents migrated to the outer surface of the capsules during ageing. Of the antimicrobial agents investigated, poly(N,N-dimethyl-2-hydroxypropylammonium) chloride or Barquat PQ 2 encapsulated with polylactic acid showed the best overall antibacterial performance after 10 cycles of International Wool Secretariat (IWS) 7A washing and also after ageing. The clothianidin insecticide encapsulated with polylactic acid showed the best insect-resist performance according to Wools of New Zealand Test Method 25 at a level of 50 ppm, passing this test method even after 10 cycles of washing. The washed fabric showed 85% insect mortality and the mean wool mass loss was only 4.6 mg. The fabric handle properties were only slightly affected by the treatments. The developed methods may find application in industry as they are quite durable to washing.