Several approaches to the modification of cellulose fibres are described, namely: (i) physical treatments such as corona or plasma treatments under different atmospheres; (ii) grafting with hydrophobic molecules using well-known sizing compounds; (iii) grafting with bi-functional molecules, leaving one of the functions available for further exploitation; and (iv) grafting with organometallic compounds. The modified surfaces were characterized by elemental analysis, contact angle measurements, inverse gas chromatography, X-ray photoelectron and infrared spectroscopy, wettability, etc. These different tools provided clear-cut evidence of the occurrence of chemical reactions between the grafting agent used and the hydroxy functions of the cellulose surface, as well as of the existence of covalent bonding in the ensuing composite materials between the matrix and the fibres through the use of doubly reactive coupling agents.

ABSTRACT In this research it was analyzed the possibility of producing handmade papers with good properties from mixtures of recycled fibers with kraft pulps of bamboo (Dendrocalamus giganteus) and sugar-cane bagasse (Saccharum officinarum). Handmade papers with higher folding endurance and tear strength were produced with the mixtures whose compositions had 20 % or more of sugar-cane bagasse pulp. Papers with higher smoothness and burst strenght were obtained from mixture of 80 % of waste paper mass and 20 % of bagasse pulp. It was observed that mainly the bagasse pulp can be used to improve the properties of the handmade paper.

RESUMO Neste trabalho analisou-se a possibilidade de se produzir papéis artesanais com boas propriedades, das misturas de massa de aparas com as pastas kraft de bambu (Dendrocalamus giganteus) e de bagaço de cana-de-açúcar (Saccharum officinarum). Papéis com as maiores resistências à dobragem e ao rasgamento foram obtidos das misturas com 20 % ou mais de pasta de bagaço. Maiores lisuras e resistência ao arrebentamento foram obtidas do consorciamento de 80 % da massa de aparas e 20 % de pasta de bagaço. Concluiu-se que principalmente a pasta do bagaço da cana-de-açúcar pode ser utilizada para melhorar as propriedades do papel artesanal.