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Two synthetic sizing agents based on polyvinyl alcohol (PVA) were prepared by direct radiation of acrylic acid (AA) or N-vinyl-2-pyrrolidone (VP) in the presence of predissolved PVA. The rheology, film resolubility and removability of these sizing agents were compared with those of PVA. It was found that (a) the flow behaviour of 10% aqueous solutions (at 80°C) of these materials is characterized by a non-Newtonian thixotropic property that shows a measurable shear thinning character, (b) the degree of thixotropy is arranged ascendingly according to the order PVA/PVP < PVA/PAA < PVA, (c) the solubility rate of PVA size films and size removability of these sizing agents (as a function of the nature of the size used) follow the decreasing order: PVA/PVP > PVA/PAA > PVA.

Cellulose pulps prepared from bagasse, rice straw, cotton stalk and wood sawdust were polymerized in the presence of acrylic acid(AA) and acrylonitrile(AN) with binary mixtures. Potassium persulphate was used as the initiating system. The treatment was carried out under different conditions including concentration of AA and AN, composition of AA/AN binary mixture, potassium persulphate concentration, material to liquor ratio, time and temperature of polymerization. Based on the results obtained, appropriate conditions for the preparation of vinyl polymer-cellulose composites were established. The maximum total conversion occurred at 0.5% K2S2O8along with 5% AA and 5% AN at 70°C for 60 minutes using a material-to-liquor ratio of 1:20. The treated samples were monitored for polymer yield, carboxyl and nitrogen contents as well as swellability and solubility. Results indicated that the total conversion (grafting and homopolymerization) increased by increasing K2S2O8concentration irrespective of the land of cellulose pulp used. Nevertheless the percent polymer yield and percent graft yield follow the order: > Bagasse > rice straw > cotton stalk ≥ wood sawdust. The nitrogen content is higher the higher the concentration of AN in the AA/AN binary mixtures regardless of the kind of agricultural waste. Carboxyl content is higher, the higher the concentration of AA in the AA/AN binary mixture. The swellability of the composite is governed by the composition of the AA/AN binary mixture and it is higher, the higher the concentration of AN in the AA/AN binary mixture irrespective of the kind of cellulose source, but with the certainty that swellability of the composites follows the order: Bagasse > rice straw > cotton stalk > wood sawdust. The solubility of the composite is also governed by the composition of AA/AN binary mixture and it is higher the higher the concentration of the AA in the mixture and follow the order: Rice straw ≥ wood sawdust > cotton stalk ≥ bagasse

Polymerisation of methacrylic acid (MAA) in the presence of cellulose pulps prepared from bagasse, rice, straw and cotton stalk was carried out under a variety of conditions. Potassium permanganate (KMnO4) was used as initiator, along with either citric acid or sodium thiosulphate (Na2S2O3) as activator. The polymerisation products, including grafted cellulose, homopolymer, ungrafted cellulose and oxidised cellulose in a polyblended form, is called “composite”. Major factors affecting the polymerisation reaction were studied. These encompass initiator, activator and monomer concentrations, duration and temperature of polymerisation as well as the nature of the cellulose substrate. Results for the percent polymer yield of the composite and those of the total conversion of monomer to polymer suggest appropriate conditions for the synthesis of poly (MAA)-cellulose composite as: [KMnO4], 0 08%; [Na2S2O3], 2.5 m.mole L; [MAA], 100% based on weight of sample; material to liquor ratio, 1:30; temperature, 70°C and time, 60 minutes. The effect of the nature of the cellulose on the properties and characteristics of the composite could be realised from the following orders:(1) for the polymer yield, graft yield and swellability: bagasse > rice straw > cotton stalk;(2) for carboxyl content: bagasse > cotton stalk > rice straw; (3) for solubility: rice straw > cotton stalk > bagasse.

Two synthetic sizing agents based on polyvinyl alcohol (PVA) were prepared by direct radiation of acrylic acid (AA) or N-vinyl-2-pyrrolidone (VP) in the presence of predissolved PVA. The rheology, film resolubility and removability of these sizing agents were compared with those of PVA. It was found that (a) the flow behaviour of 10% aqueous solutions (at 80°C) of these materials is characterized by a non-Newtonian thixotropic property that shows a measurable shear thinning character, (b) the degree of thixotropy is arranged ascendingly according to the order PVA/PVP < PVA/PAA < PVA, (c) the solubility rate of PVA size films and size removability of these sizing agents (as a function of the nature of the size used) follow the decreasing order: PVA/PVP > PVA/PAA > PVA.

Polymerisation of methacrylic acid (MAA) in the presence of cellulose pulps prepared from bagasse, rice, straw and cotton stalk was carried out under a variety of conditions. Potassium permanganate (KMnO4) was used as initiator, along with either citric acid or sodium thiosulphate (Na2S2O3) as activator. The polymerisation products, including grafted cellulose, homopolymer, ungrafted cellulose and oxidised cellulose in a polyblended form, is called “composite”. Major factors affecting the polymerisation reaction were studied. These encompass initiator, activator and monomer concentrations, duration and temperature of polymerisation as well as the nature of the cellulose substrate. Results for the percent polymer yield of the composite and those of the total conversion of monomer to polymer suggest appropriate conditions for the synthesis of poly (MAA)-cellulose composite as: [KMnO4], 0 08%; [Na2S2O3], 2.5 m.mole L; [MAA], 100% based on weight of sample; material to liquor ratio, 1:30; temperature, 70°C and time, 60 minutes. The effect of the nature of the cellulose on the properties and characteristics of the composite could be realised from the following orders:(1) for the polymer yield, graft yield and swellability: bagasse > rice straw > cotton stalk;(2) for carboxyl content: bagasse > cotton stalk > rice straw; (3) for solubility: rice straw > cotton stalk > bagasse.

Cellulose pulps prepared from bagasse, rice straw, cotton stalk and wood sawdust were polymerized in the presence of acrylic acid(AA) and acrylonitrile(AN) with binary mixtures. Potassium persulphate was used as the initiating system. The treatment was carried out under different conditions including concentration of AA and AN, composition of AA/AN binary mixture, potassium persulphate concentration, material to liquor ratio, time and temperature of polymerization. Based on the results obtained, appropriate conditions for the preparation of vinyl polymer-cellulose composites were established. The maximum total conversion occurred at 0.5% K2S2O8along with 5% AA and 5% AN at 70°C for 60 minutes using a material-to-liquor ratio of 1:20. The treated samples were monitored for polymer yield, carboxyl and nitrogen contents as well as swellability and solubility. Results indicated that the total conversion (grafting and homopolymerization) increased by increasing K2S2O8concentration irrespective of the land of cellulose pulp used. Nevertheless the percent polymer yield and percent graft yield follow the order: > Bagasse > rice straw > cotton stalk ≥ wood sawdust. The nitrogen content is higher the higher the concentration of AN in the AA/AN binary mixtures regardless of the kind of agricultural waste. Carboxyl content is higher, the higher the concentration of AA in the AA/AN binary mixture. The swellability of the composite is governed by the composition of the AA/AN binary mixture and it is higher, the higher the concentration of AN in the AA/AN binary mixture irrespective of the kind of cellulose source, but with the certainty that swellability of the composites follows the order: Bagasse > rice straw > cotton stalk > wood sawdust. The solubility of the composite is also governed by the composition of AA/AN binary mixture and it is higher the higher the concentration of the AA in the mixture and follow the order: Rice straw ≥ wood sawdust > cotton stalk ≥ bagasse