Cyanoethylation of several fiber materials and their utilization as adhesive in wood-based panels
This study examines the cyanoethylation and thermoplasticity of several cyanoethylated fiber materials. Cyanoethylated pulps with a degree of substitution of 1.43 have the lowest Vicat softening point. Cyanoethylated poplar with a weight gain of 18.2 % has the lowest melting temperature. Instead of traditional adhesives, cyanoethylated materials can be used to produce wood-based panels because of their good thermoplasticity. Plywood bonded with cyanoethylated pulp has a bonding strength of 2.06 MPa and an average wood failure of 62.7 %. Wheat straw particle board containing 40 % cyanoethylated pulp has an internal bonding strength of 0.49 MPa, a modulus of rupture (MOR) of 33 MPa, and a density between 0.5 and 0.6 g cm−3. Fiberboard containing 40 % cyanoethylated pulp has an internal bonding strength of 0.53 MPa, MOR of 38 MPa, modulus of elasticity of 4,200 MPa, and a density between 0.7 and 0.8 g cm−3. Its swelling in thickness is 41 %.
Thermoplastic composites from cyanoethylated wood and high density polyethylene
Cyanoethylated cellulose samples of different degrees of substitution (or nitrogen content) have been prepared and intrinsic viscosity has been measured which shows that cellulose undergoes no appreciable fall in molecular weight by this reaction. Powdered rubber wood (Hevea Brasiliensis) has been cyanoethylated in the same way as cellulose and the product (CRW) blended with HDPE both without and with maleic anhydride-grafted-HDPE as compatibilizer. Measurement of impact properties reveals that the use of a compatibilizer significantly increases the dispersion of CRW particles in the HDPE matrix and promotes ductile fracture and higher impact strength, while the effects of notrogen content of CRW on these properties are only marginal.
Thermal Analysis of Lignocellulosic Materials. Part II. Modified Materials
Abstract Thermal analysis is a group of techniques in which a physical property of a substance is measured as a function of temperature while the substance is subjected to a controlled temperature program. The output of thermal analysis represents data predominantly in the form of curves characteristic for a particular chemical substance or a mixture of substances. Changes in latent heat in a chemical substance are detectable by differential thermal analysis (DTA) or by differential scanning calorimetry (DSC). Progressive weight loss is detectable by thermogravimetry (TG) or differential thermogravimetry (DTG). Progressive changes in certain mechanical properties are detectable by thermomechanical analysis (TMA). Many other thermoanalytical techniques are available, but are used appreciably less often.