Effect Of High Temperature Heat Treatment On The Performance Of Calamus Simplicifolius

Heat treatment technology is a kind of environment friendly physical modification technology,which can improve the surface color,dimensional stability and durability of the material,and improve the quality of the product.Palm rattan is the mostimportant non-timber forest product after wood and bamboo.The heat treatment of rattan is close to the blank.Therefore,the material properties of rattan cane after steam heat treatment are thoroughly studied.It can improve the stability of rattan cane,endow the rattan with good color decoration performance,thus improve the utilization ratio of rattan cane and expand the use range of rattan cane species and rattan products.In this paper,Calamus simplicifolius was modified by steam heat treatment technology ?temperature 160?,180?,200?;duration 2h,4h?.The surface properties,physical and mechanical properties,chemical properties and thermal stability of the heat-treated cane were analyzed.Based on the analysis of chemical composition,crystallinity and infrared spectrum,the mechanism of steam heat treatment on the perf-ormance of Calamus simplicifolius cane was analyzed.The main results were as follows:1.After heat treatment,the color of the cane was deepened.With the increase of heat treatment temperature and the prolongation of heat treatment time,the brightness L^*and the yellow and blue color index b^*of Calamus simplicifolius showed a downward trend,while the red and green color index a^*showed a first increase and then decrease,the critical temperature of the change was 180?,and the time was 2?4h.With the increase of heat treatment temperature and the prolongation of heat treatment time,the total chromatic aberration?E^*of rattan cane presented the rising trend,the change of lightness was the main reason that affects the overall chromatic aberration,and the lightness L^*was significantly negatively correlated with the total chromatic aberration?E^*.Heat treatment has a significant effect on wettability of Calamus simplicifolius cane.With the increase of heat treatment temperature,the contact Angle of the cane wac increased,thus reduced its wettability.2.With the increase of heat treatment temperature and the extension of treatment time,the basic density,dry shrinkage and water absorption of Calamus simplicifolius cane showed a decreasing trend.The heat treatment temperature had a significant influence on the physical properties except the cross sectional area dry shrinkage and radial dry shrinkage.The critical temperature of heat treatment for various physical properties was180?,and the critical heat treatment time was 2h.With the increase of heat treatment temperature and the prolongation of treatment time,the elastic modulus,flexural strength and compressive strength of Calamus simplicifolius cane firstly increased and then decreased.The critical change temperature of the elastic modulus and compressive strength was 180?,the time was 2?4h,the changing temperature of the bending strength was 160?,and the significant change time of the compressive strength is 2h.The increase of heat treatment temperature and the prolongation of treatment time reduced the impact toughness of Calamus simplicifolius,and the flexibility firstly decreased and then increased.The impact toughness decreased significantly when the temperature was higher than 180?,however the flexibility increased significantly.3.With the increase of heat treatment temperature and time,the weightlessness rate of rattan increased gradually,and the weightlessness rate increased to 15.03%at 200?and4h.The heat treatment time and temperature had a significant effect on the weight loss rate of rattan.Compared with the untreated cane,the heat treatment temperature with significant difference was 160?and theheat treatment time was 2h.4.The content of holocellulose and cellulose in rattan was decreased with the increase of heat treatment temperature and heat treatment time,while the content of lignin and benzene-alcohol extract was increased.Heat treatment temperature and time had a significant effect on the content of rattan components.The temperature of the holocellulose content changed significantly at 180?,the temperature which changed significantly of cellulose,and lignin and benzene-alcohol extract was 160?,and the time was 2h.There was a significant linear correlation between the brightness difference,the total color difference and the difference value of its content.There was a significant correlation between the mechanical properties of the heat treated material and the chemical composition,the change of holocellulose content was the main reason for the change of bending modulus of elasticity,holocellulose and cellulose were the main factors affecting the impact toughness.The results of FT-IR analysis showed that the absorption strength of the corresponding O-H peak of 3427cm^-1,the corresponding C=O peak of 1736cm^-1 and the C-H peak corresponding to 1375cm^-1 was decreased during the heat treatment process,and the corresponding C-O peak 1234cm^-1 absorption strength was increased.These changes were consistent with the results of chemical composition.5.When the heat treatment temperature was lower than 200,the pectin could not be removed.The corresponding temperature of the maximum mass loss rate of rattan increased with the increase of heat treatment temperature and the prolongation of treatment time,so the thermal stability of the heat treated rattan was improved.6.The crystallinity of Calamus simplicifolius increased with the increase of heat treatment temperature and the prolongation of treatment time,at 200?and 2h,it reached the maximum value,which was 44.2%higher than that of untreated cane.The heat treatment time and temperature had a significant effect on the crystallinity of the rattan.The significant change temperature was 180?,and the significant change time was 2?4h.At the 0.05 level,the crystallinity of treated cane had a significant correlation with the impact toughness.