Study On Mechanism Of Self-plasticized Bamboo Biomass

Bamboo is a fast-growing renewable resource,but there is a serious waste of resources caused by the low utilization rate.Ingredients,functional groups,shapes and existence patterns of wood extractives play a barrier role on wood permeability.There is a similarity between bamboo and wood in the cell wall structure and machining properties,can being shared on a number of processing technologies.Therefore,study the the combined effect of the extractives on bamboo cell walls plasticizing.Revealing the molecular bonding mechanism in the process of bamboo cell walls self-plasticizing.This study will address the serious constraints of bamboo processing and utilization of high quality and high efficiency in the field of technology to achieve significant theoretical breakthrough.While providing technical support for maximization of bamboo resources.Through nearly a three-year study,getting a lot of useful researching results,as follows:The better extracting time for bambooextraction,8h(benzene/alcohol extraction),8h(ethanol extraction),6h(ethyl acetate extraction),and stripping in multistage extractive rate of total is greater than a single extract dissolution rate.Thus the continuous chain of organic solvent extraction could trigger dissolution of bamboo extracts and bamboo cell wall are more purification.Bamboo extract by GC-MS analysis,it was found that there are 45 compounds in benzene/alcohol extract,mainly 2,3-glycol butyl(20.11%),palmitic acid(7.66%),linoleic acid(7.15%)and so on.Ethanol extracts contain 27 kinds of compound,mainly 2,3-glycol butyl(14.69%),4-((1E)-3-Hydroxyl-1-Allyl group)-2-Methoxyphenol(9.75%),2,3-Dihydrobenzofuran(9.29%)and so on.There are 54 kinds of compoud in ethyl acetate extracts,and main components are 4-((1E)-3-hydroxyl-1-Allyl group)-2-methoxypheno(17.02%),2,3-Dihydrobenzofuran(16.26%)and so on.When extracting by benzene/alcohol solution,the remaining time of bamboo extractives focusing on 30-40min,relative content 22.35%,the retention time of 20.71%composition less than 10 min,the retention time of 14.31%composition higher than 50 min.When the ethanol extraction,the remaining time of 55.46%bamboo extractives less than 40min,the retention time of 4.87%composition higher than 50 min.When extracting by ethyl acetate solution,the remaining time of bamboo extractives focusing on 10-20min and 20-30min,respectively 20.74%and 20.48%.The effect of forming temperature on bonding strength of the self-plastisizing samples is also significant.The effect of briquetting pressure on the bonding strength of the self-plastisizing samples is more visible,but the effect of holding time is not obvious.After extracting,the bonding strength of bamboo self-plastisizing samples is more than no extraction of bamboo self-plastisizing samples.During the process of bamboo self-plastisizing,bamboo extracts has the interference effect.The better self-plastification technology:the forming temperature 170?,the briquetting pressure 11 MPa,the holding time 40min.The jamming role bamboo extracts on cell wall of self-plastisizing mainly in three aspects,firstly,bamboo cellulose,hemicellulose and lignin degradation under the action of high temperatures and pressure,the generated in the plasticizing process is similar to the"adhesive" new stable polymer and it make the bamboo cell wall bond to achieve itself combination.But there is the bonding reaction between bamboo extract and bamboo cell wall composition and it hinders the main components of bamboo cell wall bonding.Removal of bamboo extracts can promotes the bonding of bamboo cell wall composition in self-plastisizing.Secondly,after bamboo extracting,the bonding strength of self-plastisizing samples greater,crystal greater,so removal of bamboo is good for bamboo cellulose crystallization.Thirdly,the extract deposits outside and inside the cell lumen surface,reducing chance exposed of active groups of the main components in bamboo cell wall,lowering bamboo cellulose,hemicellulose,lignin bonding probability,resulting in self-adhesion reduces,making extracts interfere with bamboo cell wall bonding.Infrared spectrum and nuclear magnetic resonance spectra show that,before and after self-plastisizing,bamboo cellulose,cellulose and lignin,cellulose fiber complex hydrogen radical,methyl,methylene,benzene ring and other characteristic groups change obviously.Thus confirming that cellulose,hemicellulose,lignin in self-plastisizing,bridged chemical reactions such as esterification,etherification,have a key role towards combination between bamboo cell wall.After the self-plastisizing,the crystallinity of bamboo cellulose,cellulose-lignin complexes,complexes of cellulose enhance respectively 5.8%,2.28%,11.67%,and in the self-plastisizing,bamboo cellulose,cellulose,and lignin characteristics peak change regularly,have a bonding effect.The weight loss rate of the bamboo self-plastisizing samples after extraction is less than no extraction bamboo samples.It account for that a plastics-processing can improve the chemical combination level of fiber,cellulose-lignin composite.Thus,preparing lignin cellulose or cellulose composite for self-plastisizing material is appropriate.