Study On Synthesis And Strength Of Amphoteric Polyacrylamide

Total imports of waste paper had dropped sharply because that waste paper was banned to import into China since 2017.The policy of import continue to strained.So,total approval and imports of waste paper could continue to decline.The domestic waste resources will become more and more important.How to improve the strength of secondary fiber is one of the most important research subject.This is the only way to improve competitiveness of papermaking industry.Therefore strengthening agent was used to improve the paper quality in the process of waste paper papermaking.Firstly,acrylic,diallyl dimethyl ammonium chloride and acrylamide were used as the main raw material.Amphoteric polyacrylamide was synthesized by the way of solution polymerization.Synthesis conditions such as monomer concentration,monomer ratio,initiator dosage,reaction temperature,reaction time were studied.The best results are as follows: the concentration of monomer was 20%,the monomer ratio of acrylic acid and acrylamide was 1:10,the ratio of acrylamide and DADMAC was 2.28,the initiator concentration was 0.2%;Reaction temperature was around 60°C,Reaction time was 2.0 to 2.5 h.The molecular weight of poly propylene amide could reach up to 500000.This condition was used as the best preparation technology.Secondly,strengthening performance of polyacrylamide was studied in the paper.Amphoteric polyacrylamide and laboratory preparation of cationic polyacrylamide and commercially available polyacrylamide were chosen to analyze strengthening performance.Burst strength,tensile strength,tearing strength,folding,ring crush strength and other physical strength were determined.Results show that with the increase of dosage of strengthening agent,the physical strength of paper canincrease to a certain extent,when the adding quantity is 3 ‰.Enhancement effect has no obvious improvement when increasing the quantity of strengthening agents.