Preparation, Properties And Application Of Rosin Modified Polyacrylamide

Rosin is one of important forest products in China,and the key issue is how to use it for deep processing.In this work,the polyacrylamide was modified by rosin-based derivatives,and then,the influence of rosin on the properties of the materials was investigated.The water-soluble polymerizable monomer diallylmethyl dehydroabietic acid propyl ester ammonium bromide?DMDHAE?was synthesized from dehydroabietic acid and used to prepare hydrophobically modified cationic polyacrylamide?HMPAM?.The salt tolerance,shear resistance and apparent viscosity of HMPAM were improved,and the flocculation performance of kaolin was studied.The rosin cross-linked polyacrylamide hydrogel?RPAM hydrogel?with high mechanical properties was prepared by the micellar copolymerization of rosin-based crosslinker FPA-PEG200-AC and acrylamide,and the drug release properties of the RPAM hydrogel were also discussed.The conclusions are as follows:The DMDHAE was prepared by the esterification and quaternization of dehydroabietic acid,3-bromopropanol and methyldiallylamine.The monomer purity is 89%,melting point is 127¹31 ^?,and solubility is 150 g/dL.The polymerization parameter was measured by differential scanning calorimeter?DSC?,and bulk polymerization kinetics was analyzed with autocatalytic model.The results showed that the activation energy?E_a?is 124.34 KJ/mol,and kinetic equation was obtained.A series of hydrophobically modified cationic polyacrylamide?HMPAM,such as HMPAM-0.5,HMPAM-1.0,HMPAM-1.5 and HMPAM-2.0?were synthesized from DMDHAE.The preparation process was optimized and the HMPAM solution performance was studied.the optimum conditions for preparation of HMPAM were that the amount of initiator,monomer concentration and the amount of DMDAAC were 0.075 wt%of total monomer mass,20 wt%and 18 mol%of total monomer molar mass,respectively;the critical association concentration?CAC?of HMPAM aqueous solution was about 0.7 wt%,HMPAM solutions exhibited a strong hydrophobic association when the concentraton of HMAM solutions was above CAC,and the apparent viscosity of HMPAM solutions increased sharply.The apparent viscosities of HMPAM dramatically increased with the increase in NaCl or CaCl₂concentrations.The apparent viscosity of HMPAM solutions increased with the shear rate rising at low shear rates.However,a sharply reduced in apparent viscosity accompanied the shear rate increasing,and HMPAM solutions exhibited significant pseudoplasticity.Compared with CPAM,the apparent viscosity and salt resistance of HMPAM aqueous solutions were greatly improved due to the formation of hydrophobic association between rosin groups.The flocculation performances of HMPAM were investigated.The flocculation performance was reduced with the content of DMDHAE increased.HMPAM-0.5 showed excellent flocculation performance in kaolin suspensions with concentration of 3⁵ wt%,and the supernatants were above95%.HMPAM exhibited good flocculation performance in acidic conditions,and the settlement rates initially reduced and subsequently increased with the increase in pH.The flocculation performance of HMPAM was also significantly improved with the addition of NaCl and CaCl₂,the settlement rates of all copolymers increased with the addition of NaCl and CaCl₂.HMPAM showed excellent flocculation performance in wide concentration gradients and high salt content kaolin suspensions.The rosin-based crosslinking agent FPA-PEG200-AC was synthesized from fumaropimaric acid.The series of RPAM hydrogels?RPAM-1.5,RPAM-2.0,RPAM-2.5,RPAM-3.0 and RPAM-3.5?were prepared from acrylamide and FPA–PEG200–AC via micellar copolymerization,and the swelling and mechanical properties were investigated.The swelling ratio of RPAM hydrogels increased first and then decreased with the rise in time,and decreased with the increase of FPA-PEG200-AC.The surface morphology of RPAM hydrogels was affected by the dosage of rosin-based cross-linking agent FPA-PEG200-AC and the structure of RPAM-2.5 hydrogel was the most regular.The hydrogel with rosin group showed excellent mechanical properties.The RPAM hydrogels exhibited high tensile properties and the stress-strain curves exhibited nonlinear,the maximum elongation at break of RPAM-1.5 hydrogel was 1500%.RPAM hydrogels can withstand compression strain?>95%?and quick recovery.The drug release properties of rosin-based polyacrylamide hydrogels were investigated.The results indicated that the equilibrium swelling ratios of hydrogels decrease with the increase of the amount of the FPA-PEG200-AC,which is the largest in the pH 7.4 PBS buffer,followed by the deionized water and the smallest in the pH 1.4 hydrochloric acid solution;diclofenac sodium was mainly released within 1 h,reaching the maximum values of cumulative release within 3 h.ciprofloxacin was released slowly and reached the maximum values of cumulative release within 8 h;the maximum cumulative release of RPAM-2.5 hydrogel was about 99%,and for other hydrogels,the maximum values of cumulative release decreased as the drug loading ratio decreased.The maximum values of theophylline at pH 7.4 PBS buffer can reach 99%,which is higher than the cumulative release rate in hydrochloric acid solution at pH1.4.The release kinetics of RPAM hydrogels was studied.The drug release of RPAM-2.0 hydrogel and RPAM-3.0 hydrogel was Higuchi models.The ciprofloxacin release in RPAM-1.5 hydrogel and RPAM-3.5 hydrogel,diclofenac sodium release in RPAM-3.5 hydrogel,theophylline release in RPAM-2.5 hydroggels?pH 7.4 PBS buffer?and theophylline release in RPAM-2.5 hydrogel and RPAM-3.5 hydrogels?pH1.4 HCl solution?were Korsmeyr-Peppas models,the diffusional exponent n<0.5,Fick diffusion.