| Seeking alternative petrochemical resources of renewable resources for the manufacture of polymer materials is receiving a great deal of attention in the age of depleting fossil oil reserves and environmental wareness.Rosin,an abundant,low cost,and excellent performance renewable resource,has been engineered into renewable polymers having properties similar to petroleum-based polymers.In this work,in order to high-value utilize rosin,rosin or derivatives were used as raw materials to prepare rosin-based monomer by esterification,and then to prepared rosin-based homopolymer,rosin-based block copolymer and rosin-based biodegradable graft copolymer by reversible addition-fragmentation chain transfer(RAFT)polymerization and ring-opening polymerization(ROP),and miniemulsion polymerization,respectively..1.Rosin derived monomer blend was synthesized sequentially by chloridization and esterification,and characterized by GC/MS,1H NMR,13 C NMR.Rosin derived monomer blend,reversible addition-fragmentation chain transfer(RAFT)agent CDB and initiator AIBN with molar ratio 100:1:0.1 was then used to perform RAFT polymerization.In order to further investigate the RAFT polymerization of rosin derived monomer blend,high purity dehydroabietic acid derived monomer was also employed to perform RAFT polymerization.The results showed thatdehydroabietic acid derived monomer accounted for 14.3 wt% in rosin derived monomer blend,RAFT polymerization of dehydroabietic acid derived monomer was well controlled and achieved a well-defined dehydroabietic acid based polymer with polydispersity index(PDI)of 1.28.And PDI of rosin derived monomer blend based polymer was relative high in contrast to that of dehydroabietic acid based polymer,which was 1.85.However,its copolymer structure was still regarded well-defined.The rosin based polymer obtained by RAFT polymerization is also a novel Marco-RAFT agent,which can be used as a RAFT agent for next step RAFT polymerization with purpose of polymer chain extension.Additionally,the synthesized rosin based polymers all demonstrated good thermal stability.Mass loss 10% of temperature and maximum decomposing temperature was 250 oCand 350oC respectively.2.(2-methacryloyloxyisopropanol)ester of Dehydroabietic acid(DAGMA)was synthesized by esterification of dehydroabietic acid and glycidyl methacrylate.The optimum process of esterification was investigated.The optimum condition for of DAGMA is described as: triethylamine was used as catalyst,the dosage was 2% of dehydroabietic acid,the reaction time was 5h,and the reaction temperature was 120 oC.FT-IR and NMR spectra confirmed the successfully preparation of DAGMA.And the polymerization performance of DAGMA was studied by DSC and GPC.It showed that DAGMAcould be polymerized in the presence of initiator and the weight average molecular weight(Mn)of the as-prepared homopolymer was 24000~35000 g/mol.And its glass transition temperature is around 62.61 oC.The homopolymer of DAGMAalso could be prepared by RAFT.Kinetic studies showed that the copolymerization of this novel renewable monomer DAGMA was controlled.Subsequently,block polymers P(LMA-b-DAGMA)were prepared by reversible addition-fragmentation chain transfer polymerization.The results showed that using PLMA as macro-CTA resulted in a well-defined block polymer with low polydispersity,while using PDAGMA as macro-CTA resulted in a bimodal GPC curve.DSC analysis showed that the block copolymer existed phase separation,having the endothermic peak of-35 oC and the corresponding glass transition(Tg)of PLMA.The glass transition temperature of the copolymer was tailored by adjusting the amount of LMA.TGA analysis found that thermal stability significantly improved as the introduction of rosin moiety.The UV absorption of rosin based composites is indicatives of their potential application in UV-absorbent coating materials.The results of contact angle test showed that the introduction of rosin moiety endowed the block copolymer composite with improved hydrophobicity.Finally,we prepared a biodegradable dehydroabietic acid graft copolymer(PDAGMA-g-PCL)from the backbone of PDAGMA homopolymer via ring-opening of caprolactone.The successful preparation of PDAGMA-g-PCL was confirmed by NMR.The crystallization behavior of the graft copolymer was analyzed by DSC.XRD further demonstrated the synthesis of the graft copolymer.Specifically,the graft copolymer also exhibited excellent UV absorption and degradation properties.3.The nano-emulsion copolymer of PDAGMA and polystyrene(PDAGMA-b-PS)was prepared by using RAFT miniemulsion polymerization with using PDAGMA-CTA as RAFT reagent.The kinetic behavior and stability were studied.The results showed that the polymerization rate was lower under the action of initiator AIBN,but the polymerization process was controlled.And the amount of macromolecule RAFT reagent also affected the polymerization rate as well as the molecular weight and molecular weight distribution.GPC test also showed that the molecular weight of the polymer increases with the conversion rate.The dynamic laser scattering test showed that the particle size did not change with the polymerization time and maintained at around 100 nm.The diameter of final polymer latex particle obtained by TEM was almost consistent with the size by Nano ZS.Benefit from the hydrophobicity of rosin,rosin based RAFT agent didn’t transfer from emulsion particle and led to a good storage capacity of final polymer latex. |
