| The rosin, a major renewable resource, is natural resin distilled from the high viscous liquids exuded from the pine tree which is extensively widespread in the world. Rosin is also one of key natural products in China, with an annual output of about 800 000 tons. Due to the limited resource and increasing price of cruel oil, the study on the replacement of petroleum-based polymer has attracted great attention in recent years. Because of its features such as the structure and chemical reactivity, rosin has become an important resource for polymer preparation just like cellulose, lignin, starch, chitin, chitosan and natural rubber.A variety of rosin-based polymerizable monomers were synthesized by the esterification of carboxyl group in rosin or its derivatives, and characterized by IR, GC-MS, LC, NMR and DSC. The results showed that these monomers could polymerize in present of initiators. The basic properties of rosin-based monomers were described as follows:(1) Disproportionated rosin (β-acryloxyl ethyl) ester(DR-2-HEA) is mainly composed by (β-acryloxyl ethyl) esters of dehydroabietic acids (53.2%, wt) and the glass transition temperature(Tg) of its homopolymer was -20℃。(2) (2-acryloyloxy)ethyl ester of dehydroabietic acid(DHR-2-HEA)(>98%, wt) is a type of white crystals with melt point 59~61℃. It could polymerize in the present of initiator and the homopolymer has a Tg of 54.18℃.(3) (2-methylacryloyloxy)ethyl ester of dehydroabietic acid(99.8 %, wt) , a type of white crystals with melt point 54.23℃, could polymerize in the present of initiator and the Tg of its homopolymer is 73.97℃.(4) (2-methylacryloyloxy)propyl ester of dehydroabietic acid(97.7 %, wt) is a isomer and the fraction of two structures is 67.29 % and 30.25 % respectively.(5) Maleopimaric acid (99.5 %, wt), a white crystals with the melt point 232.27℃was used to synthesize the (2-acryloyloxy)ethyl ester of maleopimaric acid by acyl chlorination and esterification. (2-acryloyloxy)ethyl ester of maleopimaric acid is a kind of white crystal with melting point 99.11℃, which can polymerize without of initiator after being heated to the temperature above the melting point. The glass transition temperature of its homopolymer is 60.96℃ (6) The contents of allyl ester of dehydroabietic acid and maleopimaric acid synthesized are 98.2 % and 99.11% by weight respectively(7) Methylallyl ester of dehydroabietic acid (91.36%, wt), has a melting range of 41.24~52.24℃and the Tg of its homopolymer is -29.7℃.(8) Hydroabietyl acrylate is mainly composed of perhydrogenated abietyl acrylate, dihydroabietyl acrylate ,dehydrogenated abietyl acrylate, and small amount of methyl hydroabietate. The fraction of hydroabietyl acrylate is 80.45 wt%. Hydroabietyl acrylate can polymerize in the present of initiators. The glass transition temperature of the homopolymer is -28.92℃.The kinetics of homopolymerization of the above rosin-based monomers was evaluated by non-isothermal or isothermal DSC measurement. The results showed that the activation energy of homopolymerization of rosin-based monomers in descending order was as follows: Methylallyl ester of dehydroabietic acid > Disproportionated rosin (β-acryloxyl ethyl) ester > hydroabietyl acrylate > Disproportionated rosin (β-methylacryloxyl ethyl) ester > (2-methylacryloyloxy)ethyl ester of dehydroabietic acid > (2-methylacryloyloxy)propyl ester of dehydroabietic acid. All the homopolymers are kind of oligomers with molecular weight ranging from 4000 to 30000, which shows that those rosin-based monomers is more sutiable for copolymerization.Acrylate hybrid emulsions containing (2-acryloyloxy)ethyl ester of dehydroabietic acid (DHR-2-HEA), dehydroabietic acid (DHR) or disproportionated rosin (DR) were synthesized by miniemulsion polymerization respectively and characterized by the DSL and TEM. It was found that the particle sizes of hybrid emulsions by using different rosin based monomers were almost same when same emulsifiers and initiator were used. The introduction of DHR-2-HEA had no significant impact on molecular weight of the copolymer. However, the molecular weight of the copolymers decreased with the increase of the amount of DR or DHR. The result of DSC measurement showed that both of DHR and DR are compatible with poly(methyl methacrylate) (PMMA). The Tg of copolymers decreased with the increase of the amount of the rosin based monomers, especially in the case of DR and DHR. It is obvious that the introduction of DHR-2-HEA could increase the storage modulus and tensile strength of copolymer. On the contrary, the storage modulus and tensile strength of copolymer decreased with the increase of content of DR or DHR. By the contact angle evaluation, the copolymer containing DR or DHR was more hydrophobic than that of DHR-2-HEA.The pressure sensitive adhesives (PSA) based on acrylate hybrid emulsions containing rosin-based monomers were also formulated and their performance was evaluated. The results showed that the initial adhesion and 180°peeling strength of PSA were improved and the persistent adhesion decreased when DR or DHR was added. However, the introduction of disproportionated rosin (β-methylacryloxyl ethyl) ester (DR-2-HEMA) did not affect the initial adhesion and 180°peeling strength of PSA, although the persistent adhesion decrease slightly, which reflected that DR-2-HEMA was more suitable for the preparation of heat active resin. With two acrylate groups, acrylic rosin (β-methylacryloxyl ethyl) ester (AR-2-HEMA) could be used as crosslinking monomer to increase the persistent adhesion of PSA. However it also led to the decrease of initial adhesion and 180°peeling strength. DR was proved to improve the hydrophobicity of the copolymers and reduce the surface tension of PSA film by the contact angle measurements, while DR-2-HEMA had no significant effect on the surface tension.The ultraviolet curing coatings based on the rosin-based monomer were prepared and evaluated. It was found that DR-2-HEA and acrylic rosin (β-acryloxyl ethyl) ester (AR-2-HEA) could increase the pencile hardness of coating film. However, the coating based on DR-2-HEA and AR-2-HEA showed poorer adhesion to glass, particularly when the content of AR-2-HEA was increased. The introduction of a small amount of 2-hydroxyethyl acrylate could improve significantly the adhesion of coating, without reducing the pencile hardness. The suitable mass fraction of coating for glass was DR-2-HEA (50 %), AR-2-HEA (30 %) and additives (20 %).
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