Study On Preparation And Properties Of Self-crosslinking Bio-based Itaconate And Fumarate Pressure-sensitive Adhesives

Pressure-sensitive adhesives(PSAs)are widely used adhesives for the products such as tapes,tags,protective films,and can bond clean surfaces with minute pressure.However,the synthesis raw materials of PSA are highly dependent on petroleum based chemicals.Under the promotion of sustainable development policy,it is of great significance to use renewable chemicals derived from biomass to prepare bio-based PSA.In this study,the self-crosslinking bio-based itaconate PSA with high peel strength and self-crosslinking bio-based fumarate PSA with high tack were prepared by copolymerization of bio-based dibutyl itaconate(DBI)monomer and bio-based dibutyl fumarate(DBF)monomer with petroleum based acrylate monomer by using a simple process and solvent-free aqueous emulsion polymerization method,and achieved a partial replacement of petroleum based monomer.It provides a new idea for developing a new bio-based PSA.The main content of the paper is as follows:(1)Poly(dibutyl itaconate-butyl acrylate-acrylic acid)(PDBBA) PSA was prepared by emulsion polymerization process using 30 wt%～50 wt%DBI.The effects of emulsifier ratio and dosage,polymerization reaction temperature,and acrylic acid dosage on the emulsion properties and PSA properties of PDBBA were sequentially determined and the optimal synthesis conditions were determined.The effects of DBI dosage on the structure and properties of PSA were systematically investigated by ~1H NMR,GPC,DSC,and RPA characterization methods and adhesive properties testing,and the results showed that DBI could increase the high frequency shear loss modulus of PDBBA and then improve the 180°peel strength.when DBI=30 wt%,the adhesive properties of PDBBA PSA:the tack was 11#steel ball,the shear strength was 3.1 h,and the 180°peel strength was 12.6 N/25 mm.(2)To improve the shear strength of PSA,self-crosslinking monomer glycidyl methacrylate(GMA)was introduced,and self-crosslinking PDBBAG PSA was prepared by functional group reaction between the epoxy group of GMA and the carboxyl group of acrylic acid.The degree of crosslinking of PSA was controlled by changing the dosage of GMA,and the effects on the structure and properties were investigated.The introduction of chemical cross-linking system significantly improved the shear strength of PSA.When DBI=30 wt%,GMA=0.5 wt%,the adhesive properties of the self-crosslinking PDBBAG PSA:the tack was 10#steel ball,the shear strength was 46 h,the 180°peel strength was 11.8 N/25 mm,and when DBI=50 wt%,the tack was 5#steel ball,the shear strength was 31 h,the 180°peel strength was 20.2 N/25 mm.Using molecular chain transfer agents(NDM)effectively controlled the adhesive properties of PDBBAG PSA.(3)To prepare bio-based PSA with high tack,a series of self-crosslinking poly(dibutyl fumarate-butyl acrylate-acrylic acid-glycidyl methacrylate)(PBFBAG)PSA were prepared by using different dosage of DBF and acrylate monomers,and the DBF dosage increased from 10 wt%to50 wt%,the monomer conversion decreased from 98.3 to 89.7%,the tack rose and the shear strength dropped.When DBF=30 wt%and GMA=0.5 wt%,the monomer conversion of self-crosslinking bio-based PBFBAG PSA was 95.7%,the tack was 13#steel ball,the shear strength was 14 h,and the 180°peel strength was 10.3 N/25 mm.