Copolymers from methyl methacrylate and butyl acrylate with hyperbranched architecture

Abstract

This is a first report of the synthesis and characterization of acrylic copolymers from methyl methacrylate (MMA) and butyl acrylate (BA) with hyperbranched architecture. The copolymers were synthesized using a free radical polymerization (Strathclyde method) in emulsion technique. Divinyl benzene was used as the brancher which acted as a comonomer and 1-dodecanethiol was used as a chain terminating agent. A linear copolymer from MMA and BA was also synthesized for comparison. The hyperbranched architecture was established from spectroscopic and rheological measurements. The gel permeation chromatography showed all hyperbranched copolymers were low molecular weight with lower polydispersity index (PDI) ( M n 23,000, PDI 2.00) compared to the linear grade ( M n 93,000, PDI 2.20). They were more spherical and achieved lower viscosity (yet higher solubility, >90%) than the linear grade (<50%) which was mostly open ended. Lower viscosity at equivalent solid content made the hyperbranched polymers a potential binder for adhesive and coating application.

Synthesis of Branched Poly(butyl acrylate) Using the Strathclyde Method in Continuous-Flow Microreactors

“…The mobility of the polymer chain would be weakly affected as the reaction systems were in low viscosity (below 20 cP), and the monomer conversion was almost kept the same with the variation of DDT amount for varied residence times (Figure S1a). Such results were expected as DDT solely acted as a chain transfer agent and its amount should have no obvious effect on the concentration of radical chains . When both the DDT and DVB dosages were increased simultaneously at the molar ratio of 1:1, the monomer conversion gradually decreased because of the participation of more DVB molecules in the copolymerization (Figure S1c).…”

“…The DDT residues are visible at 2.48 ppm and the broad aromatic H signal because of the DVB residues is manifested at 7.00 ppm. Figure 2b shows the FT-IR difference between l-PBA and b-PBA, and the signal at 1625 cm −1 relating to the stretching vibration absorption peak 41 of benzene ring skeleton proves the incorporation of the DVB unit into b-PBA.…”

“…Such results were expected as DDT solely acted as a chain transfer agent and its amount should have no obvious effect on the concentration of radical chains. 41 When both the DDT and DVB dosages were increased simultaneously at the molar ratio of 1:1, the monomer conversion gradually decreased because of the participation of more DVB molecules in the copolymerization (Figure S1c). Moreover, the overall chain propagation rate became slower, and the polymer solution viscosity was kept below 10 cP even at the monomer conversion of 85% (Figure S1d).…”

Branched/Hyperbranched Copolyesters from Poly(vinyl alcohol) and Citric Acid as Delivery Agents and Tissue Regeneration Scaffolds

“…[11] With higher amount of branching it was further possible to develop a compact molecular orientation with lower viscosity and stronger adhesive power. [12] Such an exclusive combination of properties started to render more benefits than what the linear polymers offer, and hence was gradually set to explore in diverse biomedical applications.…”

Enhancement of polystyrene composites by hyper-branched polymer-grafted nano-SiO2

“…Hyper-branched polymers (HBP) have attracted increasing attention since it was first fabricated by Kim and Webster in 1988 [1, 2]. HBP exhibits the typical polymeric features, such as a broad molar mass distribution and an irregular growth with a statistical distribution of the functional groups throughout the structure [3]. The tuneable end group functionality of HBP generates a wide range of property variation, which can enhance the compatibility between HBPs and other polymeric matrixes [4].…”