Preparation of Hollow-Porous Rosin-Based Polyurethane Microspheres with pH-Responsive Characteristics

Abstract

Preparation of polymer microspheres from naturally occurring resource is a challenge. Here, a rosin-based polyol (RAG) was used to prepare polyurethane resin (RPU) firstly, and then act as both self-assembled precursor and emulsifier, rosin based polyurethane microspheres (RPUMs) were prepared. In the process of self-emulsification, the RPU formed vesicles by self-assembly. The outer shell of the vesicle consisted of hydrophilic segments, while the inner shell contained the hydrophobic phase. After cross-linking the RPU and removal of the solvent in the core, the porous-hollow microspheres with pH-sensitive were obtained. The microspheres were characterized by optical microscope (OM), scanning electron microscopy (SEM) and transmission electron microscope (TEM). The effect of type and amount of the hydrophilic chain extender, and solvent on the morphology, particle size and distribution, and buffer volume of the microspheres were determined. The best conditions for synthetic RPUMs were as follows: n NCO /n OH = 1, n RAG :n 1-(2-hydroxyethyl) piperazine = 4:6, with azodiisobutyronitrile level of 1.0 wt.%, based on reactive monomers, mixing speed of both emulsification and polymerization at 400 r•min -1 , the RPUMs synthesized had porous-hollow structure with a buffer volume of 1.6 mL.

Sustainable cycloaliphatic polyurethanes: from synthesis to applications

“…The morphology, particle size, particle distribution and buffer volume of the microspheres were impacted by these parameters. 428 PU networks from betulin, using triphenylmethane triisocyanate as a cross-linker have also been prepared. Three rigid aliphatic cycles of the betulin introduced frustrated packing.…”

“…The morphology, particle size, particle distribution and buffer volume of the microspheres were impacted by these parameters. 428…”

Cross-linked self-healing polymers containing rosin moiety based on dynamic urea and multiple hydrogen bonds

“…These products are introduced into polymer chains to obtain network polymers with good mechanical properties and homogeneous structures. At present, the main research on rosin in the field of polymer materials includes the fabrication of light-controllable amphiphilic polymers [19], polyurethane microspheres [20,21], antibacterial coatings [22], marine antifouling coatings [23], and supramolecular hydrogels [24]. As a renewable biomass resource, rosin and its derivatives have significant research potential and application prospects in the fabrication of polymeric self-healing materials.…”