Preparation And Properties Of Acrylate Polymer Containing Multiple Hydrogen Bonds

Multiple hydrogen bonds which has thermal reversibility and high bonding strength is able to provide a stable cross-linking point for the crosslinking structure,which provides great potential for developing or enhancing properties of the polymer material.Since the concept of"supramolecular polymer" has been proposed for the first time,the supramolecular polymer containing multiple hydrogen bonds has raised great interest.Of all the multiple hydrogen-bond systems,Upy-Upy system and Napy-UPy system have high association constant so it is greatly favored by people.We design the structure of Napy and UPy functional monomers with double bonds and alkyl group.The copolymerization of functional monomers with BA,MMA,AA were carried out through emulsion polymerization to obtain the emulsion containing multiple hydrogen bonds.The addition of functional monomers allows acrylate polymer a physical crosslinked network,which improved the properties of the emulsion film.This paper is about:(1)The effects of UPy-UPy multiple hydrogen bonds on the segments' movement,mechanical properties,viscosity,shape memory properties and adhesive properties of acrylic polymer were investigated.It showed that the glass transition temperature of the polymer is improved by increasing the UPy functional monomer.Because the the segments'movement was limited by the crosslinking network established through multiple hydrogen bonds.At the same time,when the content of UPy functional monomer increased from 0 wt%to 5 wt%,the tensile strength of the polymer increased from 13.12 MPa to 28.40 MPa and the tensile modulus also increased.The dynamic thermomechanical properties of the polymer were characterized by DMA.With the increase of the UPy functional monomer,the loss factor of the latex film decreased when the test was carried out at the frequency of 1 Hz.The effects of different frequencies on the loss factor were discussed.The activation energy of the polymer chain was calculated.The addition of UPy functional monomer increased the fixation rate and shape recovery rate of the polymer.When the content of functional monomer was 5 wt%,the shape fixation rate and shape recovery rate all exceed 90%.When the functional monomer content is constant,the increasing temperature can significantly improved the peel strength of latex film.(2)The preparation,characterization and self-repairing properties of polymer containing Napy-UPy multi-hydrogen bonds were studied.Firstly,Napy functional monomer was designed and synthesized,to give the functional monomer a long chain alkyl group,polymerizable double bonds and multiplehy drogen-bond building element.We add Napy emulsion into UPy emulsion to get the emulsion which consists of both functional monomers.The crosslinking network formed by Napy-UPy hydrogen bonds in latex films was confirmed by testing the glass transition temperature and tensile properties of latex films.In this paper,the effects of temperature,time and the ratio of Napy and UPy functional groups on the self-repairing properties of latex films were studied.The results showed that the repaing efficiency of latex film was the highest at 110? and heating for 60 min.At the same time,when the content ratio of Napy group and UPy group was 4:6,the self-repairing efficiency of latex film was the best.The repairing rate of tensile strength was 75%,and the repair rate of tensile elongation was 73%.