Preparation Of Nano-cellulose Grafted Methacrylic Acid And Research Performance Of Modified PMMA

PMMA is a kind of important polymer,belonging to the amorphous thermoplastic plastics,with good electrical insulation,weatherability,mechanical properties,optical properties and chemical stability,widely used in construction,aviation,agriculture,optical instruments,Bio Medical and other field.Cellulose is the nature inexhaustible,inexhaustible and renewable natural polymer,nano-cellulose?NCC?can be obtained by acid hydrolysis or enzymatic hydrolysis handle natural cellulose.Compared with ordinary non nano-cellulose,NCC has the characteristics of high purity,high crystallinity,high strength and so on.It has applications in many fields such as medicine,paper making,composite materials and so on.Because of the large number of hydrophilic hydroxyl groups exist in the structure of NCC molecules.So the compatibility between the polymer matrix and NCC is poor,which limits its application in a certain range.The grafting modification of surface of NCC was carried out by free radical polymerization,the new group was introduced,and the excellent properties of NCC were retained,at the same time,improving the compatibility between NCC and PMMA,enhancing the thermal performance hardness,impact strength of PMMA,expanding the scope of application of PMMA.In this paper,the stable NCC suspension was obtained by the use of acid hydrolyzed medical absorbent cotton.Using potassium persulfate?k₂S₂O₈?as initiator,the surface of NCC was grafted with methyl acrylic acid?MA?monomer,and the NCC-g-MA was obtained.With benzoyl peroxide?BPO?as initiator,PMMA/NCC-g-MA composite was prepared by bulk polymerization,NCC-g-MA was added to methyl methacrylate?MMA?.The structure and properties of NCC and NCC-g-MA were tested and characterized by fourier transform infrared spectroscopy?FTIR?,scanning electron microscopy?SEM?,transmission electron microscopy?TEM?,X-ray diffraction?XRD?,thermal gravimetric analysis?TG?and differential thermal analysis?DSC?.The performance of PMMA/NCC-g-MA was analyzed by the test of thermal performance,hardness,impact strength and so on.The experimental results show that the compatibility of NCC-g-MA with PMMA is better than that of NCC.The dosage of NCC-g-MA dosage is 0.2 wt%of PMMA,the hardness of PMMA/NCC-g-MA improve the fastest,at this time,the hardness of PMMA/NCC-g-MA hardness is 19.8 Hv,the impact strength of PMMA/NCC-g-MA improve the faster,the impact strength of the PMMA/NCC-g-MA is 19.94 kJ.Compared with PMMA,the hardness and impact strength of PMMA/NCC-g-MA composites have been improved.