Research On Toughening Modification Of PMMA

PMMA (organic glass)has such excellent properties as high light transmittance, colorlessness,chemical resistance, and dimensional stability.However, it has a poor impact resistance or brittle. Considerable attempts had been made to modify the macromolecular structure or phase structure in order to improve the impact resistance(toughening ) of PMMA and to satisfy special engineering requirements.In this paper these toughening methods are systemically reviewed,which include:(l)co-polymerization with appropriate monomer; (2) blending with second phase particles; (3) Inter-penetrating Polymer Networks structure(IPN); (4) bi-oriented extension process; (5) fiber reinforcement technologyA major goal of this paper is to extend the utilization of the organic glass by improving to impact resistance.After studying the PMMA performances and the factors affected, the author investigated the following experiments:(l)the toughening of PMMA by PBA;(2)A series of PBA core-PMMA shell particles were prepared using emulsion polymerization, were utilized as modifiers for PMMA;(3)MAAS elastic body was prepared by emulsion polymerization in which methyl methacrylate(MMA),butyl acrylate(BA),acrylonitrile(AN) and styrene(St)were used as monomers. MAAS was used in the study as toughening modifier of PMMA;(4)the toughening of PMMA by Polyamidc Copolymer(COPA);Study shows that:(1)toughening of PMMA by PBA and PBA/PMMA core-shell modifier ,which possess good impact strength, and the Izod notched impack strength of toughening modified PMMA by PBA/PMMA core-shell modifier is much butter than PMMA by PBA.(2)the impact strength of the modified PMMA was improved greatly through filling COPA, while the tensile strength and bending strength was decreased. (3)the acrylonitrile content of MAAS not only affects the performance of grafting reaction ,but also the mechanical properties of MAAS/PMMA blends, so the acrylonitrile content should be controlld between 5 to 15% when MAAS synthesized,and the impact strength of MAAS/PMMA was increased 39.5% when the MAAS mass fraction was 10wt% and the acrylonitrile content of MAAS was 15%.