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Investigations on Synthesis and Structures and Properties of Styrene-N-phenylmaleimide-Maleic Anhydride Random Copolymer

Author: HuYiMin
Tutor: FanZhongYong
School: Fudan University
Course: Materials Science
Keywords: Styrene-N- phenylmaleimide - a random copolymer of maleic anhydride ternary ABS resin Synthesis Structure Performance
CLC: O631.3
Type: Master's thesis
Year: 2009
Downloads: 177
Quote: 1
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Abstract

Based on N-phenyl maleimide compound can effectively improve the heat resistance characteristics of the ABS, and a styrene-N-phenylmaleimide - maleic anhydride ternary random copolymer product (Styrene-N- phenylmaleimide-maleic anhydride Tercopolymer St-NPMI-MAH) synthetic route complex synthesis requires the use of a multi-step process, the high cost of making products, and promote the use of limited. Through the polymer molecular structure design of the heat-resistant modifier, i.e. select the N-phenylmaleimide (NPMI) for the heat main monomer, the introduction of styrene (St) in order to improve the processing of the modifier fluidity, maleic anhydride (MAH), polar monomers to improve the compatibility of the modifying agent, the terephthalic acid di-tert-butyl peroxide homemade novel initiator Step Synthesis St-NPMI-MAH random terpolymers. St-NPMI-MAH, and by adjusting the amount of monomer, the polymerization temperature and time, to prepare a heat resistance can be regulated random terpolymer. Compared with the existing industrial technology, the synthetic method reduces the technical difficulty and simplify the process and reduce production costs, the polymerization reaction conversion rate of approximately 86 wt%, can meet the requirements of industrial production, and suitable for industrial production. Thesis of heat-modifier monomer ratio, polymerization mechanism, feeding mode system focuses on the monomer ratio, polymerization temperature on the St-NPMI-MAH copolymer. Ensuring terpolymer atactic structure, the development of the solution - precipitation step polymerization the St-NPMI-MAH COPOLYMERS synthesis technique to study the relationship of the polymerization time and the yield, simplifies the polymerization process, making St-NPMI-MAH copolymer reduce the cost of synthesis. The study shows that the peroxide in phthalate, di-tert-butyl ester using self new initiator, the NPMI an amount of 30wt%, and the polymerization temperature was 125 ° C, the reaction time was 4h for optimal synthesis scheme. Using an FTIR ^{1 H NMR ^{13 C NMR, GPC technology for synthesis of St-NPMI-MAH random copolymers of the chemical composition, structure and molecular weight of chain sequences were characterization experiments show a the St-NPMI-MAH random sequence structure and monomer composition ratio relationship. Synthesis of St-NPMI-MAH copolymer has a weight average molecular weight of 5 × 10 ^{4 about a polydispersity factor of 2.2-2.7. DSC and TGA were investigated NPMI content copolymer and the same NPMI content of the copolymer of the heat resistance, thermal stability. The study found that the content of the St-NPMI-MAH copolymer glass transition temperature and the copolymer NPMI there is a linear relationship. Theoretical aspects, Ozawa method can be reasonably explained St-NPMI-MAH copolymer system non-isothermal degradation behavior and thermal degradation kinetics, and the Crane method to obtain the thermal degradation of the copolymer series. The experimental results show that the copolymer thermal degradation activation energies in 135kJ/mol to 183kJ/mol between, thermal degradation of a number of stages 1, indicating that the copolymer has an ideal thermal stability. Based on the deployment of the St-NPMI-MAH copolymer solubility parameter St-NPMI-MAH random copolymers and ABS blends, prepared ABS heat-resistant modified material. Since both having a good compatibility, blend samples DSC test showed a single glass transition step, and St-NPMI-MAH random copolymers significantly improve the heat resistance of the ABS material. Characterized using SEM microstructure and compatibility of St-NPMI-MAH random copolymer with ABS. The study found that the mechanical and rheological properties of the blends, ABS material, St-NPMl-MAH random copolymers heat modifier on the mechanical properties of materials and processing performance can remain unchanged or slightly increased. Experimental results show that this paper the development of St-NPMI-MAH random copolymer can be used as an excellent heat compatibilizer in the field of specialty polymers alloy widely used.}}}

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