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Carboxyl content adjustable polyaryletherketone synthesis and Toughened Epoxy Resin

Author: ZhangBin
Tutor: WangZhongGang
School: Dalian University of Technology
Course: Polymer materials
Keywords: Epoxy Toughened Polyaryletherketone Copolymer Fracture toughness
CLC: TQ323.5
Type: Master's thesis
Year: 2011
Downloads: 110
Quote: 0
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Abstract

Epoxy is a thermosetting resin is very important, because of its good thermal stability, low shrinkage, high mechanical strength, high bond strength and good processability, etc., are widely used in aerospace, construction machinery, insulation materials and advanced composite matrix resin and other fields. But because of its crosslinking density after curing system is too high, resulting cured presence crisp, impact and fracture toughness is poor, limiting its application in some aspects. This synthesized a series of carboxyl content phenolphthalein adjustable base polyaryletherketone, and use it to toughening epoxy resin, a detailed analysis of the adjacent crosslinked polymer chain length between points on the cured epoxy resin mechanical properties, thermal properties and cross-section morphology. The main contents and conclusions are as follows: (1) using phenolphthalein (PPH), phenolphthalin (PPL) and 4,4 '- difluoro benzophenone (DFDPK) as raw materials by solution polycondensation method, synthesis of a series of different carboxyl group content of the copolymer poly aryl ether ketone PEK-L, using infrared spectroscopy (FTIR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) by means of its structure and properties were characterized, and its solubility and tensile properties were tested. The results showed that the copolymer molecular weight distribution is narrow, Mn in the range of 65000 - 83000; glass transition temperature above 220 ℃; thermal decomposition temperature is higher, the introduction of carboxyl slightly lower the thermal decomposition temperature, up to 5% weight loss temperature of 474 ℃; carboxyl groups of the polymer solvent introduced enhanced; tensile strength and tensile modulus with increasing content of carboxyl groups increased first and then leveling. (2) According to 110 ℃ 2h 140 ℃ 2h 170 ℃ 3h 200 ℃ 2h a process for curing the epoxy resin system, by DMA, DSC has been proved that the polymer is chemically completely embedded in the resin network; study of polymerization was the carboxyl group content of the cured thermal and dynamic mechanical properties, the results show, poly aryl ether ketone added to improve the cured glass transition temperature and thermal decomposition temperature of the cured Tg, and 5% weight loss temperature with The increase in carboxyl content has increased; carboxyl side groups joined polyaryl ether ketone resin system significantly reduces the loss factor, with the carboxyl group content increases, the loss factor of the cured product increases; curing system in the glass state and the rubbery state of the storage modulus increased, with the carboxyl group content increases, the glassy state storage modulus decreased slightly, while the rubber state storage modulus increased; obtained by the empirical formula, As the crosslinking density of the cured polymer is increased with the increase of carboxyl group content. (3) of adjacent carboxyl groups of the segment length and the mechanical properties of the cured cross-section morphology. Modified epoxy resin no significant improvement in flexural strength, flexural modulus decreased slightly, fracture strain improvement; polyaryletherketone join conducive epoxy K1C and G1C improvement chain segments between adjacent carboxyl longer Fracture toughness of; notched impact strength and fracture toughness showed similar trends.; SEM structure shows that the cured product is a homogeneous system, modified epoxy resin with a clear fracture toughness characteristics, carboxyl groups adjacent segment lengths less a cured little direction to brittle fracture.

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CLC: > Industrial Technology > Chemical Industry > Synthetic resins and plastics industry > Polycondensation resin and plastic > Epoxy resins and plastics
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