Investigation On CF/GF Reinforced PPESK Composite

PPESK, which offered high wear resistance, heat resistance, high strength, good electric insulation.etc, and not only included simple synthesis process, but also had low materials cost, was a new kind of high performance special engineering plastics.This paper based on the actual project of LiaoHe oil field petroleum tools, made use of the CF/GF hybrid fiber to reinforce PPESK resin, prepared short fiber hybrid reinforced PPESK composite centralizer with injection molding process, made long fiber hybrid reinforced PPESK composite pumping rod with Pultrusion process.1.Discussed on CF surface pretreatment scheme, used the composite surface treatment method which gas phase after the first liquid phase, with different temperature oxidation treatment and different time nitric acid etching process to these fibers, respectively, and used the WDW-200 universal tensile testing machine and SEM, tested CF tensile strength and observed the change of the fiber surface morphology separately that by non-treatment, the oxidation treatment and the oxidation+ nitric acid etching process; Used infrared spectrum analysis the change of functional groups of CF which after preprocessing, eventually determine the CF surface pretreatment solution was: oxidation treatment(450℃,40 min)+nitric acid etching process(20min)+dipped in deionized water(20min) +drying(120℃,3h);Infrared spectrum analysis showed that the surface perssad of CF that by oxidation treatment(450℃,40 min)+nitric acid etching process(20min) happened to transform from the hydroxyl to the carbonyl or the carboxyl with the C=O double bond.2.Studied the short CF/GF hybrid reinforced PPESK composite molding process,respectively set the different fiber mass fraction, and combined with the service conditions of the oil tools centralizer test abrasion resistance, impact resistance and thermal expansion performance. Used SEM to observe the fracture and friction surface morphology of sample, analyze the compatibility of fiber and matrix and its wear mechanism; when hybrid ratio was different, discussed the distribution principle of fibers in the matrix and hybrid enhancement effect, and established the fiber hybrid model. Results show that compared with the pure GF reinforced PPESK composite,the addition of CF obviously improve the thermal stability and mechanical properties of composite materials, Combined with the Mechanical performance analysis,ultimately determined the best technology parameters of short fiber hybrid reinforced PPESK composite as follows: the screw rotation speed was 60 RPM, extrusion temperature range was 270℃~270℃, mixed ratio was 15%CF/20%GF, and when thecomposite materials under external load, the GF mainly had the effect of enhanced interfacial bonding, and absorbed some of the impact energy; And the CF mainly strengthen the skeleton, assume the main impact load.3.Studied the long CF/GF hybrid reinforced PPESK composite molding process,respectively, set the different fiber mass fraction,then test their tensile strength, by means of SEM observed composite material fracture, and analysed its fiber hybrid effect. Results show that when composite materials under external load, the CF mainly had the effect of resistance to tensile strength, and the GF could be able to provide a certain amount of tensile strength, besides, also had good bonding effect with matrix, avoid the influence of tensile strength decreased for fiber increase causes interface number increase. With mechanical performance analysis, and ultimately determine the best parameters of long CF/GF hybrid reinforced PPESK composite materials pultrusion process as follows: pultrusion speed was 20mm/s, the heating temperature was 285℃, mold temperature was 200℃-160℃, the fiber hybrid ratio was 15%GF/35%CF.