The influence of laminate thickness of polymer matrix composites on moisture diffusion in seawater immersion, as well as the resulting mechanical property degradation for composites of glass/isopolyester （G/IPE）, ca...The influence of laminate thickness of polymer matrix composites on moisture diffusion in seawater immersion, as well as the resulting mechanical property degradation for composites of glass/isopolyester （G/IPE）, carbon/isopolyester （C/IPE）, glass/vinylester （G/VE） and carbon/vinylester （CNE）, was investigated in this paper. Laminates 3 and 10 mm in thickness, fabricated using the wet hand lay-up technique, were characterized for moisture absorption in artificial seawater medium, and their flexural strength and interlaminar shear strength （ILSS） degradations were studied. Moisture diffusion was observed to be anamolous to the Fick＇s law for both 3 and 10 mm thick samples in the later stage of diffusion. Moisture permeability of 10 mm thick samples was two to three order greater than that of 3 mm thick ones, while the time to moisture saturation remained unchanged. With the increase of laminate thickness, moisture saturation increased by 1.4% for CNE and 7% for GriPE. The residual flexural strength and ILSS were greater in case of 10 mm thick specimens after 200 days of exposure. SEM examination of the fractured specimens showed greater levels of fibre/matrix debonding in 10 mm thick specimens.展开更多
The Sodium Montmorillonite(Na-MMT)is not susceptible to polymer due to its organophilic character and low basal spacing.The primary objective of this study was to improve Na-MMT platelets separation by organically mod...The Sodium Montmorillonite(Na-MMT)is not susceptible to polymer due to its organophilic character and low basal spacing.The primary objective of this study was to improve Na-MMT platelets separation by organically modifying it with cation and anion exchanges using Cetyl trimethyl ammonium bromide(CTAB)and Sodium dodecyl sulfate(SDS)respectively.Basal spacing,presence of functional groups,Zetapotential with particle size analysis and thermal stability of the Organomodified Na-MMT(OMMT)were characterized using XRD,FTIR,zeta-potential analyzer and TGA respectively.The basal spacing of CTAB modified OMMTincreased to 19.5Åfrom 11.0Åwhich corresponds to the basal spacing of Na-MMT.The SDS modified OMMT did not show any increase in the basal spacing.FTIR spectra of CTAB modified Na-MMT illustrated the attachment of CTAB functional groups to Na-MMT,while the same was absent in the case of SDS modified Na-MMT.The zeta-potential of Na-MMT shifted from–24.88 mV to 15.66 mV in the case of CTAB modified Na-MMTand 12.49 mV for SDS modified Na-MMT,indicating a greater surface potential of the modified nanoclay.The TGA showed greater weight loss for CTAB modified Na-MMT than that for Na-MMT,indicating the effective Na+ion exchange with alkyl amines.展开更多
文摘The influence of laminate thickness of polymer matrix composites on moisture diffusion in seawater immersion, as well as the resulting mechanical property degradation for composites of glass/isopolyester （G/IPE）, carbon/isopolyester （C/IPE）, glass/vinylester （G/VE） and carbon/vinylester （CNE）, was investigated in this paper. Laminates 3 and 10 mm in thickness, fabricated using the wet hand lay-up technique, were characterized for moisture absorption in artificial seawater medium, and their flexural strength and interlaminar shear strength （ILSS） degradations were studied. Moisture diffusion was observed to be anamolous to the Fick＇s law for both 3 and 10 mm thick samples in the later stage of diffusion. Moisture permeability of 10 mm thick samples was two to three order greater than that of 3 mm thick ones, while the time to moisture saturation remained unchanged. With the increase of laminate thickness, moisture saturation increased by 1.4% for CNE and 7% for GriPE. The residual flexural strength and ILSS were greater in case of 10 mm thick specimens after 200 days of exposure. SEM examination of the fractured specimens showed greater levels of fibre/matrix debonding in 10 mm thick specimens.
文摘The Sodium Montmorillonite(Na-MMT)is not susceptible to polymer due to its organophilic character and low basal spacing.The primary objective of this study was to improve Na-MMT platelets separation by organically modifying it with cation and anion exchanges using Cetyl trimethyl ammonium bromide(CTAB)and Sodium dodecyl sulfate(SDS)respectively.Basal spacing,presence of functional groups,Zetapotential with particle size analysis and thermal stability of the Organomodified Na-MMT(OMMT)were characterized using XRD,FTIR,zeta-potential analyzer and TGA respectively.The basal spacing of CTAB modified OMMTincreased to 19.5Åfrom 11.0Åwhich corresponds to the basal spacing of Na-MMT.The SDS modified OMMT did not show any increase in the basal spacing.FTIR spectra of CTAB modified Na-MMT illustrated the attachment of CTAB functional groups to Na-MMT,while the same was absent in the case of SDS modified Na-MMT.The zeta-potential of Na-MMT shifted from–24.88 mV to 15.66 mV in the case of CTAB modified Na-MMTand 12.49 mV for SDS modified Na-MMT,indicating a greater surface potential of the modified nanoclay.The TGA showed greater weight loss for CTAB modified Na-MMT than that for Na-MMT,indicating the effective Na+ion exchange with alkyl amines.
