การประยุกต์ใช้โคพอลิเมอร์และออร์กาโนเคลย์เพื่อใช้เป็นสารช่วยผสมและสารปรับปรุงสมบัติในพอลิเมอร์ผสม

บทคัดย่อ

The first parts studied the effects of polypropylene-graft-maleic anhydride (PP-g-MA) compatibilizers on the morphology and mechanical properties of polyoxymethylene (POM)/acrylonitrile-butadiene-styrene (ABS) blends. Two types of ompatibilizers, PP-g-MA with maleic anhydride 0.50 wt% (PP-g-MA3150) and PP-g-MA with maleic anhydride 1.305 wt% (PPg-MA353) were used. POM/ABS blends without and with PP-g-MA compatibilizer were prepared by an internal mixer and molded by compression molding. The results found that POM/ABS blends clearly demonstrated a two phase separation of dispersed ABS phase and the POM matrix phase, and ABS phase dispersed as spherical domains in POM matrix in a range of ABS 10-30 wt% and the blends containing ABS more than 30 wt% showed the elongated structure of ABS phase. The mechanical properties showed that the impact strength of POM/ABS with ABS content of 10-20 wt% decreased with the increase of ABS content. The Young’s modulus of POM/ABS blends increased up to 30 wt% of ABS and then decreased. The addition of PP-g-MA increased the tensile strength of POM/ABS blends in a range of 30-40 wt% of ABS. The second parts studied the effects of PP-g-MA compatibilizer on the mechanical thermal and morphological properties of POM/polypropylene (PP) blends. POM/PP blends without and with PP-g-MA compatibilizer were prepared by an internal mixer and molded by compression molding. The results found that the morphology of POM/PP blends clearly demonstrated a two phase separation of dispersed PP phase and the POM matrix phase and the addition of PP-gMA changed the morphological characteristics of blends. POM/PP blends showed the decrease of mechanical properties with increasing of PP content. The addition of PP-g-MA improved Youngs modulus and storage modulus of POM/PP blends. The incorporation of PP improved the degradation temperature of POM. The third parts studied the effects of the nanoclay with modified surface by 25-30 wt% of octadecylamine (Clay-ODA) on mechanical and morphological properties of poly(methyl methacrylate) (PMMA)/ethylene-octene copolymer (EOC8180)/Clay-ODA composites. The PMMA/EOC blends without and with Clay-ODA were prepared by melt mixing in an internal mixer. The ratio of PMMA and EOC8180 was 80/20 by weight and the Clay-ODA content was 3 and 5 phr. The results showed Young’s modulus of the composites increased with increasing Clay-ODA content. While the impact strength, tensile strength and strain at break of the composites decreased with increasing Clay-ODA content. Scanning electron microscopy analysis showed that the droplet of dispersed EOC8180 phase in PMMA matrix was changed to the elongated structure after adding Clay-ODA. The forth parts studied the effects of three types of organoclay on mechanical and morphological properties of high density polyethylene (HDPE)/ethylene copolymer (EC)/ organoclay composites. The two types of EC; ethylene-methyl acrylate copolymer (EMAC) and EOC8180 were used to prepare polymer blends. The three types of organoclay; nanoclay with modified surface by 25-30 wt% of trimethyl stearyl ammonium (Clay-TSA), nanoclay with modified surface by 35-45 wt% of dimethyl dialkyl (C14-C18) amine (Clay-DDA), nanoclay with modified surface by 25-30 wt% of methyl dihydroxyethyl hydrogenated tallow ammonium (Clay-MHA). The HDPE/EC blends without and with organoclay were prepared by melt mixing in an internal mixer. The ratio of HDPE and EC was 80/20 by weight and the organoclay content was 3 phr. The results found that the modulus and tensile stress at break of HDPE/EMAC blends increased after adding Clay-MHA, while the modulus of HDPE/EOC8180 blends did not change when added all organoclay types. The tensile strain at break of HDPE/EOC8180 blends without and with organoclay was higher than that of HDPE/EMAC blends without and with organoclay. The addition of all organoclay types had not effect significantly on the tensile strain at break of HDPE/EMAC blends. Scanning electron microscopy analysis observed that the compatibility of HDPE and EC phases in polymer blends both without and with organoclay due to HDPE can be miscible with EC and organoclay. However, the addition of Clay-MHA observed the promoting effect on polymer phase morphology that displayed the completely different morphology from the other organoclay types, and showed the more ductile of composites, so this structure induced the increment of the modulus and tensile stress at break. The fifth parts studied the effects of three organoclay types; Clay-DDA, Clay-TSA and Clay-MHA on mechanical and morphological properties of POM/PP blends. The morphology results revealed the size of dispersed PP phase decreased with increasing organoclay content. X-ray diffraction results showed clay occurred the exfoliated structure in POM/PP/organoclay (80/20/5) composites at all types of organoclay. Incorporation of organoclay improved the Young’s modulus but dropped the strain at break of the blends. The POM/PP blends containing Clay-MHA revealed the highest tensile strength due to better exfoliated structure in the POM/PP/Clay-MHA composites. The sixth parts studied the effects of Clay-MHA on morphology and mechanical properties of poly(lactic acid) (PLA4043D)/EC blends without and with organoclay. The two types of EC;EMAC, ethylene-octene copolymer (EOC8100), were used to prepare PLA4043D/EC blends. The blends of PLA4043D/EC without and with organoclay were prepared by melt mixing in an internal mixer. The ratio of PLA4043D and EC was 80/20 by weight and the organoclay contents were 1, 3 and 5 phr. Scanning electron microscopy analysis showed that the addition of organoclay could improve the miscibility of PLA4043D and EC phases due to the domain size of dispersed EC phase decreased with increasing organoclay content. This indicated that the organoclay played an important role in reducing domain size of the dispersed EC phase of the PLA4043D/EC blends. The mechanical properties showed that Young’s modulus and stress at break of the PLA4043D /EC/organoclay composites increased with increasing organclay content. While the strain at break decreased with increasing organocaly content. Additionally, the most mechanical properties of PLA4043D/EMAC/organoclay composites were better than that of PLA4043D/EOC8100/ organoclay composites.

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