scholarly journals A study on the mechanical, thermal properties and crystallization behavior of poly(lactic acid)/thermoplastic poly(propylene carbonate) polyurethane blends

RSC Advances ◽  
2017 ◽  
Vol 7 (73) ◽  
pp. 46183-46194 ◽  
Author(s):  
Jia Yang ◽  
Hongwei Pan ◽  
Xin Li ◽  
Shulin Sun ◽  
Huiliang Zhang ◽  
...  

PPCU was prepared by using PPC and polyols as the raw materials and diphenyl-methane-diisocyanate (MDI) as the extender chain. The impact strength and elongation at break of PLA were remarkably enhanced by blending with PPCU.

2019 ◽  
Vol 798 ◽  
pp. 279-284
Author(s):  
Pajaera Patanathabutr ◽  
Patiphan Soysang ◽  
Pakjira Leuang-On ◽  
Piyapon Kasetsupsin ◽  
Nattakarn Hongsriphan

This study was designed to evaluate properties of poly(lactic acid) (PLA) under the postulation that recycled PLA (rPLA) was contaminated with commodity thermoplastics during a typical density-based sorting. Change in clarity, mechanical, and thermal properties of the contaminated rPLA specimens were compared. Clarity of rPLA was reduced showing pale brownish tint when passing multiple processing. Contamination with either PP or HIPS just 1 phr caused rPLA to become opaque, which the transmittance percentage was decreased with respect to contamination content. Compared to pure PLA, the moduli of rPLA was reduced 2.6%. The moduli of rPLA was reduced 4.5-8.2% when contaminated with PP of 1-8 phr, and the moduli was reduced 1.4-4.1% when contaminated with HIPS of 1-8 phr. Elongation at break of PP-contaminated rPLA specimens was reduced with slight increase of impact strength. Elongation at break of HIPS-contaminated rPLA specimens was higher with higher HIPS content, and the impact strength was enhanced up to 64%.


2019 ◽  
Vol 972 ◽  
pp. 178-184
Author(s):  
Sirirat Wacharawichanant ◽  
Chawisa Wisuttrakarn ◽  
Kasana Chomphunoi ◽  
Manop Phankokkruad

This research prepared poly(lactic acid) (PLA) and PLA/acrylonitrile-butadiene rubber (NBR) blends before and after adding polyethylene-g-maleic anhydride with 3 wt% of maleic anhydride (PE-g-MA3) 3 phr. The effects of NBR and PE-g-MA3 on morphological, mechanical and thermal properties of PLA and PLA blends were discussed. The morphological analysis observed the two-phase morphology of PLA/NBR blends, and it was observed the cavities generated due to NBR phase detachment during sample fracture, and droplets of NBR phase at higher NBR content. The PE-g-MA3 addition could improve adhesion between PLA and NBR phases due to the decrease of cavities in PLA matrix and droplet size of NBR. The mechanical properties showed the impact strength and strain at break of PLA/NBR blends dramatically increased when the amount of NBR increasing. The addition of PE-g-MA3 significantly improved the impact strength of PLA/NBR blends. The thermal properties showed the NBR addition had effect slightly on the melting temperature of PLA/NBR blends. The filling of NBR and PE-g-MA3 greatly decreased the percent crystallinity of PLA more than two times. The thermal degradation of pure PLA and NBR proceeds by one step, while the thermal degradation process of PLA/NBR and PLA/PE-g-MA3 proceeds by two steps. Which the first step showed a large mass loss of PLA degradation and the second step showed a small mass loss of PE-g-MA and NBR degradation.


2018 ◽  
Vol 75 (12) ◽  
pp. 5437-5454 ◽  
Author(s):  
Ye Zhou ◽  
Jiao Wang ◽  
Shen-Yang Cai ◽  
Zhi-Gang Wang ◽  
Nai-Wen Zhang ◽  
...  

2011 ◽  
Vol 410 ◽  
pp. 59-62 ◽  
Author(s):  
Punmanee Juntuek ◽  
Chaiwat Ruksakulpiwat ◽  
Pranee Chumsamrong ◽  
Yupaporn Ruksakulpiwat

From our previous study, natural rubber (NR) was used to improve toughness of poly (lactic acid) (PLA). Impact strength and elongation at break of PLA was increased when adding NR. Moreover, by using NR-g-GMA as compatibilizer for PLA and NR blend, impact strength and elongation at break was improved. However, tensile strength and modulus of PLA/NR blend with and without NR-g-GMA were decreased. In this study, calcium carbonate (CaCO3) and vetiver grass fiber were used as fillers in PLA/NR blend. With the addition of CaCO3 into PLA/NR blend with NR-g-GMA, impact strength and modulus of the composite were further increased with a loss in tensile strength. In contrast, the addition of vetiver grass fiber into PLA/NR blend with NR-g-GMA led to an increase in tensile strength and modulus and a decrease in impact strength and elongation at break. The onset degradation temperatures of PLA composites were lower than that of PLA and PLA/NR blend.


2013 ◽  
Vol 1499 ◽  
Author(s):  
Eda Acik ◽  
Ulku Yilmazer

ABSTRACTTernary nanocomposites of poly (lactic acid) (PLA) were produced by melt blending with two types of elastomers and five types of organoclays to obtain improved mechanical properties such as tensile strength, modulus and impact strength. One of the elastomers is a random copolymer of ethylene and glycidyl methacrylate (E-GMA) and the other one is a random terpolymer of ethylene-butyl acrylate-maleic anhydride (E-BA-MAH). Organically modified montmorillonites (OMMT) were utilized as nanofillers. XRD, DSC, tensile and impact tests were done on the injection molded samples. FTIR, SEM and TEM analyses are still in progress. As preliminary results, thermal analysis showed that the addition of compatibilizers and organoclays does not have a distinct effect on the thermal properties of the composites, and no evidence of nucleation activity of compatibilizers or organoclays was found. For all types of organoclays, the nanocomposites produced with E-GMA exhibited better mechanical properties in comparison to nanocomposites containing E-BA-MAH, especially for the impact strength.


2011 ◽  
Vol 31 (6-7) ◽  
Author(s):  
Fang-Cheng Pai ◽  
Hou-Hsein Chu ◽  
Sun-Mou Lai

Abstract A melt blending process was used to prepare poly(lactic acid) (PLA)/metallocene catalyzed polyethylene octene copolymer (POE) blends in order to toughen PLA. A commercialized ethylene-glycidyl methacrylate copolymer (EGMA) was applied as a compatibilizer to improve the dispersion and interaction of dispersed POE to the PLA matrix. The results showed that chemical interaction seems to be the driving force for reinforcing the compatibility between PLA and POE, and also the dispersion of POE into the PLA matrix domain. With the incorporation of 10 phr EGMA in the blends, POE was well-dispersed at a sub-micrometer scale within the PLA matrix, indicating better interfacial compatibility between PLA and POE. The impact strength test revealed that POE could significantly toughen PLA containing EGMA in the blends, up to no-break level regarding unnotched Izod impact strength at 10 phr EGMA content. With the increase of EGMA content, the blends showed lower tensile strength, but higher elongation at break due to the elastomeric characteristics of EGMA. When 10 phr of the EGMA was incorporated into the blends, its elongation at break reached 54.5%, 10.7 times that of neat PLA at 5.1%. The melt viscosity of compatibilized blends containing 10 phr EGMA increased by more than 50% in comparison with the non-compatibilized blend, which implied a good interfacial interaction between the PLA and POE interface.


2014 ◽  
Vol 970 ◽  
pp. 312-316
Author(s):  
Sujaree Tachaphiboonsap ◽  
Kasama Jarukumjorn

Thermoplastic starch (TPS)/poly (lactic acid) (PLA) blend and thermoplastic starch (TPS)/poly (lactic acid) (PLA)/poly (butylene adipate-co-terephthalate) (PBAT) blend were prepared by melt blending method. PLA grafted with maleic anhydride (PLA-g-MA) was used as a compatibilizer to improve the compatibility of the blends. As TPS was incorporated into PLA, elongation at break was increased while tensile strength, tensile modulus, and impact strength were decreased. Tensile properties and impact properties of TPS/PLA blend were improved with adding PLA-g-MA indicating the enhancement of interfacial adhesion between PLA and TPS. With increasing PBAT content, elongation at break and impact strength of TPS/PLA blends were improved. The addition of TPS decreased glass transition temperature (Tg), crystallization temperature (Tc), and melting temperature (Tm) of PLA. Tgand Tcof TPS/PLA blend were decreased by incorporating PLA-g-MA. However, the presence of PBAT reduced Tcof TPS/PLA blend. Thermal properties of TPS/PLA/PBAT blends did not change with increasing PBAT content. SEM micrographs revealed that the compatibilized TPS/PLA blends exhibited finer morphology when compared to the uncompatibilized TPS/PLA blend.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Wei Kit Chee ◽  
Nor Azowa Ibrahim ◽  
Norhazlin Zainuddin ◽  
Mohd Faizal Abd Rahman ◽  
Buong Woei Chieng

Poly(lactic acid) (PLA)/poly(ε-caprolactone) (PCL) blends were prepared via melt blending technique. Glycidyl methacrylate (GMA) was added as reactive compatibilizer to improve the interfacial adhesion between immiscible phases of PLA and PCL matrices. Tensile test revealed that optimum in elongation at break of approximately 327% achieved when GMA loading was up to 3wt%. Slight drop in tensile strength and tensile modulus at optimum ratio suggested that the blends were tuned to be deformable. Flexural studies showed slight drop in flexural strength and modulus when GMA wt% increases as a result of improved flexibility by finer dispersion of PCL in PLA matrix. Besides, incorporation of GMA in the blends remarkably improved the impact strength. Highest impact strength was achieved (160% compared to pure PLA/PCL blend) when GMA loading was up to 3 wt%. SEM analysis revealed improved interfacial adhesion between PLA/PCL blends in the presence of GMA. Finer dispersion and smooth surface of the specimens were noted as GMA loading increases, indicating that addition of GMA eventually improved the interfacial compatibility of the nonmiscible blend.


e-Polymers ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 39-54 ◽  
Author(s):  
Bo Wang ◽  
Yujuan Jin ◽  
Kai’er Kang ◽  
Nan Yang ◽  
Yunxuan Weng ◽  
...  

AbstractIn this study, a type of epoxy-terminated branched polymer (ETBP) was used as an interface compati- bilizer to modify the poly lactic acid (PLA)/poly(butylene adipate-co-butylene terephthalate) (PBAT) (70/30) blends. Upon addition of ETBP, the difference in glass transition temperature between PLA and PBAT became smaller. By adding 3.0 phr of ETBP, the elongation at break of the PLA/PBAT blends was found increased from 45.8% to 272.0%; the impact strength increased from 26.2 kJ·m−2 to 45.3 kJ·m−2. In SEM analysis, it was observed that the size of the dispersed PBAT particle decreased with the increasing of ETBP content. These results indicated that the compatibility between PLA and PBAT can be effectively enhanced by using ETBP as the modifier. The modification mechanism was discussed in detail. It proposes that both physical and chemical micro-crosslinking were formed, the latter of which was confirmed by gel content analysis.


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