Article
Thermodynamics
Jana Navratilova, Lenka Gajzlerova, Lukas Kovar, Roman Cermak
Summary: The study compared high-pressure crystallization and polymorphic composition between long-chain branched polypropylene (LCB-PP) and linear isotactic polypropylene (PP). It found that LCB-PP crystallizes at a higher temperature than PP under low pressure, but the opposite occurs under high pressure. LCB-PP tends to crystallize into orthorhombic gamma-form, while PP does not form pure gamma-form samples.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Polymer Science
Sandra Romero-Diez, Mu Sung Kweon, Eric S. Kim, Anvit Gupta, Xuejia Yan, George Pehlert, Chul B. Park, Patrick C. Lee
Summary: This study investigated the crystallization behaviors of two different high-melt-strength polypropylene resins using a novel high-pressure visualization system, and found that crystal growth rates and nucleation densities increase with higher applied shear stress but reach an optimum value with increasing CO2 pressure. By selectively choosing processing conditions, observable critical size nuclei can be enhanced and CO2 exclusion from crystal growth front can be achieved, allowing for easy control over overall crystallization kinetics through induced-shear stress and pressurized CO2.
Article
Polymer Science
Shaojie Zhang, Xiangyun Gong, Caixia Zhao, Guoxiang Zou
Summary: Long-chain branched polylactides with high melt strength were prepared by a melting reaction, and the occurrence of chain scissions, branching reactions, and cross-linking reactions were confirmed. Both the branch-on-branch and cross-linked architectures were observed with an increase in the content of Trigonox301 or DCP. The presence of gel fraction indicated a higher likelihood of cross-linking reactions in PLA-LCBD samples, compared to PLA-LCBT.
POLYMERS FOR ADVANCED TECHNOLOGIES
(2023)
Article
Polymer Science
Mu Sung Kweon, Mahmoud Embabi, Maksim E. Shivokhin, Anvit Gupta, Xuejia Yan, George Pehlert, Patrick C. Lee
Summary: This study investigates the foamability of linear and branched polypropylene (PP) resins using two different melting methods. The results show that at high temperatures, both methods yield similar expansion ratios, with the PP resin with higher strain hardening ratio exhibiting the highest expansion ratio. However, at low temperatures, Method 2 significantly improves the foamability of all resins and results in a more uniform cellular structure over a wider temperature range.
Article
Materials Science, Multidisciplinary
Zhongguo Zhao, Dahang Tang, Shikui Jia, Taotao Ai
Summary: A feasible approach has been proposed to promote the formation of stereocomplex crystal in blends of long-chain branched Poly(L-lactic acid) and Poly(D-lactic acid). The synergistic effect of PDLA and long-chain branches significantly increases the crystalline ability of S-c, leading to more integrated structures and higher nuclei density. This study highlights the importance of hydrogen bond interactions in enhancing the crystallization behavior of the blends.
JOURNAL OF MATERIALS SCIENCE
(2021)
Article
Polymer Science
Cong Yan, De-Fa Hou, Kai Zhang, Ming-Bo Yang
Summary: The molecular weight of poly(D-lactide) (PDLA) and poly(L-lactide) (PLLA) is important for the performance of their blends. In this study, the crystallization and rheological properties of asymmetric PDLA/PLLA blends were studied considering the molecular weight of PDLA. The results showed that an optimal molecular weight of PDLA led to the formation of stereocomplex (SC) crystals and improved viscosity and tensile properties of the blend.
Article
Polymer Science
Deling Li, Congcong Luo, Jun Zhou, Liming Dong, Ying Chen, Guangtian Liu, Shuyun Qiao
Summary: In this study, corn starch was plasticized by glycerol suspension in a twin-screw extruder to obtain PLA/thermoplastic starch/SiO2 composites. The nonisothermal crystallization behavior of PLA in the composites was investigated, and the existence of an interface between PLA and thermoplastic starch was proven. The interfacial binding energy between PLA and thermoplastic starch was found to improve the segmental mobility of PLA at the interface, resulting in increased relative crystallinity.
Review
Polymer Science
Chunyan Luo, Shoujia Li, Minggang Fang, Jianxin Sun, Wei Xiao, Feng Tang, Weixing Chen
Summary: In this study, MWCNTs-g-PLLA was prepared by ring-opening polymerization of L-LA from MWCNTs-OH, and MWCNTs-OH/PLLA(48k) and MWCNTs-g-PLLA/PLLA(48k) composites were successfully obtained. The research findings indicate that the crystallinity and maximum crystallization rate of the blends increase, and the decomposition temperature of the blends increases by over 50 degrees Celsius.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Article
Chemistry, Physical
Meng Xiao, Mengdie Zhang, Haoliang Liu, Boxue Du, Yawei Qin
Summary: This study improves the dielectric performance of polypropylene by long-chain branching modification and adding different nucleating agents, especially at high temperatures. It identifies key factors affecting electrical properties and proposes improvement methods.
Article
Materials Science, Multidisciplinary
Sorapat Niyomsin, Thanphisit Thongsima, Suttinun Phongtamrug, Suwabun Chirachanchai
Summary: Multi-branched polylactide ionomers (mPEI-PLA-COONa) synthesized from multi-branched polyethyleneimine as an additive in polylactide films exhibit significant influence on the film structure and properties.
MRS COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Menglong Xu, Yajie Liu, Yukai Ge, Chongxiang Zhao, Linfeng Wei, Dongdong Hu, Tao Liu, Ling Zhang, Ling Zhao, Chul B. Park
Summary: This study utilized the long-chain branched (LCB) structure in the polyamide 6 (PA6) matrix to prepare low-density microcellular PA6 composite foams with favorable cell morphology. The effects of LCB degree on the rheological behavior, crystallization rate, and gas solubility of CO2 in the PA6 composites were investigated. High-performance PA6 composite foams with small cell size, high cell density, and wide foaming temperature window were successfully obtained through continuous extrusion foaming.
JOURNAL OF SUPERCRITICAL FLUIDS
(2023)
Article
Chemistry, Physical
Seyed Nasibeh Mousavi, Mehdi Entezam, Michael Thomas Mueller, Moslem Tavakol, Hossein Ali Khonakdar
Summary: The influence of irradiation dose, TMPTMA amount, and PP molecular weight on the performance of irradiation technique to create LCB-PP was investigated. Increasing doses or TMPTMA amount led to a reduction in molar mass and an increment in LCBs number, as well as a change in the topology of LCBs. The tensile strength and toughness of irradiated PP samples were controlled by the opposing effects of molar mass reduction and LCBs formation.
RADIATION PHYSICS AND CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Maryam Safari, Nejib Kasmi, Carla Pisani, Vincent Berthe, Alejandro J. Mueller, Youssef Habibi
Summary: This study presents a detailed report on the influence of biobased aliphatic polyesters plasticizers on the nucleation and crystallization of polylactide (PLLA). The addition of plasticizers to PLLA resulted in a decrease in T-g and a significant increase in elongation at break. The nucleation rate from the glassy state of PLLA was also increased by adding the plasticizers, and the overall crystallization rate was accelerated. The incorporation of AdA-based linear polyesters had a positive impact on the crystal growth rate of PLLA spherulites.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2022)
Article
Polymer Science
Stephanie F. Marxsen, Manuel Haussler, Stefan Mecking, Rufina G. Alamo
Summary: This study extends the investigation of polymorphism and crystallization kinetics of aliphatic polyacetals to include different methylene lengths, revealing the significant impact of methylene sequence length on polymorphism and crystallization kinetics. The findings show that the length of methylene groups affects the formation of different crystalline forms and influences the overall crystallization rate of the polyacetals.
Review
Agriculture, Multidisciplinary
Siqing Mao, Ziling Liu, Yuan Tian, Dan Li, Xin Gao, Yanqiong Wen, Tao Peng, Weijun Shen, Dingfu Xiao, Fachun Wan, Lei Liu
Summary: Branched-long-chain monomethyl fatty acids (BLCFA) are consumed daily by humans and have versatile beneficial bioactivities. However, compared to other fatty acids, BLCFA has received less attention, indicating a need for increased research on BLCFA.
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
(2023)
Article
Materials Science, Multidisciplinary
Emre Vatansever, Dogan Arslan, Deniz Sema Sarul, Yusuf Kahraman, Gurbuz Gunes, Ali Durmus, Mohammadreza Nofar
JOURNAL OF MATERIALS SCIENCE
(2020)
Article
Polymer Science
Yusuf Kahraman, Burcu Ozdemir, Volkan Kilic, Yonca Alkan Goksu, Mohammadreza Nofar
Summary: The study found that the multifunctional epoxy Joncryl ADR 4468 chain extender (CE) has a significant impact on the properties of PLA/TPU blend systems, especially when mixed with TPUester, enhancing the impact strength and strain at break values of the blends. Additionally, aPLA reflects the toughening effect of TPUs more efficiently compared to scPLA.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Chemistry, Physical
Deniz Sema Sarul, Dogan Arslan, Emre Vatansever, Yusuf Kahraman, Ali Durmus, Reza Salehiyan, Mohammadreza Nofar
Summary: The study investigated the effect of cellulose nanocrystals (CNCs) on the properties of PLA/PBAT blends. CNCs were found to improve the crystallization behavior and modulus of PLA, but the presence of residual solvent in the blends negatively impacted ductility and impact properties.
COLLOID AND POLYMER SCIENCE
(2021)
Article
Polymer Science
Mohammadreza Nofar, Beril Saadet Yenigul, Burcu Ozdemir, Ceren Yargici Kovanci, Abbas Ghanbari, Amirjalal Jalali
Summary: In this study, rPE based MFCs were developed by incorporating rPET and rPA as reinforcing fibrillar phases at a given weight ratio. The effects of extrusion and injection molding temperatures on fibrillar structure and properties were explored. EnBAGMA and MAH-g-PE acted as compatibilizers, refining the fibrillar structure and significantly influencing mechanical properties.
JOURNAL OF APPLIED POLYMER SCIENCE
(2021)
Article
Engineering, Environmental
Sinan E. Atalay, Betul Bezci, Burcu Ozdemir, Yonca Alkan Goksu, Abbas Ghanbari, Amirjalal Jalali, Mohammadreza Nofar
Summary: The degradation behaviors of amorphous polylactic acid (aPLA) and semicrystalline polylactic acid (cPLA) with similar molecular weights were compared under elevated temperatures and various environmental conditions. The increase in temperature beyond 190 degrees C significantly, but similarly, increased the degradation rate of both aPLA and cPLA samples. Temperature was found to be the most effective parameter in expediting the degradation rate of PLA.
JOURNAL OF POLYMERS AND THE ENVIRONMENT
(2021)
Correction
Chemistry, Physical
Mohammadreza Nofar, Bige Bati, Emine Busra Kucuk, Amirjalal Jalali
JOURNAL OF SUPERCRITICAL FLUIDS
(2021)
Article
Materials Science, Composites
Abbas Ghanbari, Shayan Seyedin, Mohammadreza Nofar, Amir Ameli
Summary: This research focuses on lightweight products for the transportation industry, introducing recycled carbon fibers and elastomers to polypropylene matrix to improve strength and toughness. The addition of 20 wt% recycled carbon fibers led to significant enhancements in heat distortion temperature, tensile strength, and stiffness. Fractography analysis revealed that the presence of fibers predominantly governs the impact resistance characteristics of the composites.
POLYMER COMPOSITES
(2021)
Article
Engineering, Multidisciplinary
Mohammadreza Nofar, Reza Salehiyan, Suprakas Sinha Ray
Summary: This article critically reviews the influence of different nanoparticle localization on the final structure-property relationships of PLA-based blend nanocomposites. The sensitivity of the final performance of the PLA-based blend nanocomposites is explored with regard to the different localizations of different nanoparticles. The recent progress in computer simulation on this topic is also addressed, providing new insight into the design and formulation of advanced PLA-based blend nanocomposites for a wide range of applications.
COMPOSITES PART B-ENGINEERING
(2021)
Article
Engineering, Environmental
Merve Guclu, Yonca Alkan Goksu, Burcu Ozdemir, Abbas Ghanbari, Mohammadreza Nofar
Summary: This study investigates the impact of using a multifunctional epoxide chain extender Joncryl ADR 4468 on the thermal stabilization and rheological properties of recycled PET, especially in blends with PBT. It was found that adding Joncryl and blending with PBT significantly improved the thermal stability and dynamic rheological properties of R-PET, particularly under high temperature testing conditions.
JOURNAL OF POLYMERS AND THE ENVIRONMENT
(2022)
Article
Biochemistry & Molecular Biology
Amirjalal Jalali, Sandra Romero-Diez, Mohammadreza Nofar, Chul B. Park
Summary: This study investigates the manufacturing and characterization of all-polylactide composites using melt spunbond spinning technology. It was found that adding high molecular weight PDLA significantly improves the rheological and mechanical properties of the materials. The SC-PLA samples produced through the spunbond process showed higher tensile modulus and strength, as well as lower shrinkage rates.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2021)
Article
Polymer Science
Yusuf Kahraman, Yonca Alkan Goksu, Burcu Ozdemir, Beril Eker Gumus, Mohammadreza Nofar
Summary: By regulating the composition of PLA/TPU blends compatibilized with multifunctional epoxy-based Joncryl chain extender, this study aimed to improve the impact resistance and ductility of the structures. The addition of Joncryl significantly refined the TPU droplets in all compositions, but only the blends at 75wt/25wt and 65wt/35wt blending ratios showed a dramatic increase in impact strength and ductility. Additionally, rheological experiments and dynamic mechanical analysis confirmed that the compatibilized blends had improved complex viscosity and storage modulus due to increased melt strength and interfacial compatibilization.
JOURNAL OF APPLIED POLYMER SCIENCE
(2022)
Review
Polymer Science
Kerim Eraslan, Clizia Aversa, Mohammadreza Nofar, Massimiliano Barletta, Annamaria Gisario, Reza Salehiyan, Yonca Alkan Goksu
Summary: PHBH is a compostable biobased polymeric material with a wider processing window, better thermal stability, and promising mechanical properties. However, it has received minimal attention due to low availability in the market, high cost, strict confidentiality of polymer manufacturers.
EUROPEAN POLYMER JOURNAL
(2022)
Article
Chemistry, Physical
Yusuf Kahraman, Burcu ozdemir, Beril Eker Gumus, Mohammadreza Nofar
Summary: This study explores the synergistic effects of Cloisite 30B nanoclay and epoxy-based Joncryl chain extender on the PLA/TPU blend. The nano clay refines the droplet morphology at the interface, while the chain extender decreases the TPU droplet size. The presence of nanoclay and the refinement of droplets improve the melt viscoelastic properties, while the addition of chain extender enhances impact strength and ductility.
COLLOID AND POLYMER SCIENCE
(2023)
Article
Polymer Science
Ceren Yargici Kovanci, Mohammadreza Nofar, Abbas Ghanbari
Summary: This study proposes symbiosis approaches to enhance the flame retardancy behavior of polylactide (PLA) composites. The use of phosphorus-based flame retardants in neat PLA samples can achieve the desired flame retardancy, but it doesn't work in PLA composites containing glass fibers due to dripping. By adding chain modifiers, the dripping issue can be resolved and the flame retardancy and mechanical performance of the composites can be further improved.
Article
Green & Sustainable Science & Technology
Deniz Sema Sarul, Dogan Arslan, Emre Vatansever, Yusuf Kahraman, Ali Durmus, Reza Salehiyan, Mohammadreza Nofar
Summary: Polylactide/poly (butylene adipate-co-terephthalate) blend nanocomposites with cellulose nanocrystals were prepared by melt compounding method. The dispersion and localization of CNC and the properties of the blend nanocomposites were affected by different preparation methods. The addition of CNC improved the rheological properties, thermal properties, and elastic modulus of the blends, but the expected improvements in mechanical properties did not occur due to possible residual solvent.
JOURNAL OF RENEWABLE MATERIALS
(2022)
