Study on low temperature toughness and crystallization behavior of polypropylene random copolymer

2017 ◽  
Vol 37 (7) ◽  
pp. 715-727 ◽  
Author(s):  
Yingchun Li ◽  
Shuai He ◽  
Hui He ◽  
Peng Yu ◽  
Dongqing Wang
Keyword(s):  
Low Temperature ◽  
Crystallization Behavior ◽  
Annealing Treatment ◽  
Random Copolymer ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Polyolefin Elastomer ◽  
The Matrix ◽  
Low Temperature Toughness ◽  
Polymorphic Composition

Abstract This research designed a series of novel approaches aiming to tackle a long-standing problem that is the brittleness of polypropylene (PP) random copolymer (PPR) at low temperature. By introducing polyolefin elastomer (POE), the toughness of PPR was improved; talc improved the stiffness of PPR, low density polyethylene (LDPE) or high density PE (HDPE) improved the low temperature toughness of PPR, and annealing treatment also improved the low temperature toughness of PPR significantly. The addition of dicumyl peroxide (DCP) and triallyl isocyanurate (TAIC) increased its stiffness through the formation of cross-linking networks. Also, the crystallization behavior and morphology were investigated in detail. Differential scanning calorimetry (DSC) results indicated that the adoption of annealing treatment can improve the crystallinity of PPR, while a polarizing microscope revealed that the incorporation of foreign matter can facilitate the crystallization process of the matrix. X-ray diffraction (XRD) tests showed an unchanged polymorphic composition of PPR after introducing different additives, and scanning electron microscopy (SEM) indicated that annealing treatment can enhance interfacial interactions between the matrix and fillers.

scholarly journals Relationship between the Stereocomplex Crystallization Behavior and Mechanical Properties of PLLA/PDLA Blends

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1851
Author(s):  
Hye-Seon Park ◽  
Chang-Kook Hong
Keyword(s):  
Mechanical Properties ◽  
Lactic Acid ◽  
Crystallization Behavior ◽  
Mechanical Analysis ◽  
X Ray Diffraction ◽  
Nucleation Agent ◽  
Scanning Calorimetry ◽  
Nucleation Sites ◽  
Wide Range ◽  
Degree Of Crystallization

Poly (l-lactic acid) (PLLA) is a promising biomedical polymer material with a wide range of applications. The diverse enantiomeric forms of PLLA provide great opportunities for thermal and mechanical enhancement through stereocomplex formation. The addition of poly (d-lactic acid) (PDLA) as a nucleation agent and the formation of stereocomplex crystallization (SC) have been proven to be an effective method to improve the crystallization and mechanical properties of the PLLA. In this study, PLLA was blended with different amounts of PDLA through a melt blending process and their properties were calculated. The effect of the PDLA on the crystallization behavior, thermal, and mechanical properties of PLLA were investigated systematically by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD), polarized optical microscopy (POM), dynamic mechanical analysis (DMA), and tensile test. Based on our findings, SC formed easily when PDLA content was increased, and acts as nucleation sites. Both SC and homo crystals (HC) were observed in the PLLA/PDLA blends. As the content of PDLA increased, the degree of crystallization increased, and the mechanical strength also increased.

Research on compatibility and surface of high impact bio-based polyamide

2021 ◽  
pp. 095400832110055
Author(s):  
Yang Wang ◽  
Yuhui Zhang ◽  
Yuhan Xu ◽  
Xiucai Liu ◽  
Weihong Guo
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Crystallization Behavior ◽  
High Impact ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

The super-tough bio-based nylon was prepared by melt extrusion. In order to improve the compatibility between bio-based nylon and elastomer, the elastomer POE was grafted with maleic anhydride. Scanning Electron Microscopy (SEM) and Thermogravimetric Analysis (TGA) were used to study the compatibility and micro-distribution between super-tough bio-based nylon and toughened elastomers. The results of mechanical strength experiments show that the 20% content of POE-g-MAH has the best toughening effect. After toughening, the toughness of the super-tough nylon was significantly improved. The notched impact strength was 88 kJ/m2 increasing by 1700%, which was in line with the industrial super-tough nylon. X-ray Diffraction (XRD) and Differential Scanning Calorimetry (DSC) were used to study the crystallization behavior of bio-based PA56, and the effect of bio-based PA56 with high crystallinity on mechanical properties was analyzed from the microstructure.

Thermal Stability and Crystallization Behavior of PP/Organoclay Phase Change Composites

2013 ◽  
Vol 785-786 ◽  
pp. 123-126
Author(s):  
Ying Ye ◽  
Kun Yan Wang ◽  
Ge Chang ◽  
Qian Ying Jiang
Keyword(s):  
Thermal Stability ◽  
Phase Change ◽  
Crystallization Behavior ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Nucleation Agent ◽  
Scanning Calorimetry ◽  
Blending Method ◽  
Phase Change Composites ◽  
Change Material

Polypropylene/organoclay modified by dodecanol phase change material were prepared by melt blending method. The thermal stability and crystallization behavior was studied by thermogravimetry (TG), differential scanning calorimetry (DSC), and X-ray diffraction (XRD). TG results indicated the window of processing of PP could be improved by adding small amount organoclay modified by dodecanol to the blend. DSC showed the organoclay modified by dodecanol affected the crystallization behavior of PP as heterogeneous nucleation agent. XRD results show that the organoclay modified by dodecanol does not change the crystal structure in the blends but only decrease the intensity of the diffraction peak.

The non-isothermal crystallization behavior of polyamide 6 and polyamide 6/HDPE/MAH/L-101 composites

2019 ◽  
Vol 39 (2) ◽  
pp. 124-133 ◽  
Author(s):  
Bingxiao Liu ◽  
Guosheng Hu ◽  
Jingting Zhang ◽  
Zhongqiang Wang
Keyword(s):  
Crystallization Kinetics ◽  
Isothermal Crystallization ◽  
Crystallization Behavior ◽  
Isothermal Condition ◽  
Crystallization Rate ◽  
Polyamide 6 ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Analysis And Design ◽  
Processing Techniques

AbstractStudy of the crystallization kinetics is particularly necessary for the analysis and design of processing operations, especially the non-isothermal crystallization behavior, which is due to the fact that most practical processing techniques are carried out under non-isothermal conditions. The non-isothermal crystallization behaviors of polyamide 6 (PA6) and PA6/high-density polyethylene/maleic anhydride/2,5-dimethyl-2,5-di(tert-butylperoxy)hexane (PA6/HDPE/MAH/L-101) composites were investigated by differential scanning calorimetry (DSC). The crystallization kinetics under non-isothermal condition was analyzed by the Jeziorny and Mo equations, and the activation energy was determined by the Kissinger and Takhor methods. The crystal structure and morphology were analyzed by wide-angle X-ray diffraction (WXRD) and polarized optical microscopy (POM). The results indicate that PA6/HDPE/MAH/L-101 has higher crystallization temperature and crystallization rate, which is explained as due to its heterogeneous nuclei.

scholarly journals Alumina Extraction from Coal Fly Ash via Low-Temperature Potassium Bisulfate Calcination

Minerals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 585 ◽  
Author(s):  
Chunbin Guo ◽  
Jingjing Zou ◽  
Shuhua Ma ◽  
Jianlin Yang ◽  
Kehan Wang
Keyword(s):  
Fly Ash ◽  
Low Temperature ◽  
Extraction Efficiency ◽  
Coal Fly Ash ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Increasing Demand ◽  
Technology Effects ◽  
Best Fit

Owing to the depletion of bauxite and increasing demand for alumina, calcination methods for extracting alumina from coal fly ash (CFA) were developed. However, these methods have disadvantages such as the need for high temperatures and the emission of toxic gases. Hence, in this study, Al2O3 was extracted from CFA via low-temperature potassium bisulfate calcination technology. Effects of the potassium bisulfate amount, calcination temperature, and calcination time on the alumina extraction efficiency were investigated using X-ray diffraction, thermal gravimetry, scanning electron microscopy, differential scanning calorimetry, and energy-dispersive spectroscopy. It was found that this technique could recover alumina efficiently, and potassium bisulfate significantly contributed to the degradation of mullite and corundum phases. Al2O3 in CFA was converted into soluble K3Al(SO4)3. With a KHSO4/Al2O3 molar ratio of 7:1, calcining temperature of 230 °C, and calcining time of 3 h, the alumina extraction efficiency reached a maximum of 92.8%. The Avrami–Erofeev equation showed the best fit with the kinetic data for the low-temperature calcination of CFA with KHSO4. The activation energy was 28.36 kJ/mol.

Erucamide-Nanoclay Systems Obtained by Intercalation Process

2017 ◽  
Vol 899 ◽  
pp. 36-41 ◽  
Author(s):  
Josiane R. Silvano ◽  
J.M.M. Mello ◽  
Lucinao Luiz Silva ◽  
Humberto Gracher Riella ◽  
Márcio Antônio Fiori
Keyword(s):  
Differential Scanning Calorimetry ◽  
Reaction Medium ◽  
Film Surface ◽  
Polymeric Materials ◽  
Polymeric Films ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Intercalation Process ◽  
The Matrix

A major challenge in the manufacture of films for polymeric packaging is the definition and setting of the friction coefficient (FCO) for the film surfaces. The FCO values are established with the incorporation of additives during the processing of the polymeric films. But, the homogenization of these additives in the polymeric matrix is very difficult. The additives have different polarity that the matrix polymeric and not are mixable. So, these additives migrate for the surface of the polymeric films easily. Several molecules are used as sliding additives, but among the most efficient are the amides molecules, highlighting the erucamide. This molecule promotes the decrease of the FOC but due its quick migration for the polymeric film surface provides numerous problems for the manufacture of the polymeric packaging and during its application as the product. In this work a nanocomposite (MMT-ERU) was obtained by an intercalation process to improve the compatibility between the polymeric materials and the erucamide molecules. The results shown in this work refers to the studies about the intercalation processes of the erucamide molecules into nanoclays (montmorillonite) to obtain the nanocomposite MMT-ERU. The effect of the temperature and the percentage of the nanoclay in the intercalation processes were studied. The results of x-ray diffraction and differential scanning calorimetry shown that erucamide molecules were intercalated in the nanoclay structures and that intercalation efficiency depends positively of the temperature and percentage amount of the nanoclay in the reaction medium.

Low Temperature Crystallization of Sputter-Deposited TiNi Films

2012 ◽  
Vol 78 ◽  
pp. 81-86 ◽  
Author(s):  
Yoichi Kishi ◽  
Noriaki Ikenaga ◽  
Noriyuki Sakudo ◽  
Zenjiro Yajima
Keyword(s):  
Low Temperature ◽  
Substrate Temperature ◽  
Ion Irradiation ◽  
Electrical Power ◽  
Annealing Treatment ◽  
Rf Magnetron Sputtering ◽  
X Ray Diffraction ◽  
Diffraction Profile ◽  
Double Beam ◽  
Sputter Deposited

We have found that deposited film can be crystallized without the post-annealing treatment but with the simultaneous ion-irradiation during sputter-deposition at very low substrate temperature. The present paper reviews the low temperature crystallized TiNi films deposited by the above technique. An RF magnetron sputtering apparatus equipped with separate confocal sources as well as with a heating and ion-irradiating system for substrates was used to make the films crystalline. Without using the ion-irradiating system, the films deposited on ambient-temperature substrate have been amorphous. However, crystallized film is deposited even at 353 K of substrate temperature with using the system. Appropriate ion-irradiation is considered to be help to crystallize the film at low substrate temperature. Broad and doublet X-ray diffraction profile of the film, which was diffracted from B19’ and/or R phase, was recorded between 42 degree to 45 degree in 2 theta. The crystallized film deposited on a polyimide sheet was cut into the shape of a double-beam cantilever and the ends of the two beams were connected to an electrical power supply. The cantilever shows a repeatable two-way motion by electrical cycle of 0.1 Hz at room temperature.

Crystallization Behavior and Crystal Morphology of PP/POEg Blends

2014 ◽  
Vol 941-944 ◽  
pp. 1253-1256
Author(s):  
Kun Yan Wang
Keyword(s):  
Crystallization Behavior ◽  
Crystal Morphology ◽  
Optical Microscope ◽  
Melt Blending ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Blending Method ◽  
Differential Scanning Colorimetry ◽  
Poly Ethylene ◽  
Spherulitic Structure

Polypropylene (PP)/Maleic anhydride grafted poly (ethylene-octene) (POEg) were prepared by melt blending method. The crystallization behavior and crystal morphology were studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD), and polarzing optical microscope (POM). Differential scanning colorimetry (DSC) experiments showed that the melting point and crystallization point decreased when POEg added to the blend. XRD results show that the POEg not change the crystal structure in the blends but only decrease the intensity of the diffraction peak. The spherulitic structure could also observed when added POEg to the matix of PP, but the shape of the spherulites distorted.

The Effect of Uniaxial Stretching on the Crystallization Behaviors of Polylactic Acid Film

2011 ◽  
Vol 418-420 ◽  
pp. 625-628 ◽  
Author(s):  
Hui Li Xie ◽  
Kai Guo ◽  
Jin Zhou Chen ◽  
Wan Jie Wang ◽  
Ming Jun Niu ◽  
...  
Keyword(s):  
Polylactic Acid ◽  
Crystallization Behavior ◽  
Crystal Form ◽  
Stretch Ratio ◽  
Uniaxial Tensile ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Uniaxial Stretching ◽  
X Ray ◽  
Stretching Ratio

Abstract. The effect of uniaxial stretching of different stretching ratio at 80 °C, 90°C, 100°C, 110 °C and 120°C on the crystallization behavior of polylactic acid (PLA) film was investigated by using differential scanning calorimetry (DSC), wide-angle X-ray diffraction (XRD) and polarizing microscope (POM). The results showed that the crystallinity of PLA film was improved via uniaxial tensile orientation and increased with increasing stretch ratio, and the crystallinity of PLA film reached the maximum under the conditions of 90°C and stretching ratio 300%. Stretched PLA films show α crystal form. The spherulites deform to ellipsoids after stretching.

Crystallization Properties of Nucleated Poly(lactic acid)

2012 ◽  
Vol 549 ◽  
pp. 322-326 ◽  
Author(s):  
Yong Chen ◽  
Qiang Dou
Keyword(s):  
Lactic Acid ◽  
Crystallization Behavior ◽  
Polarized Light ◽  
Nucleating Agent ◽  
Poly Lactic Acid ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Crystallization Properties ◽  
Melting And Crystallization

The effect of a nucleating agent (NT-C) on the crystallization behavior of poly(lactic acid) (PLA) was studied. The melting and crystallization behavior and spherulitic morphology of the nucleated PLA were investigated by means of differential scanning calorimetry (DSC), wide angle X-ray diffraction (WAXD) and polarized light microscopy (PLM). It is found that the crystallization temperature and crystallinity increase, the spherulitic size decrease for the nucleated PLA. But the crystal structure of the nucleated PLA is not changed.

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