High Flow TPO Compounds Containing Branched EPDM Modifiers

1998 ◽  
Vol 71 (4) ◽  
pp. 778-794 ◽  
Author(s):  
N. Dharmarajan ◽  
L. G. Kaufman
Keyword(s):  
Impact Resistance ◽  
Ductile Failure ◽  
High Flow ◽  
Raw Material ◽  
Resin Matrix ◽  
Molecular Architecture ◽  
Polybutylene Terephthalate ◽  
Ethylene Propylene ◽  
Thermoplastic Olefin ◽  
Long Chain

Abstract Polymer blends of ethylene-propylene elastomers and polypropylene plastics, referred to as thermoplastic olefins, are finding increasing use in automotive applications. The combination of attractive mechanical properties, low raw material cost and recyclability make these materials ideal substitutes for expensive engineering thermoplastics (polycarbonate/polybutylene terephthalate alloys) and nonrecyclable polyurethane systems. The primary application is in automotive bumper fascia. This paper describes the addition of long chain branched ethylene-propylene elastomers in thermoplastic olefin compounds containing a high flow polypropylene resin matrix. In such compounds, the modifier molecular architecture plays an important role in impact toughening. The results clearly indicate that linear modifiers such as traditional ethylene-propylene copolymers are ineffective in impact toughening, while long chain branched polymers provide enhanced impact resistance with a ductile failure mode in high flow polypropylenes.

Role of molecular architecture in interfacial self-adhesion of polyethylene films

2017 ◽  
Vol 33 (3) ◽  
pp. 235-261 ◽  
Author(s):  
Zahra Najarzadeh ◽  
Abdellah Ajji
Keyword(s):  
Molecular Weight ◽  
Adhesion Strength ◽  
Film Surface ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Molecular Architecture ◽  
Melt Temperature ◽  
Long Chain ◽  
Long Chain Branch ◽  
Chain Branch

The influence of molecular architecture on interfacial self-adhesion above polyethylene film melt temperature was examined in this study. The investigated molecular structures include molecular weight (Mw), molecular weight distribution, long chain branch amount and distribution and short chain branch among and along polyethylene chains. The long chain branches concentration was quantified using gel permeation chromatography and short branches concentration using nuclear magnetic resonance techniques. The adhesion strength was measured immediately after melt bonding using a T-Peel test. The results showed that increasing Mw resulted in higher adhesion strength in linear metallocene ethylene α-olefins. Low long chain branch concentrations hinder reptation motion and diffusion, and result in lower adhesion strength. Low density polyethylene with highly branched chains yielded very low self-adhesion. A drastic difference in adhesion strength between metallocene and conventional linear low density polyethylene is attributed to homogeneity versus heterogeneity of composition distribution. The low interfacial self-adhesion in conventional polyethylene was concluded to be due to enrichment of highly branched low molecular weight chains at the film surface. These segregated chains at the interface diffuse before the high molecular weight chains located in the bulk.

Mechanical and Thermal Properties of Siloxane Reinforced Biphenyldiol Formaldehyde Resin Curing Epoxy Resin Composites

2014 ◽  
Vol 936 ◽  
pp. 3-7
Author(s):  
Shi Hui Chen ◽  
Jun Gang Gao ◽  
Hong Zhe Han ◽  
Chao Wang
Keyword(s):  
Epoxy Resin ◽  
Impact Resistance ◽  
Resin Matrix ◽  
Formaldehyde Resin ◽  
Mechanical And Thermal Properties ◽  
Reinforced Composites ◽  
Interfacial Bonding Strength ◽  
Resin Curing ◽  
Degradation Properties ◽  
The Impact

In order to modify the properties of the epoxy composites, an alkali catalyzed biphenyldiol formaldehyde resin (BPFR) was synthesized and used to cure epoxy resin (ER). γ-Glycidoxypropyl trimethoxysilane (KH-560) was used as a reinforcer of the composites. Laminates of the BPFR/ER fiberglass reinforced composites with different (KH-560) contents were prepared. The influence of the KH-560 content on the glass transition temperature (Tg) and thermal degradation properties of the composites was researched by dynamic mechanical analyzer (DMA) and thermogravimetric analysis (TG). The mechanical, electrical properties of the composites were determined. The results showed that the interfacial bonding strength between resin matrix and fiberglass can be efficiently improved with the presence of KH-560. When the ratio of BPFR and ER is 3 : 7, the content of KH-560 is 5 ~7 wt%, the impact resistance of the fiberglass reinforced composites is 61.35~78.59 kJ/m2, the tensile resistance is 150.37~162.54 MPa, which are all 30 % higher than that of no added; The dielectric constant ε and dielectric loss tanδ of the composites is between 0.50~0.68 and between 0.008~0.01, respectively.

scholarly journals A Long-Chain Alkylation of Dialdehyde Starch to Improve Its Thermal Stability and Hydrophobicity

2016 ◽  
Vol 2016 ◽  
pp. 1-7
Author(s):  
Jiang Zhu ◽  
Zhaodong Wang ◽  
Haitao Ni ◽  
Xiang Liu ◽  
Jian Ma ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Reaction Time ◽  
Reaction Temperature ◽  
Orthogonal Experiment ◽  
Raw Material ◽  
Molar Ratio ◽  
Dialdehyde Starch ◽  
Hydrophobic Properties ◽  
Feed Composition ◽  
Long Chain

Hydrophobic dialdehyde starch (HDAS) was synthesized by dialdehyde starch (DAS) and eighteen-alkyl primary amine as the raw material in DMSO. The effect of the reaction conditions on the yield of HDAS was investigated such as catalyst content, reaction temperature, reaction time, and the in-feed molar ratio of -CHO/-NH2. Moreover, the optimized test parameters were obtained by conducting orthogonal experiment. The molecular structure and the morphology of HDAS were characterized via Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). And the thermal stability and the hydrophobic properties of HDAS were investigated by thermal gravimetric analyzer (TG) and the hydrophobic testing. The results indicate that the yield of HDAS is the highest up to 44.21%, with feed composition 1 : 0.9, reaction temperature 40°C, reaction time 8 h, and acetic acid content 3%. And the introduction of the long-chain alkyl groups into the DAS backbones will ameliorate efficaciously the thermal stability and the hydrophobic properties of DAS, which almost has no effect on the DAS particle size.

scholarly journals Fatty acids stability in goat yoghurt

2019 ◽  
Vol 49 (7) ◽  
Author(s):  
Lenka Pecová ◽  
Eva Samková ◽  
Oto Hanuš ◽  
Lucie Hasoňová ◽  
Jiří Špička
Keyword(s):  
Fatty Acids ◽  
Dairy Products ◽  
Nutritional Value ◽  
Dairy Product ◽  
Goat Milk ◽  
Raw Material ◽  
Major Influence ◽  
Milk Processing ◽  
Fa Composition ◽  
Long Chain

ABSTRACT: Evaluation of fatty acids (FAs) stability in dairy products undergoing technological milk processing is important for subsequent determinations of nutritional value. The aim of the study was to assess FA composition in milk and its dairy product and to explore differences in the FA profile found in yoghurt compared to raw material (goat milk). In the present study, a reduced proportion of volatile FAs (VFA) that cause “goat flavor” was reported in goat yoghurt in comparison to the FA profile of milk. Conversely, an increase of medium-chain as well as beneficial long-chain and unsaturated FAs (UFA) was reported in yoghurt compared with milk. In all cases, the differences in the FA composition between milk and yoghurt were not significant; therefore, it was found that manufacturing of yoghurt had no major influence on FA composition.

scholarly journals Quantitative sediment source attribution with compound-specific isotope analysis in a C3 plant-dominated catchment (central Switzerland)

2016 ◽  
Vol 13 (5) ◽  
pp. 1587-1596 ◽  
Author(s):  
Christine Alewell ◽  
Axel Birkholz ◽  
Katrin Meusburger ◽  
Yael Schindler Wildhaber ◽  
Lionel Mabit
Keyword(s):  
Agricultural Land ◽  
Isotope Analysis ◽  
High Flow ◽  
Sediment Source ◽  
Sediment Sources ◽  
Source Attribution ◽  
C3 Plant ◽  
Compound Specific Isotope Analysis ◽  
Central Switzerland ◽  
Long Chain

Abstract. As sediment loads impact freshwater systems and infrastructure, their origin in complex landscape systems is of crucial importance for sustainable management of agricultural catchments. We differentiated the sediment source contribution to a lowland river in central Switzerland by using compound-specific isotope analysis (CSIA). We found a clear distinction of sediment sources originating from forest and agricultural land use. Our results demonstrate that it is possible to reduce the uncertainty of sediment source attribution in: (i) using compound content (in our case, long-chain fatty acids; FAs) rather than soil organic matter content to transfer δ13C signal of FAs to soil contribution and (ii) restricting the investigation to the long-chain FAs (> C22 : 0) not to introduce errors due to aquatic contributions from algae and microorganisms. Results showed unambiguously that during base flow, agricultural land contributed up to 65 % of the suspended sediments, while forest was the dominant sediment source during high flow. This indicates that connectivity of sediment source areas within the river changes between base and high flow conditions. Uncertainty, which might occur in complex, large-scale studies due to undetected source attribution and/or CSSI signature degradation, is low because of limited data complexity in our study (i.e., two–three sources and two tracers). Our findings are the first published results highlighting (i) significant differences in compound-specific stable isotope (CSSI) signature of sediment sources from land uses dominated by C3 plant cultivation and (ii) the use of these differences to quantify sediment contribution to a small river.

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