The role of m-phenylenedimaleimide in reactive processing of poly(propylene)/magnesium hydroxide composites, 2. Effect of processing temperature and composite formulation on rheological properties

In the first part of this series of papers, the effect of m-phenylenedimaleimide (BMI), processing temperature and a lubricant (a fatty acid ester/amide blend) on the mechanical properties of poly(propylene)/magnesium hydroxide composites was investigated. The second part focuses on the effect of the same formulation and processing variables on the rheological properties of the composites. In these investigations a three-factorial experimental design has been used to optimize the product composition. It has been found that BMI addition is detrimental to melt flow properties. This problem can be overcome by addition of a lubricant without unduly compromising the improved mechanical properties afforded by BMI. On the basis of calculated responses, composite formulation was optimized to obtain materials with improved mechanical properties and acceptable processing characteristics.     

The role of m-phenylenedimaleimide in reactive processing of poly(propylene)/magnesium hydroxide composites. 1. Effect of processing temperature and composite formulation on mechanical properties

The role of the interface modifier, m-phenylenedimaleimide (BMI), and a lubricant (a mixture of fatty acid amides and esters) in the reactive processing of poly(propylene)/magnesium hydroxide-based composites has been studied. In this investigation process a three-factorial experimental design has been used as a tool to investigate the simultaneous effect of interface modifier, lubricant and processing temperature, with respect to mechanical properties. All of the latter variables were found to influence the properties of the composites. It was found that the significant improvement in mechanical properties (ca. 100%, relative to unmodified composite) afforded by BMI was not, with correct formulation, offset by the detrimental effect associated with the lubricant. The effect of temperature was complex but appeared to be strongly influenced by the BMI level.     

Evaluation of the Properties of PHB Composite Filled with Kaolin Particles for 3D Printing Applications Using the Design of Experiment

In the presented work, poly(3-hydroxybutyrate)-PHB-based composites for 3D printing as bio-sourced and biodegradable alternatives to synthetic plastics are characterized. The PHB matrix was modified by polylactide (PLA) and plasticized by tributyl citrate. Kaolin particles were used as a filler. The mathematical method “Design of Experiment” (DoE) was used to create a matrix of samples for further evaluation. Firstly, the optimal printing temperature of the first and upper layers was determined. Secondly, the 3D printed samples were tested with regards to the warping during the 3D printing. Testing specimens were prepared using the determined optimal printing conditions to measure the tensile properties, impact strength, and heat deflection temperature (HDT) of the samples. The results describe the effect of adding individual components (PHB, PLA, plasticizer, and filler) in the prepared composite sample on the resulting material properties. Two composite samples were prepared based on the theoretical results of DoE (one with the maximum printability and one with the maximum HDT) to compare them with the real data measured. The tests of these two composite samples showed 25% lower warping and 8.9% higher HDT than was expected by the theory.     

Optimization of the properties of chitosan lactate/hyaluronan film

Polyelectrolyte complexes represent attractive class of polymer‐based materials, finding an irreplaceable role in biomaterial preparation for tissue engineering or drug delivery beads. Mechanical properties, physical properties, and enzymatic degradation of the film prepared from chitosan lactate/hyaluronan polyelectrolyte complex, crosslinked with starch dialdehyde derivatives, were studied to optimize its composition. This work represents an example demonstrating how a minor modification of the modified complex composition changes final properties of the prepared film and emphasizes enormous variations in complex formation by crosslinking. To obtain sufficiently useful information, experimental design was employed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 1413–1419, 2006     

Domain-specific entity extraction from noisy,unstructured data using ontology-guided search

Domain-specific knowledge is often recorded by experts in the form of unstructured text. For example, in the medical domain, clinical notes from electronic health records contain a wealth of information. Similar practices are found in other domains. The challenge we discuss in this paper is how to identify and extract part names from technicians repair notes, a noisy unstructured text data source from General Motors’ archives of solved vehicle repair problems, with the goal to develop a robust and dynamic reasoning system to be used as a repair adviser by service technicians. In the present work, we discuss two approaches to this problem. We present an algorithm for ontology-guided entity disambiguation that uses existing knowledge sources, such as domain-specific taxonomies and other structured data. We illustrate its use in the automotive domain, using GM parts ontology and the unit structure of repair manuals text to build context models, which are then used to disambiguate mentions of part-related entities in the text. We also describe extraction of part names with a small amount of annotated data using hidden Markov models (HMM) with shrinkage, achieving an f-score of approximately 80%. Next, we used linear-chain conditional random fields (CRF) in order to model observation dependencies present in the repair notes. Using CRF did not lead to improved performance, but a slight improvement over the HMM results was obtained by using a weighted combination of the HMM and CRF models.