Bio-based plasticizer and thermoset polyesters: A green polymer chemistry approach

Renewable resource-based polyesters, poly(trimethylene malonate) (PTM) and poly(trimethylene itaconate) (PTI), were synthesized from 1,3-propanediol, malonic acid, and itaconic acid via melt polycondensation using green chemistry principles. Aluminum chloride, a Lewis acid, was used as the catalyst at different reaction temperatures. Chemical structure of PTM and PTI with low dispersities showed the presence of ester and ether bonds. A bimodal molecular weight distribution exists, with the high molecular weight fraction ranging from 22 to 38 kDa while the low molecular weight fraction did not exceed 2.5 kDa. Thermal analysis of PTM showed a Tg ranging between –66 and –41 °C. PTM could be used as a plasticizer for other degradable bioplastics, sensor applications, and drug delivery. PTI, a semi-crystalline thermoset polymer, may be used for production of packaging material, disposable utensils, tableware, indoor furnishings, and more importantly, as a degradable biomaterial for biomedical applications. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43917. © 2016 Wiley Periodicals, Inc

Toughening of poly(lactic acid) with the renewable bioplastic poly(trimethylene malonate)

The aim of this work was to enhance poly(lactic acid)'s (PLA) flexibility and ductility by blending it with another bioplastic. Poly(trimethylene malonate) (PTM), developed as part of this study, was synthesized from 1,3-propane diol and malonic acid via melt polycondensation. Blend films of PLA and PTM were prepared by solvent casting from chloroform. Differential scanning calorimetry and thermogravimetric analysis were used to show shifted phase transitions and a single glass-transition temperature, indicating miscibility of PTM in the blend films. Morphology and mechanical characterizations of the PLA/PTM blend films were performed by atomic force microscopy using a quantitative nanomechanical property mapping mode, tensile testing, and scanning electron microscopy. Miscible blends exhibited Young's modulus and elongation at break values that can significantly extend the usefulness of PLA in commercial applications. The blending of PTM with PLA resulted in films with a 27-fold increase in toughness compared with neat PLA film. © 2014 Wiley Periodicals, Inc.National Science Foundation: CBET-0923474 National Science Foundation: CBET-093349

Nanomechanical properties of poly(trimethylene malonate) and poly(trimethylene itaconate) during hydrolytic degradation

The aim of this work was to evaluate surface mechanical properties of two bioplastics, poly(trimethylene malonate) (PTM) and poly(trimethylene itaconate) (PTI), during hydrolytic degradation. Renewable resource-based PTM and PTI were synthesized from 1,3-propanediol (PDO), malonic acid (MA), and itaconic acid (IA) via melt polycondensation. The hydrolytic degradation was performed in deionized (DI) water (pH 5.4) at room temperature. Morphology and surface mechanical properties at the nanoscale were monitored by atomic force microscopy (AFM) using a quantitative nanomechanical property mapping mode as a function of degradation time. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to show shifted phase transitions depending on the degradation. DSC studies showed hydrolytic degradation induced crystallinity for PTI. After degradation for one week, the degree of crystallinity had significantly increased, and the elastic modulus of PTI had decreased by 58%. PTM was found to be hygroscopic. © 2014 Wiley Periodicals, Inc.National Science Foundation: CBET-0923474 National Science Foundation: CBET-093349

Turkish people's knowledge of cancer and attitudes toward prevention and treatment.

Background. The basic level of cancer knowledge of the population is as important in controlling cancer as diagnostic tools, screening, and new approaches to prevention, early diagnosis, and treatment. Methods. A questionnaire consisting of 24 questions was given to 630 healthy Turkish people to determine their basic knowledge and attitudes regarding cancer. Results. The majority of respondents (78%) were found to have little knowledge of cancer despite the fact that the average level of education of the sample was superior to that of die general population. Educational level was the major predictive factor influencing the basic knowledge and attitudes of the respondents. Conclusion. The overall education of the public as well as the basic level of knowledge of cancer must be improved in cooperation with oncology societies and media in order to overcome the cancer burden in Turkey

Prognostic factors in early glottic carcinoma implications for treatment

Aim: In this study we aimed to determine the prognostic factors affecting local control (LC) in limited glottic carcinoma treated with definitive radiotherapy (FIT)