One-Pot, Bioinspired Coatings To Reduce the Flammability of Flexible Polyurethane Foams

In this manuscript, natural materials were combined into a single “pot” to produce flexible, highly fire resistant, and bioinspired coatings on flexible polyurethane foam (PUF). In one step, PUF was coated with a fire protective layer constructed of a polysaccharide binder (starch or agar), a boron fire retardant (boric acid or derivative), and a dirt char former (montmorillonite clay). Nearly all coatings produced a 63% reduction in a critical flammability value, the peak heat release rate (PHRR). One formulation produced a 75% reduction in PHRR. This technology was validated in full-scale furniture fire tests, where a 75% reduction in PHRR was measured. At these PHRR values, this technology could reduce the fire threat of furniture from significant fire damage in and beyond the room of fire origin to being contained to the burning furniture. This flammability reduction was caused by three mechanismsthe gas-phase and condensed-phase processes of the boron fire retardant and the condensed-phase process of the clay. We describe the one-pot coating process and the impact of the coating composition on flammability

Quantification of nanoparticle release from polymer nanocomposite coatings due to environmental stressing

<p>Certain engineered nanoparticles (ENP) reduce the flammability of components used in soft furnishings (mattresses and upholstered furniture). However, because of the ENP's small size and ability to interact with biological molecules, these fire retardant ENPs may pose a health and environmental risks, if they are released sometime during the life cycle of the soft furnishing. Quantifying the released amount of these ENPs under normal end-use circumstances provides a basis for assessing their potential health and environmental impact. In this article, we report on efforts to identify suitable methodologies for quantifying the release of carbon nanofibers, carbon nanotubes, and sodium montmorillonites from coatings applied to the surfaces of barrier fabric and polyurethane foam. The ENPs released in simulated chewing and mechanical stressing experiments were collected in aqueous solution and quantified using Ultraviolet-Visible and inductively coupled plasma–optical emission spectroscopy. The microstructures of the released ENPs were characterized using scanning electron microscopy. The reported methodology and results provide important milestones to estimate the impact and toxicity of the ENP release during the life cycle of the nanocomposites. To our knowledge, this is the first study of ENP release from the soft furnishing coating, something that can be important application area for fire safety.</p

Patient characteristics.

<p>Patient characteristics.</p

Illustrating the effectiveness of intensity-modulated and image-guided radiotherapy to achieve local control in T4 laryngeal cancer.

<p>The tumor invaded the thyroid cartilage and soft tissue of the neck and produced acute airway obstruction requiring emergency tracheostomy. A repeat CT scan at 40 Gy demonstrated significant shrinkage of the tumor allowing removal of the tracheostomy tube after treatment. The patient is disease-free 45 months after treatment and conserve a normal voice allowing him to work part-time after retirement.</p

Illustrating the potential of Tomotherapy to spare the pharyngeal muscles in a patient who had postoperative chemoradiation for locally advanced base of tongue and bilateral neck metastases.

<p>Even though the right neck was dissected and required radiation of the surgical bed and scars to 63 Gy, the pharyngeal muscles can still be spared from excessive radiation dose. The midline laryngeal block with the split field intensity-modulated radiotherapy technique would have had underdosed the surgical scar and area of the surgical bed located in close proximity to the larynx and the gross lymph nodes on the left side. The patient is in remission 13 month after treatment.</p

Illustration of the effectiveness of Tomotherapy to deliver high radiation dose to the gross tumor and cervical lymph nodes while sparing adjacent normal structures.

<p>The patient had locally advanced base of the tongue cancer (T4) associated with massive cervical metastases (N3) and lung metastases at diagnosis. Following induction chemotherapy which resulted in resolution of the lung metastases, he had concurrent chemoradiation for local control and achieved a complete response of the gross tumor and lymph nodes on post-treatment PET-CT. The lung metastases recurred after treatment and were treated with adjuvant chemotherapy and consolidation stereotactic body radiotherapy. The patient is currently on remission two years after the treatment with no long-term complications except for xerostomia because of low radiation dose to the normal organs. The parotid glands could not be spared because of the close proximity to the gross lymph nodes and areas at high risk for disease.Red line: gross tumor and cervical lymph nodes treated to 70 Gy; green line: area at high risk for disease treated to 63 Gy; pink line: mandibular dose (mean: 56 Gy), gray line: pharyngeal muscles dose (mean: 33.6 Gy); gray-blue line: laryngeal dose (mean: 22.5 Gy); navy blue line: spinal cord dose (max: 39.4 Gy); light blue line: right cochlea dose: (mean: 4.5 Gy); light brown line: left cochlea dose: (mean: 5.3 Gy).</p

Dose distribution to target volume and to critical organs at risk for complications following image-guided radiotherapy for head and neck cancer.

<p>PTV1: target volume receiving 66 to 70 Gy; PTV2: target volume receiving 59.6 to 63 Gy; PTV3: target volume receiving 54 to 56 Gy; Gy: gray.</p

Mean pharyngeal dose (Gy) correlation with dysphagia severity or aspiration reported in the literature.

<p>NA: not assessed; QOL: quality of life.</p

Potential advantages and pitfalls of intensity-modulated radiotherapy (IMRT) and image-guided radiotherapy (IGRT) compared to 3-dimentional conformal radiotherapy (3-D CRT).

<p>Potential advantages and pitfalls of intensity-modulated radiotherapy (IMRT) and image-guided radiotherapy (IGRT) compared to 3-dimentional conformal radiotherapy (3-D CRT).</p

Patient characteristics.

<p>Patient characteristics.</p