کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
692964 889858 2012 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Multiphase coatings from complex radiation curable polyurethane dispersions
موضوعات مرتبط
مهندسی و علوم پایه مهندسی شیمی تکنولوژی و شیمی فرآیندی
پیش نمایش صفحه اول مقاله
Multiphase coatings from complex radiation curable polyurethane dispersions
چکیده انگلیسی

The waterborne nature of radiation curable polyurethane dispersions largely respond to the current environmental concerns and do not require any additional coalescent since the film formation (drying) and hardening (photo-curing) take place in distinct steps. It is possible to design aqueous dispersions with distinct polymer particle populations resulting in micro-structured coatings with optimized properties over a wide range of curing conditions. Mixed dispersions based on hard and soft acrylated polyurethane particles were used as model systems for the present study. The minimum film formation temperature has been investigated as a function of the hard:soft polymer ratio. The elastic modulus of the dry coatings shows a reinforcing effect consistent with the inclusion of hard domains in a soft continuous matrix. However, the level of reinforcement is not properly predicted by the usual mechanical models and it is qualitatively accounted for by assuming a composition gradient (interphase) between the hard domains and the matrix. The multiple-phase structure was clearly established by Atomic Force Microscopy in agreement with thermal analysis data. Furthermore the local nanoscale mechanical properties were mapped using a new imaging mode based on real-time force–distance curve analysis. Finally, the coatings prepared using this multiple-phase pattern present a clear benefit over conventional homogeneous coatings by offering an improved balance of chemical and mechanical resistance in pigmented systems applied on melamine-coated MDF panels.


► Dispersions from soft and hard urethane particles provide unique performance coatings.
► A new imaging from peak-force tapping-mode AFM displays the local phase morphology.
► A compositional inter-phase around hard inclusions boosts the mechanical properties.
► A three-phase model qualitatively predicts the Young's modulus dependence.
► An excellent pigmented coating performance is obtained after radiation curing.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Progress in Organic Coatings - Volume 75, Issue 4, December 2012, Pages 560–568
نویسندگان
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