Characterization of a Paint-PMMA Polymer Blend
Jordan Asseo Emily Danilak [email protected] [email protected]
Elizabeth Gray Nicholas Ritter [email protected] [email protected]
Ammer Soliman [email protected]
Abstract waste paint constitutes the single largest volume of material collected by local The disposal of waste latex-based government household hazardous waste paint poses significant financial and collection programs.1 Of this estimated environmental problems in the United figure, approximately 50% of this unused States. A potential solution is to recycle paint is latex-based paint.1 latex paint by removing the water from The disposal of latex paint poses the paint, and melt-processing it with financial and environmental poly(methyl methacrylate) (PMMA) to problems. Of all household hazardous create an immiscible polymer wastes, paint is the most expensive blend. Prior research shows that a 20-80 material that local governments must weight percent (wt %) composition ratio manage and discard.2 The cost for a of latex paint to PMMA provides similar municipality to properly collect and mechanical behavior in tension as dispose of waste paint is at least $8 per PMMA. For this study, a novel melt- gallon.1 If all paint, including latex and processing method that mixes oil paint, were properly managed by all components and fabricates parts in a municipalities, it would cost an estimated single step was used to prepare 20-80 wt total of $275 million per year.1 Proper % Paint-PMMA blends. The flexural, latex paint disposal is not only a costly impact, thermal, and structural properties affair for local governments, but also a were characterized and compared with painstaking process for neet PMMA. Results indicate that Paint- consumers. Liquid latex paint cannot be PMMA is a viable, less expensive put into garbage trucks because of the risk alternative to PMMA while also of equipment contamination and must be mitigating the disposal of waste latex placed outside to dry prior to paint. disposal.3 While the paint is drying, it is necessary to keep all children, pets, and 1 1. Introduction wildlife away from it. The drying process requires time and effort, and local Collecting and managing waste governments attribute instances of improper disposal to the difficulty of the paint is a significant problem facing the 2 United States. With an estimated 17 to 35 drying process. million gallons of paint unused each year, The issue of latex paint also lies in together through covalent bonding to its harmful effects on the form long polymer chains with high environment. While the U.S. has been molecular weights.4 Depending on the shifting away from using notoriously structure, polymers can be classified as environmentally harmful oil-based paints either thermoplastic or thermoset. and toward latex paint, latex paint is still Thermoplastic polymers, such as PMMA an environmental concern.1 The most and latex, have covalent bonding along pressing environmental concern the main chains and secondary bonding associated with latex paint is its improper between chains. Thermoplastic polymers disposal into bodies of water. Aquatic life are recyclable because they are able to be is exposed to latex paint through the melted, cooled into a desired shape, spilling and dumping of the paint into melted again, and re-shaped over many storm drains.1 According to the cycles. Thermoset polymers, on the California Department of Fish and Game, other hand, form crosslinks between “latex paints, having both toxic polymer chains and degrade when constituents as well as high reheated.5 Accordingly, thermoset concentrations of pigments with polymers can only be formed once and increased turbidity can be extremely are therefore not recyclable. deleterious to fish and aquatic life and The thermoplastic nature of both must not be allowed to enter waters of the PMMA and latex allows for them to be State or be placed at a location where it melt-processed into an immiscible can enter such waters.”1 polymer blend. An immiscible polymer Since the burden of disposing of blend is a combination of two or more latex paint has proven to be very polymers that are physically, rather than inefficient and a significant deterrent for chemically, mixed together and remain as consumers, recycling latex paint could distinct phases.6 Therefore, the two avoid many of these harmful effects.1 The polymers form a mechanical bond purpose of this research project is to test between one another. This contrasts with if dried latex paints can be mechanically miscible polymer blends, in which two mixed with the thermoplastic polymer polymers are mixed together to form a poly(methyl methacrylate) (PMMA) in chemically homogeneous blend with only order to form a functional immiscible one phase present. A miscible polymer polymer blend that shares similar blend generally has properties properties with PMMA. Ideally, this intermediate between the two original could eventually bypass the challenges polymers. The advantage of an associated with waste latex paint immiscible polymer blend is that under management. ideal conditions of mixture composition and processing methods, its mechanical 2. Background properties can actually supersede those of the original polymers.7 Achieving Polymers are macromolecules superior mechanical properties requires comprised of a carbon backbone and dispersive and distributive mixing and represented by a unique repeat unit.4 good interfacial adhesion between the These repeating units, which are groups components so that applied stresses may of atoms centered around one or more be efficiently transferred between the two carbon atoms, are chemically linked phases.7 There are several important deformation represents the onset of mechanical and thermal properties that material failure. Ductility is the measure must be compared when evaluating of the degree of plastic deformation that a polymers due to the varied behavior they material can sustain before it fractures.8 exhibit under different conditions of Polymers can be characterized as brittle if temperature and load.8 For instance, the polymer cannot undergo a significant when considering the mechanical amount of plastic deformation without properties of a material, the maximum fracturing or ductile if it can undergo a load it can withstand at room temperature significant amount of plastic deformation must be determined. The external force, without fracturing. or load, acting on a material is known as Polymers can be further stress. When a stress is applied to a characterized as amorphous, semi- material, the material sustains crystalline, or crystalline based on the deformation, known as strain. Stress and structure and interactions between their strain are often coupled together to form polymer chains.8 Amorphous polymers, stress-strain curves.8 Stress-strain curves such as PMMA and latex paint, have a are used to determine the amount of strain highly randomized molecular a material undergoes when a certain structure. As a result, they often exhibit magnitude of stress is applied to it and to viscoelastic behavior at intermediate determine the point at which the material temperatures.8 As temperature decreases, can no longer sustain a load, fracturing as amorphous polymers enter a glassy phase a result.4 The modulus of elasticity, or where the modulus of their stress-strain Young’s Modulus (E), demonstrates the curve approaches zero.4 As temperature relation between stress and strain by increases, the material becomes soft measuring a material’s resistance to enough for the chains to freely flow. At elastic deformation. A material’s this temperature, modulus is negligible.4 modulus can be determined by The significance of this behavior is that calculating the slope of its stress-strain PMMA experiences instantaneous elastic curve in the elastic region. Thus, the strain in response to stress, but recovers stiffer the material, the higher the this deformation in a time-dependent, modulus. The equation to measure viscous manner. Although the phase 푠푡푟푒푠푠 modulus of elasticity is: 퐸 = . 9 transition from glassy solid to viscous 푠푡푟푎푖푛 liquid is not immediately distinguishable, All polymers experience a certain the temperature that divides the two states amount of elastic deformation before is referred to as the glass transition reaching a yield point. Elastic temperature (denoted as T ).4 deformation refers to the temporary g Crystalline polymers have a much deformation that a material experiences greater degree of order than amorphous that will not permanently alter the shape polymers. In the solid state, the of a material, while plastic deformation molecules line up in a repeating array refers to the permanent and non- across the entire structure. Thus, there is recoverable change in the form of a a clear distinction between the solid and material.8 The yield point on the stress- liquid states of crystalline polymers, as strain curve is the point at which elastic the molecules completely break away deformation ends and plastic deformation from their crystal structures in the liquid begins. Because plastic deformation is state and the polymer chains lose their irreversible, the start of plastic ordered array. The melting point is the enclosures to optical fibers for name given to the temperature at which telecommunication and endoscopy.12 the phase change occurs. Semi- PMMA was selected for this crystalline polymers share properties of paint-polymer composite because it both amorphous and crystalline shares many similar chemical properties polymers. Some portions of the polymer with latex paint, is relatively cheap, and are amorphous, while others are is easy to process.4, 11 The PMMA used in crystalline in scattered areas. This means this project was PMMA, Atluglas that semi-crystalline polymers have both V045100. a glass transition temperature and a melting point.8 2.3 Paint-PMMA Mixture In this project, latex paint was 2.1 Latex Paint mixed with PMMA in a 20-80 wt % Latex paint is the most popular ratio. This composition ratio was type of paint, representing over 85% of selected based on evaluation of previous paint sales in the United research done on this topic, in which it States.10 Compared to its counterpart, oil- was concluded that latex paint could be based paint, latex paint accounts for 89% blended with common polymers, such as of all interior paints and 71% of all high-density polyethylene (HDPE) and exterior coatings.1 Latex paint consists of PMMA, without compromising the four main components in the following mechanical properties of the unfilled proportion: 50% water, 25% acrylic polymers.3 Accordingly, latex paint binder, 15% TiO2 pigment, and 10% could potentially be blended with extenders and additives.1 The acrylic polymers, and these blends may be used component is thermoplastic. in the same unfilled polymer applications The waste latex paint employed in in an effort to recycle the unwanted latex this polymer blend was obtained in solid paint. By blending this waste latex paint form from a corporate source. Since this with PMMA, the financial and paint is taken from the waste stream, environmental burdens associated with there is always the possibility that waste latex paint management could contaminants are present in the paint. potentially be avoided as long as the properties of this immiscible polymer 2.2 PMMA blend, or plastic composite, are similar to Poly (methyl methacrylate), more the properties of PMMA and found to be commonly known as Plexiglas®, is a appropriate for a given application. In a glassy thermoplastic polymer of methyl previous study that tested the properties methacrylate [Figure 1].21 PMMA has a of various paint-polymer blends, the 20- high flexural modulus, high mechanical 80 ratio of Paint-PMMA showed strength, low elongation at break, and properties that in one case even exceeded high shatter resistance.11 Because of its those of unfilled PMMA. Since low water absorption, products made composites often have high stiffness, from PMMA have good dimensional strength, and toughness, further testing stability.11 PMMA is often used as a was desired to corroborate the results of substitute for glass because of its clear the previous study.13 optical properties and can be used for products ranging from swimming pool 3. Method length 63.5 ± 2.0 mm, width 12.70 ± 0.20 mm, thickness 3.0 to 12.7 mm, as dictated 3.1 Sample Preparation by ASTM D256-10 [Figure 4].17 A Ryobi BS902 Band Saw was The injection molding process used to cut large blocks of dried latex was then repeated to mold the PMMA paint into smaller pieces, better suited for with the injection molding machine grinding. Using a modified Nelmor operating at 216 °C and 320 RPM. Both Granulator, the dried latex paint was materials were allowed to rest for 40 ground into flakes. The PMMA was hours before testing commenced as dried in a Lindberg Blue Mechanical dictated by ASTM standards. Oven at 85 °C for 24 hours and the ground latex paint was dried in an Across 3.3 Flexural Testing International Vacuum Drying Oven at For mechanical property testing, room temperature for 24 hours to remove flexural testing is performed on a material absorbed water molecules from the to determine flexural modulus of material. The dried materials were mixed elasticity, flexural strength, and a together in small 100 gram batches — 20 material’s stress-strain curve. The grams latex paint and 80 grams PMMA flexural modulus of elasticity describes — to establish the proper composition the material’s resistance to elastic ratio in preparation for injection deformation and aids in characterizing molding. Comparatively small amounts material failure. Flexural strength is the of carbon black were also added to the stress value at a material’s fracture. It is mixture to achieve a uniform specimen important to note that because flexural coloring throughout the melt-blending strength is the greatest value of stress that process. a material can withstand, it is also the effective strength of a material.8 In this 3.2 Processing analysis, the stress at yield point is taken Injection molding is used to mass- as the effective strength of the tested produce plastic products with varying materials because stress did not increase shapes and designs. It is the most significantly thereafter. Aside from common method for processing recording the flexural stress, it is equally thermoplastics such as PMMA.6 For this important to note the strain at this research, 20-80 wt % Paint-PMMA was point. The strain at yield describes the injection molded to form an immiscible amount of deformation a material can polymer blend using a Negri Bossi V55- undergo prior to experiencing plastic 200 injection molding machine operated deformation.8 at 216 °C and 320 RPM [Figure 2].14 The A three-point flexural bend test mold yielded flexural and impact was completed according to ASTM specimens with dimensions set by the standard D790 using an MTS QTestTM/25 American Society for Testing and controller [Figure 5]. For both materials, Materials (ASTM) for use in testing. The flexural tests were run at a calculated specimens used in flexural testing were span of 52.288 mm and rate of crosshead molded according to ASTM D790 motion of 1.4 mm/min. The same span standards with a width of 13 ± 0.5 mm and rate of crosshead motion was used for and a thickness of 3.2 ± 0.4 mm [Figure both materials as the specimen 3].15, 16 The impact bars were molded at dimensions fit within the standard deviations for these specifications, which 3.5 FTIR Analysis is important for uniformity in analysis Fourier Transform Infrared and comparison. Every tested specimen Spectroscopy (FTIR) uses infrared light was centered on the lower supports with to detect the types of bonds present within the direction of flow pointing the same molecular structures. A range of way and then preloaded to 4 N. In frequencies of infrared light are emitted accordance with ASTM standards, at into the material being tested and data is least five specimens were tested for each collected based on the percent sample.15 transmittance of the light at each particular wavelength. The absorbance at 3.4 Impact Testing a certain infrared wavelength Impact testing is used to corresponds to specific types of determine a material’s ability to resist bonding. Since no two unique bonds will stress being loaded at a rapid rate.8 Using have the same infrared spectrum, the an Instron Dynatup POE 2000, an Izod spectra produced can be used to Impact test was done on both the PMMA determine the bonds present in the and Paint-PMMA according to ASTM material.18 An FTIR test was performed standard D256-10.17 During impact on 3 specimens each of PMMA, latex testing, the pendulum swings and hits the paint, and the Paint-PMMA mixture in material at a pre-made notch. The energy order to characterize the makeup of the absorbed by the material at impact is 20-80 wt % Paint-PMMA blend as recorded and used to determine the Izod compared to the unfilled polymer and impact resistance of the specimen.17 original paint samples. Prior to testing, the impact specimens were manually notched 3.6 DSC Analysis according to ASTM standards at a 45˚ ± Differential Scanning 1˚ angle with a depth under notch of Calorimetry (DSC) measures the thermal 10.16 ± 0.05 mm. Before impact testing transitions of polymers. During DSC, an occurred, a velocity test for the pendulum empty aluminum pan is used as a was run to ensure that its velocity was reference. Meanwhile, the material within ASTM standards. The being tested is placed into another pan pendulum’s velocity was determined to known as the sample pan.4 To determine be 3.46 m/s, meeting ASTM standards.17 the heat capacity of the sample a An impact energy of 2.7 J was inputted temperature sweep is done. The sample before running the impact test. After pan and the reference pan are maintained inputting impact energy and the at the same temperature, so that the specimen’s particular dimensions, which material with the higher heat capacity includes thickness, width, and depth absorbs more heat. The difference in heat under notch, the pendulum swings and absorption is proportional to the breaks the specimen in the vice at the pre- difference of the two materials’ heat notched region and records the impact capacities. As a result, the glass resistance. For each sample, at least ten transition temperature and melting point specimens were tested in compliance of a polymeric sample can be found, as with ASTM standards.17 well as the degree of crystallinity. Glass transition temperature refers to the temperature at which polymer chains gain additional mobility due to bond rotations, mg of the Paint-PMMA composite was and with increased heating are eventually used for this test. able to flow past one another.4 The glass transition temperature is characteristic of 4. Results amorphous polymers and the amorphous region of semi-crystalline 4.1 Flexural Properties polymers. Melting point is the Five specimens were tested for temperature at which crystalline and the PMMA and seven specimens were semi-crystalline polymers lose their tested for the Paint-PMMA as dictated by ordered structure and become liquid- the ASTM standards.15 The stress-strain like.4 curves for both the PMMA and the 20-80 In this research, DSC was wt % Paint-PMMA blend were generated employed to characterize the thermal from the collected stress and strain data properties of PMMA and the paint points [Figure 6, Figure 7]. A component. This testing was done using representative specimen from each a TA Instruments Q1000 Differential sample was selected for comparison and Scanning Calorimeter under an is presented on a separate graph [Figure atmosphere of dry nitrogen. The heat 8]. absorption of PMMA was compared to an Upon testing, both the PMMA aluminum reference pan. Three Heat- and 20-80 wt % Paint-PMMA were found Cool-Heat runs of DSC were completed to have an average modulus of 3.1 GPa with a temperature range of -25 °C to 220 [Figure 9]. Since the modulus of °C at a heating rate of 10 °C per elasticity is a very important property of minute. The three samples were prepared polymers, it is very promising to find that to 10.0 mg ± 1.0 mg. blending the latex paint with the PMMA Modulated DSC (MDSC) differs was not detrimental to its modulus. The from regular DSC in that it measures both PMMA was able to withstand an average the heat capacity and the heat flow of a stress at yield of 100 MPa, while the 20- material in a single temperature ramp by 80 wt % Paint-PMMA blend had an “superimposing a modulated heating rate average stress at yield of 79 MPa [Figure on top of a linear heating rate.” MDSC 10]. The percent strain at yield was “offers increased sensitivity for detection similar for PMMA and Paint-PMMA of weak transitions.”19 In this analysis, blends at 4.95 % and 4.72 %, MDSC was used to measure the thermal respectively. [Figure 11]. transitions of 20-80 wt % Paint-PMMA During testing, two Paint-PMMA in order to observe a more visible change specimens fractured while no specimens in the composite’s glass transition fractured for the PMMA. Upon further temperature than could be observed with examination, noticeable inclusions of regular DSC. The 20-80 wt % Paint- material other than paint or PMMA were PMMA sample underwent a temperature found within the composite on the ramp of -25 °C to 220 °C at 3 °C per fracture surface [Figure minute with a 2 °C modulation 12A]. Contaminants like these act as temperature amplitude every 40 seconds stress concentrations, because the stress using the modulated mode of the TA surrounding the inclusion is higher than Instruments Q1000 Differential Scanning the applied load and results in premature Calorimeter (MDSC). A sample of 10.2 fracture. [Figure 12B]. Thus, the flexural strength of the Paint-PMMA blend might the three trials conducted [Figure be artificially low and may increase with 16]. This indicates that the paint had a a cleaner source of waste paint. varying composition between the samples, which is to be expected with 4.2 Impact Properties mixed, waste paint that may not be of the The impact test is used to same type. The variation occurs most determine the impact resistance of a saliently in the wavenumber range from material by calculating the sample’s 600-1400 cm-1. The FTIR spectra of energy absorbance at impact.8 Impact PMMA and latex paint indicate that they resistance is calculated by dividing the have similar chemistry. total energy absorbed at impact by the The 20-80 wt % Paint-PMMA specimen thickness.8 Throughout the had very uniform spectra that likely tests, specimens underwent a uniform resulted from consistent composition, impact energy due to the pendulum strike thorough mixing, and proper dispersion of 2.7 J at an impact velocity of 3.46 among the 20-80 wt % Paint-PMMA m/s. All specimens exhibited complete specimens [Figure 17]. The three most breaks. The impact resistance was prominent peaks from the FTIR spectra similar for the PMMA sample at 59 J/m of the PMMA remain present in the 20- and the 20-80 wt % Paint-PMMA sample 80 wt % Paint-PMMA spectra, and the at 55 J/m [Figure 13]. The standard Paint-PMMA spectra appear to include deviation of the PMMA sample is larger peaks from both the PMMA and paint at 6 J/m compared to that of 20-80 wt % spectra [Figure 18]. The significance of Paint-PMMA sample at 2 this is that many of the bonds present in J/m. Importantly, the impact resistance the original materials are still present in of the 20-80 wt % Paint-PMMA sample the polymer blend, as is characteristic of fell within the standard deviation of the an immiscible polymer blend. One impact resistance for PMMA. characteristic that very clearly signals the presence of the latex paint in the 20-80 wt 4.3 Structural Properties % Paint-PMMA is the peak at the lower The FTIR spectra of PMMA end of the wavenumber scale, around corresponded very closely to the PMMA 600-750 cm-1, because it is manifest in reference spectra [Figure 14, Figure both the paint and Paint-PMMA 15]. The peak in the 2750-3050 cm-1 spectra.20 range indicates a CH stretching vibration and the following peak around the 4.4 Thermal Properties wavenumber 1730 cm-1 indicate CO In analyzing the DSC results, the double bond stretching vibration. Other glass transition temperature of the peaks in the wavenumber ranges of 1395- PMMA was found to be 105.5 ˚C [Figure 1450 cm-1 and 1040-1260 cm-1 represent 19]. The MDSC graph of the 20-80 wt % CH3/CH2 deformation vibrations and Paint-PMMA displays two glass COC single bond stretching vibrations, transition temperatures of 24.5 ˚C and respectively. The rightmost peak at 800- 96.8 ˚C for the latex portion of the blend 1000 cm-1 indicates a COC single bond and for the PMMA portion of the blend deformation vibration. respectively [Figure 20]. The results of The FTIR spectra for the latex the MDSC initial heat run for the 20-80 paint was not completely uniform over wt % Paint-PMMA mixture demonstrate that the Tg of PMMA is lowered by about PMMA plastic composite would be 9 ˚C when blended with paint. The DSC suitable to replace PMMA in certain tests also confirm that the Paint-PMMA applications because these mechanical composite has two distinct phases—a properties are not sacrificed with the PMMA phase and a latexphase—as is blending of paint and PMMA. It may characteristic in immiscible polymer therefore be feasible to use a Paint- blends. There was no melting PMMA composite as a medium to temperature observed for either PMMA recycle unused latex paint and to or the Paint-PMMA composite, which subsequently use the composite in means that neither material has a specific applications as a substitute for crystalline structure. This result is PMMA. However, the marginally lower consistent with the amorphous form of yield strength of the 20-80 wt % Paint- PMMA. PMMA composite reflects that the material will begin to plastically deform 4.5 Possible Sources of Error under less stress than PMMA itself and is Upon observing the flexural therefore not appropriate to replace fracture surfaces of two 20-80 wt % PMMA in all applications. Further Paint-PMMA specimens, white investigation should be completed to contaminants were visible [Figure determine the response of Paint-PMMA 12]. Contaminants in waste-sourced blends to stresses applied over a long materials are a common problem and act period of time as compared to the as stress concentrations within the response of PMMA. Therefore, latex polymer blend, which causes pre-mature paint blended with PMMA has potential fracture during mechanical property to serve as a material that can ameliorate testing. To address this problem, one can some of the burden of disposing unused improve the collection process to better paint by creating an immiscible polymer clean the waste materials and also use blend with comparable mechanical recycled materials to fabricate parts with properties to PMMA. large cross-sections, in which the effect of the contaminants is minimized. 6. Acknowledgements 5. Conclusion This research project could not Waste latex paint was collected, have been completed without the help of dried, and injection molded with many, so we would like to extend our PMMA to prepare an immiscible gratitude to those that made it polymer blend of 20 wt % paint and 80 wt possible. We would like to thank our % PMMA. The flexural, impact, thermal, project mentors, Dr. Jennifer Lynch and and structural properties were Jamie Wooding, for guiding us characterized for the 20-80 wt % Paint- throughout the entire process. They were PMMA blend and for neet PMMA. The an invaluable resource to us. We would Paint-PMMA blend demonstrated a also like to especially thank our modulus of elasticity equal to that of Residential Teaching Assistant, Kelly PMMA and similar impact Ruffenach. Her enthusiasm and resistance. These two characteristics knowledge encouraged us to work indicate that the 20-80 wt % Paint- diligently toward our goals. We are grateful to have had Arya Tewatia, Ryan Material Science of Polymers for Szeto, and Dr. Thomas Nosker share their Engineers. 3rd ed. Munich: Carl knowledge with us. This project could Hanser Verlag, 2012. Print. not have been made possible without 5 “Thermosetting vs. Thermoplastic Director Dr. Ilene Rosen and Associate Polymers." N.p., n.d. Web. 16 Director Jean Patrick Antoine; without July 2015. them, this program would not be possible. 8. Figures Figure 1. Repeating unit of PMMA Figure 2. In injection molding, the material is fed through the hopper, pressurized and heated in the plasticizing/feed screw, fed through the nozzle into the mold, and ejected upon cooling. Figure 3. 20-80 Paint-PMMA and Figure 4. 20-80 Paint-PMMA and PMMA flexural specimens as molded PMMA impact specimens according to according to ASTM D638-08 tensile ASTM D256 dimensions11 bar dimensions16 Figure 5. A three-point flexural bend test being performed on a 20-80 Paint-PMMA flexural specimen Figure 6. Stress-Strain curves for PMMA Figure 7. Stress-Strain curves for 20-80 Paint-PMMA Figure 8. Stress-Strain curves for a representative specimen from both the PMMA and 20-80 Paint-PMMA specimens Figure 9. Flexural Modulus for PMMA and 20-80 Paint-PMMA Figure 10. Stress at Yield (MPa) for PMMA and 20-80 Paint-PMMA Figure 11. Percent Strain at Yield for PMMA and 20-80 Paint-PMMA Figure 12. Both images show the fracture of a 20-80 Paint-PMMA flexural specimen. A) The fracture surface shows contamination B) An uneven fracture surface indicated by the white inclusions. . Figure 13. Impact Resistance (J/m) for PMMA and 20-80 Paint-PMMA Figure 14. Reference FTIR Spectra for PMMA Figure 15. FTIR Spectra for 3 specimens of PMMA Figure 16. FTIR Spectra for 3 Paint samples Figure 17. FTIR Spectra for 3 specimens of 20-80 Paint-PMMA Blue = PMMA Red = Paint-PMMA Black = Paint Figure 18. FTIR Spectra overlay with a representative specimen of from PMMA, Paint, 20-80 Paint-PMMA Figure 19. DSC of PMMA Figure 20. MDSC of 20-80 Paint-PMMA