Source: NOVOL, INC. submitted to NRP
CORN BASED CHEMISTRIES FOR MAKING RENEWABLE OPTICAL POLYMERS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
Reporting Frequency
Annual
Accession No.
1016028
Grant No.
2018-33610-28261
Cumulative Award Amt.
$100,000.00
Proposal No.
2018-00465
Multistate No.
(N/A)
Project Start Date
Jul 1, 2018
Project End Date
Feb 28, 2019
Grant Year
2018
Program Code
[8.8]- Biofuels and Biobased Products
Recipient Organization
NOVOL, INC.
510 PORPOISE BAY TER APT D
SUNNYVALE,CA 94089
Performing Department
(N/A)
Non Technical Summary
In summary, this proposal will build a route to industrial manufacturing of a commercially viable polymeric material using Corn-based monomers like Isosorbide, test these methods and demonstrate a path to a prototype product. Work presented in this proposal is novel and unique in the following ways:First application of Isosorbide for making optical polymersFirst report of non-brittle Isosorbide polymers of refractive index >=1.52First report of utilizing high Abbe values of Isosorbide polymers for making lensesFirst report of casting Isosorbide into a thick slab useful for cutting out a lensSuccess of this work will not only promote our internal goals of making bio-based lenses but it will provide a rare example of a commercially viable chemistry based on Isosorbide. So far, Durabio is the best example of Isosorbide traction in markets. We have spoken to both Mitsubishi (maker of Durabio) and Iowa Corn Board (owner of a lot of IP in Isosorbide production and processing) regarding our invention and received their support in promoting our Polymers in optical markets to provide Isosorbide the much-needed traction and to demonstrate a route to making clear, non-yellowing Isosorbide products. Through our product, we hope to serve both the USDA goals of enhancing the use of crops and agricultural materials in current markets through bio-based materials as well as creating a value chain from sustainable resources.
Animal Health Component
100%
Research Effort Categories
Basic
(N/A)
Applied
100%
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
51115102000100%
Knowledge Area
511 - New and Improved Non-Food Products and Processes;

Subject Of Investigation
1510 - Corn;

Field Of Science
2000 - Chemistry;
Goals / Objectives
Major goals of this project are to1. Demonstrate a scalable process for making a novel corn-based polymer that is useful foroptical and ophthalmic applications.2. Demonstrate the process to convert this polymer into a lens.The current project is derived from Novol's previous work in the area of making optical polymers using corn-derived chemistries like Isosorbide and Glycerol that are bio-based. If successful, this project will be able to build a high impact resistant material of useful properties like high refractive index and low dispersion. Such properties are essential for making eyeglasses. At present, 40% of the world's population wears prescription eyeglasses. Further, an estimated 70% uses sunglasses, and with the onset of digital age, 100% is recommended to wear some eyewear to protect their eyes from blue light. As such, the need for this category of polymers is and will remain high in the coming years. Facts suggest that in 2015, 2 billion pairs of eyeglasses or 4 billion lenses were dispensed, which amounts to an estimated need for 200 million kg of optical polymers. Material properties are a function of monomers chemical structure. We have built an inventory of polymers made from Isosorbide that have good transparency and optical attributes. However, on its own, most Isosorbide based polymers are brittle. Our previous work guided a path for making non-brittle optical polymers that we will expand on this USDA SBIR proposal. To begin with, the R&D work of this Phase I grant will verify the polymer reaction yields desired properties. Then we will scale the polymer from gram scale to kg scale by applying the reaction chemistry in larger scale reactors that mimic industrial conditions, mainly controlled temperature, pressure and agitation.Once we obtain the polymer, we will use our molding technology to make lenses from this polymer. The lenses will be made in sizes and geometries that are suitable for eyeglass use and also for camera assemblies. These are two of the largest markets for lenses currently and our goal in Phase I is to demonstrate the feasibility of this project for both the eyewear and the camera market.Work done during this Phase I will set up the foundation of Phase II goals wherein we will complete the feasibility studies by adding rigor to our work through targeted scale-up of the polymer. The molding method will be developed much further during Phase I, as we will translate the molding conditions to an industrial molding press, identify the optimal conditions for molding each type of lens and identify a process for taking the lens making technology platform to an actual OEM.
Project Methods
Specific Aims provided in this proposal which are:Explore potential of commercial opportunity for NOVOL-22 in lens marketsBenchmark NOVOl-22 vis-à-vis current materials and lenses.For completion of Specific Aim 1, we will use the following methods to accomplish 3 key goals:Reproduce the reaction conditions at small scale: To begin with this project will employ methods that have been previously established to make a proof of concept polymer, and thin films of it. For the polymer production, we will replicate the following synthetic scheme provided below to ensure that the scheme is validated as part of this project work.Chemical SynthesisIn a thermochemical reaction performed at 75°C with agitation, the two OH groups of Isosorbide react with the NCO groups of 2 Isocyanates and a cross-linking reagent to make tough polyurethanes, in the presence of a catalyst. After 12 hours, all the monomers are consumed and the reaction produces a high molecular weight polymer of molecular weight n >10,000 Daltons as a product, along with some lower molecular weight polymer. The high molecular weight polymer is separated from other reaction components by using the difference in its molecular weight and therefore solubility, relative to other components to achieve >95% purity. Purity is essential to ensure product consistency when making a lens and remove elements that may cause haze and interfere with light transmission.Once the scheme is confirmed, we will attempt to accomplish the next 3 goals aimed at scale-up of process.Reproduce the reaction conditions at 1kg scale: We will first attempt to repeat our lab scale synthesis of SC-22 at larger scale (Several kgs) in bigger reactors to obtain 1 kg of polymer - enough for making 10-15 lenses. Establish conditions to run reaction in industrial reactors: A controlled reactor with fine control of temperature is specifically useful for making bio-based polymers. It is our experience that using sugar based monomers can sometimes yield inconsistent results in color. This may be due to low level of heating control at small scales, that can create pockets of high temperature, causing unnecessary yellowing. In Specific Aim 2, we will test the reaction scheme in a controlled reactor like Parr reactor that is equipped with temperature, pressure and agitation controls. High level of mixing is critical to increase the reaction yields during later phase when reaction viscosity increases with increase in degree of polymerization.Improve mass yields of high molecular weight polymer: Molecular weight distribution in any polymerization follows a gaussian curve. At lab scale, our polymerization reaction shows that out of the total polymer formed (92% polymer yields on initial monomers), the desired high molecular weight polymer is about 78% (72% mass yields on initial monomers). During scale-up, we will optimize the reaction conditions so that mass yields of our desired product increase to >80%.Project sites: Novol currently works in our lab space in San Leandro, CA. We also work in collaboration with the Polymer center at University of Toledo in Ohio, which has several Parr reactors [both small scale (25-30g) as well as large scale (3L capacity, 2-2.5 kg polymer)]. We also have access to collaborative sites in University of Berkeley (QB3) to use their polymer lab facilities. Recently, we have gained access to the Molecular Foundry User Program at Lawrence Berkeley National Lab for an opportunity to use their facilities pro bono, through our selection as one of the companies that qualified for their annual competition.Specific Aim 2: Create prescription (also called Rx) Lenses, and Camera Lenses from NOVOL-22 polymerMilestone: A lens of 10mm thickness and 70mm diameter made from NOVOL-22Methods to prepare lens blanks and Rx lenses from polymer resins depends on the physical and thermal properties of the polymer. Tg (glass transition temperature), melt profile, flow and rheological characteristics of the polymer, and its thermal decomposition behavior affect the lens making process.In Specific Aim 2, we will test a method devised by Novol's CTO, Jagdish Jethmalani to cast a prescription lens and a camera lens. Although our market position is to sell semi-finished lenses, we believe that it is necessary to show that our lens material can lead to a final product like a prescription or a camera lens. This will allow customers to test our prototype.Thermoforming Process for making Lens Blanks and Rx Lenses: Our polymer will be made into lens blanks for Rx lenses by a process called Thermoforming which was explained in great detail in our grant proposal. Steps to make a Rx lens include:1. Polymer Synthesis (already described in Aim 1.)2. Slab Formation - Thin slab (1.5mm) of Polymer is created by pouring into square molds & heated under pressure.3. Rx Lenses forming - In this step, slabs are reshaped by heating above the softening temperature to cut out thin lenses of desired prescriptions. This step is specific to the geometries of front and back molds of a prescription lens. Our CTO, Jagdish is an expert in making Rx lenses. Under his guidance, we will make Front molds of different spherical curvatures (2, 4, 6, and 8D) and back molds of -6D to +6D spherical curvature in 0.25D steps. We will also add cylinder molds of 0 to -4D in 0.25D steps, rotatable from 0-180° in 1° increments. Range of prescription lenses that we will get using this process covers the process for making prescriptions for more than 90+% of world population.4. Coatings - Front and back surfaces of lenses are spin coated with hard coat resin (from Ultra Optics, MN), UV-cured and followed by anti-reflective (AR) coating on both surfaces by vacuum deposition to form finished Rx lenses.5. QC Inspection & Packaging - Lenses are checked for several parameters, including: Sphere/Cylinder/Axis, Optical Center and Thickness Tolerances, and Cosmetic properties.Similarly we described the processing of manufacturing Camera lenses. Polymer slabs can be reshaped to convex, plano-convex, concave, achromat (concave-convex of low Abbe/convex of high Abbe), micro to small diameter lenses by thermoforming process. The thermoformed lenses can be hard and AR coated and 4-6 lenses can be optically aligned to form optical systems, that will make the camera assembly.Project Sites:The thermoforming process needs some specialized equipment as well as molds. We have purchased molds of various diopters and will use a melt press at the UC Berkeley Nanofabrication Lab to form thin slabs from our polymer. Further testing will be done at Novol's lab facilties, where we have additional equipment to cut the slabs into spherical discs.As the last goal, we will need to test our lenses against standard measures of mechanical and optical characteristics. This is described below.Testing of Rx Lenses: The Rx lenses must meet all the ANSI standards in addition to ISO standard (ISO 14889) for Ophthalmic Optics/Spectacle lenses. Some of the tests under these ANSI and ISO standards for Rx lenses include Rx power (Sphere/Cylinder/Axis), FDA Ball Drop, Resistance to Ignition, Hard Coat Adhesion, QUV, Environmental, and Biocompatibility Testing. Lenses for cameras undergo most of the same tests except the tests for Rx power.Project Sites:Tests for Rx and camera lenses will be performed both internally at Novol and at Colts Laboratories (FL), along with our work on refractive index and Abbe value measurements with Metricon and Filmetrics.

Progress 07/01/18 to 02/28/19

Outputs
Target Audience:Target audience for our technology is the eyeglass wearing customer. Total addressable market: $8 billion in the US, $20 billion Worldwide. Prescription eyewear is a $100 billion industry, serving 2+ billion people. A report by Essilor, largest lens manufacturer in the world, shows the size of Essilor's Prescription Eyewear revenue globally (Figure 3), which is >80% of world market. Americans buy 80 million pairs a year, about a third of the global total. 10% of sales today are direct to consumer online. Direct to consumer retailers like Warby-Parker took the eyewear industry to main street and today own about 8% of total online sales channel. Our goal is to leverage the B2C online + retail business model started by companies like Warby Parkerthat takes the sales away from traditional doctor's office. It is expected that this sales channel will triple in numbers in coming years . Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided?Opportunity to learn synthetic organic chemistry to convert agircuturally derived sugars into optical polymers Methods of molding these polymers into lenses How have the results been disseminated to communities of interest? Nothing Reported What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? Phase I Milestone: Remake polymer SC2-22 by further optimization with improved yield Status: Completed The initial proof-of-concept work on synthesizing the polymer SC2-22 was re-attempted by Novol. The polymers obtained from the one-pot synthesis, were non-brittle and the reaction yield was above 90%, which is an improvement over SC2-22 polymer mentioned in the Phase I application. However several batches of the polymer reaction mixtures were faint yellow in color which resulted in a yellow final product after purification and the final polymer yield after purification was only 70%. Moreover some of the polymer films made of the yellow colored polymer were unable to pass the ball drop test as they lack a certain degree of mechanical strength. In order to obtain high yielding reaction mixture with non-yellow, tough polymer, we optimized the reaction conditions and minimized the variables. We have modified the reaction conditions in terms of purity of monomers, time of addition of crosslinker and the crosslinker amount, overall reaction time, and purification protocol of the isolated polymer so that mechanically strong, optically transparent and colorless lenses can be fabricated. These modified polyurethanes, SC2-22X, are more rigid, optically transparent and colorless compared to SC2-22. Such refinements also resulted in polymers with near quantitative, meaning 100%,yield. Conclusions of Specific Aim 1 We have successfully been able to optimize, verify and repeat the process for the synthesis of SC2-22X. The refined synthetic procedure resulted in non-yellow polymer, SC2-22X, with near quantitative yield at shorter reaction time. The polymer slabs are optically clear. In order to enhance the mechanical properties of the modified polymer, we have increased the amount of crosslinker and altered the time of addition. It is worth mentioning here that a bump free lens can only be realized with the finest possible grains of polymer powders after sieving the grounded polymers through fine mesh. Since the yield of the sieved polymers resulted after addition of glycerol at 15 min (SC3-64, entry 3, Table 2) and 30 min (SC3-58, entry 4, Table 2) time intervals are very low due to their high rigidity, we selected SC2-22X, the rigid polymer obtained after addition of glycerol at 60 min to scale up for making prototypes as the polymer is relatively easy to grind and sieve before molding. The very rigid polymers like SC3-64 and SC3-58 requires further optimization in terms of grinding and sieving and subsequent molding into lenses before scale-up. Phase I Milestone: Make multiple batches and verify reproducibility Status: In-Progress We have been able to scale up the polymer SC2-22X successfully to 50 g and 250 g quantities in our lab using larger glass reaction vessels. The different batches of scaled up synthesis have produced polymers whose optical property and mechanical property are consistent with each other. In addition, the isolated yields of the pure polymers are quantitative. However, given the small lab space, it is difficult to scale up the polymer to 1 kg scale using the existing equipment. Scaling up of a polymer to kilogram scale requires large reactors with precise temp controls, proper agitator for desired level of agitation and other significant control mechanisms. Hence, we have initiated conversation with Roquette, the world-wide largest manufacturer and provider of Isosorbide, to help scaling up the polymer at their facility with appropriate reactors, controls and equipment. We are confident that we can jointly develop an industrially safe protocol working with a large partner such as Roquette to scale up to tens of kilo quantities as our scale up has produced excellent yields of our polymer at high purity. Specific Aim 2: Create lens blank, Rx lenses, camera lenses from SC2-22 polymer Phase I Milestone: Mold several lens blanks and prescription lenses Status: Completed We have developed a method of making semi-finished lens blanks and finished prescription eyeglass lenses my melt compression process directly from the polymer powders at our facility (5, 6, 7, 8). Instead of making thick polymer slabs inside stainless steel molds by compression and subsequent reshaping the slabs into specific prescription lenses by heating above the softening temperature inside the glass molds of desired prescriptions, we developed a direct process to make the semi-finished lens blank and finished Rx lenses of desired center thickness from the polymer powders by using glass molds of known front and back radii, spacer thickness and prescription. At high temperature, the powdered polymer softens, melts, and fuses together by taking the shape of the front and back glass molds when pressed together in between these molds under pressure and solidify under slow cooling with air. This entire process of making lenses takes ~1 h excluding the time needed for the preparation of the glass molds. This will help make finished Rx lenses with less amount of waste and fast production time which in turn will help reduce the delivery time to the optometrist/optician who can dispense the complete eyewear to the patients. We provide here data and proof of our successful compression molding process using glass molds for making prescription eyeglass lenses.

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