We don't have a good mechanism for waterproofing cellulose without various complicated industrial processes. Finding a way to do that would be interesting research.

But anything involving grapeviles is just ecomasturbation.

Actually, no, it's worse, because it robs attention and funding from real problems. Plastic pollution isn't predominately plastic bags or (plastic straws for that matter) that seem important because the sort of person who writes articles on a laptop for online publication encounters them daily and doesn't see the stream of untreated industrial waste mostly from the big rivers in Asia.

IMHO, the best investment in mitigation of plastic pollution would be automatic cleanup mechanisms, especially for microplastics in the ocean.

In fairness, those industrial waste streams are mostly produced by “recycling” facilities for consumer waste.

The whole plastic straw thing is nuts. The old waxed paper straws were fine. The new “paper” straws are coated in PFAS and way worse for your health and the environment than most alternatives.

This article reminds me of that. Cellulose isn’t a new technology, but, like wax paper straws, it’s apparently forgotten arcane knowledge.

It's interesting to me that you think the point of greatest effectiveness is exactly where I'd say realistically all hope is lost, the oceans being so vast of a surface and volume. This is end-of-pipe thinking where I believe we should really start at one of the many points earlier in the process: industrial consumption of materials and industrial waste management are such points, and as you say protection of waterways from pollution. Given how lousy mankind has proven to be when it comes to collecting and effectively re-using plastic waste while avoiding concomitant pollution of water and air and material down-cycling, the real mistake lies in the sheer enormous tonnage-per-year and its growth of plastic. This volume of production should have never happened in the first place. But of course it has so there's a place for ocean cleanup efforts. But to state that "the best investment [...] would be automatic cleanup mechanisms" while denigrating research efforts to produce better plastic-ersatz to me sounds like futuristic techno-boondoggle-babble, not unlike that crazy 'hyperloop' thing. Automatic ocean cleanup robots! Yaay! LA to NY in under 30 minutes! Yaay! Colonies on Mars! Yaa---wait wot?? People can't even cleanup after themselves or avoid throwing their trash into the next river, but no problem, we'll clean that up in no time AUTOMATICALLY?? C'mon give me a break.